Sample records for methylparaben ethylparaben propylparaben

  1. A New Validated HPLC Method for the Simultaneous Determination of 2-phenoxyethanol, Methylparaben, Ethylparaben and Propylparaben in a Pharmaceutical Gel.

    PubMed

    Shabir, G A

    2010-07-01

    A novel reversed-phase HPLC method has been developed and validated for the simultaneous determination of 2-phenoxyethanol, methylparaben, ethylparaben and propylparaben preservatives. The method uses a Lichrosorb C8 (150×4.6 mm, 5 µm) column and isocratic elution. The mobile phase consisted of a mixture of acetonitrile, tetrahydrofuran and water (21:13:66, v/v/v), pumped at a flow rate of 1 ml/min. The UV detection was set at 258 nm. The method was validated with respect to accuracy, precision (repeatability and intermediate precision), specificity, linearity and range. All the parameters examined met the current recommendations for bioanalytical method validation. The developed method was successfully applied to the determination of commercially available pharmaceutical gel products for these preservatives. The procedure describes here is simple, selective and reliable for routine quality control analysis and stability tests. PMID:21218050

  2. HPLC METHOD FOR DETERMINATION OF PARACETAMOL, PSEDOEPHEDRINE, TRIPROLIDINE, METHYLPARABEN, PROPYLPARABEN, SODIUM BENZOATE AND THEIR RELATED SUBSTANCES IN PHARMACEUTICAL SYRUP

    Microsoft Academic Search

    Alaa El-Gindy; Khalid Abdel-Salam Attia; Mohammad Wafaa Nassar; Hamed Hamed Abu Seada; Maisra Al-Shabrawi Shoeib

    2012-01-01

    A validated HPLC method was developed for the analysis of paracetamol, psedoephedrine, triprolidine, methylparaben, propylparaben, sodium benzoate and their related substances including p-aminophenol, triprolidine Z-isomer, 4-hydroxy benzoic acid and 4-chloracetailide in syrup using symmetry C18 column at 25°C with UV detection at 214 nm. A linear gradient elution was employed starting with 100% mobile phase A and 0% mobile phase B

  3. Determination of methylparaben, propylparaben, triamcinolone acetonide and its degradation product in a topical cream by RP-HPLC.

    PubMed

    Matysová, L; Hájková, R; Sícha, J; Solich, P

    2003-06-01

    A novel reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed and validated for the determination of active component triamcinolone acetonide, its degradation product triamcinolone (occurring in formulation after long-term stability tests) and two preservatives presented in the cream-methylparaben and propylparaben, using hydrocortisone as an internal standard. The chromatographic separation was performed on a Supelco Discovery C18 column; the mobile phase for separation of all compounds consists of a mixture of acetonitrile and water (40:60 v/v). The analysis time was less than 9 min, at a flow rate of 0.6 mL min(-1) and detection at 240 nm. The method was found to be applicable for routine analysis (stability tests, homogeneity) in the pharmaceutical product topical cream Triamcinolon cream 0.1%. PMID:12819846

  4. Development and Validation of a Stability-Indicating LC-Method for the Simultaneous Estimation of Levodropropizine, Chloropheniramine, Methylparaben, Propylparaben, and Levodropropizine Impurities.

    PubMed

    Kumar, Palakurthi Ashok; Raju, Thummala Veera Raghava; Thirupathi, Dongala; Kumar, Ravindra; Shree, Jaya

    2013-03-01

    A simple, fast, and efficient RP-HPLC method has been developed and validated for the simultaneous estimation of Levodropropizine, Chloropheniramine, Methylparaben, Propylparaben, and the quantification of Levodropropizine impurities in the Reswas syrup dosage form. A gradient elution method was used for the separation of all the actives and Levodropropizine impurities by using the X-Bridge C18, 150 mm × 4.6 mm, 3.5 ?m column with a flow rate of 1.0 mL/min and detector wavelength at 223 nm. The mobile phase consisted of a potassium dihydrogen orthophosphate buffer and acetonitrile. All the peaks were symmetrical and well-resolved (resolution was greater than 2.5 for any pair of components) with a shorter run time. The limit of detection for Levodropropizine and its Impurity B was 0.07 ?g/ml & 0.05 ?g/ml, whereas the limit of quantification was 0.19 ?g/ml & 0.15 ?g/ml respectively. The method was validated in terms of precision, accuracy, linearity, robustness, and specificity. Degradation products resulting from the stress studies were well-resolved and did not interfere with the detection of Levodropropizine, Chloropheniramine, Methylparaben, Propylparaben, and Levodropropizine Impurity B, thus the test method is stability-indicating. Validation of the method was carried out as per International Conference on Harmonization (ICH) guidelines. PMID:23641334

  5. Development and Validation of a Novel Stability-Indicating RP-HPLC Method for the Simultaneous Determination of Halometasone, Fusidic Acid, Methylparaben, and Propylparaben in Topical Pharmaceutical Formulation

    PubMed Central

    Goswami, Nishant; Gupta, V. Rama Mohan; Jogia, Hitesh A.

    2013-01-01

    A stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed for the simultaneous determination of halometasone, fusidic acid, methylparaben, and propylparaben in topical pharmaceutical formulation. The desired chromatographic separation was achieved on an Agilent Zorbax CN (Cyano), 5 ?m (250 × 4.6 mm) column using gradient elution at 240 nm detector wavelength. The optimized mobile phase consisted of a mixture of 0.01 M phosphate buffer and 0.1% orthophosphoric acid, pH-adjusted to 2.5 with an ammonia solution as solvent-A and acetonitrile as solvent-B. The developed method separated halometasone, fusidic acid, methylparaben, and propylparaben in the presence of known impurities/degradation products. The stability-indicating capability was established by forced degradation experiments and separation of known and unknown degradation products. The developed RP-HPLC method was validated according to the International Conference on Harmonization (ICH) guidelines. This validated method was applied for the simultaneous estimation of HM, FA, MP, and PP in commercially available cream samples. Further, the method can be extended for the estimation of HM, FA, MP, and PP in various commercially available dosage forms. PMID:23833716

  6. Development and Validation of a Stability-Indicating RP-HPLC Method for the Simultaneous Determination of Phenoxyethanol, Methylparaben, Propylparaben, Mometasone Furoate, and Tazarotene in Topical Pharmaceutical Dosage Formulation.

    PubMed

    Roy, Chinmoy; Chakrabarty, Jitamanyu

    2013-12-01

    A stability-indicating RP-HPLC method has been developed and validated for the simultaneous determination of phenoxyethanol (PE), methylparaben (MP), propylparaben (PP), mometasone furoate (MF), and tazarotene (TA) in topical pharmaceutical dosage formulation. The desired chromatographic separation was achieved on the Waters X-Bridge™ C18 (50×4.6mm, 3.5?) column using gradient elution at 256 nm detection wavelength. The optimized mobile phase consisted of 0.1%v/v orthophosphoric acid in water as solvent-A and acetonitrile as solvent-B. The method showed linearity over the range of 5.88-61.76 ?g/mL, 0.18-62.36 ?g/mL, 0.17-6.26 ?g/mL, 0.47-31.22 ?g/mL, and 0.44-30.45 ?g/mL for PE, MP, PP, MF, and TA, respectively. The recovery for all of the components was in the range of 98-102%. The stability-indicating capability of the developed method was established by analysing the forced degradation samples, in which the spectral purity of PE, MP, PP, MF, and TA along with the separation of degradation products from the analyte peaks was achieved. The proposed method was successfully applied for the quantitative determination of PE, MP, PP, MF, and TA in a cream sample. PMID:24482766

  7. Quality by Design-Based Development of a Stability-Indicating RP-HPLC Method for the Simultaneous Determination of Methylparaben, Propylparaben, Diethylamino Hydroxybenzoyl Hexyl Benzoate, and Octinoxate in Topical Pharmaceutical Formulation

    PubMed Central

    Roy, Chinmoy; Chakrabarty, Jitamanyu

    2014-01-01

    Abstract A stability-indicating RP-HPLC method has been developed and validated for the simultaneous determination of methylparaben (MP), propylparaben (PP), diethylamino hydroxybenzoyl hexyl benzoate (DAHHB), and octinoxate (OCT) in topical pharmaceutical formulation. The desired chromatographic separation was achieved on the KinetexTM C18 (250 × 4.6 mm, 5 ?m) column using gradient elution at 257 nm detection wavelength. The optimized mobile phase consisted of a buffer : acetonitrile : tetrahydrofuran (60 : 30 : 10, v/v/v) as solvent A and acetonitrile : tetrahydrofuran (70 : 30, v/v) as solvent B. The method showed linearity over the range of 0.19–148.4 ?g/mL, 0.23–15.3 ?g/mL, 1.97–600.5 ?g/mL, and 1.85–451.5 ?g/mL for MP, PP, DAHHB, and OCT, respectively. Recovery for all the components was found to be in the range of 98–102%. The stability-indicating capability of the developed method was established by analysing the forced degradation samples in which the spectral purity of MP, PP, DAHHB, and OCT, along with the separation of the degradation products from the analyte peaks, was achieved. The proposed method was successfully applied for the quantitative determination of MP, PP, DAHHB, and OCT in the lotion sample. The design expert with ANOVA software with the linear model was applied and a 24 full factorial design was employed to estimate the model coefficients and also to check the robustness of the method. Results of the two-level full factorial design, 24 with 20 runs including four centrepoint analysis based on the variance analysis (ANOVA), demonstrated that all four factors, as well as the interactions of resolution between DAHHB and OCT are statistically significant. PMID:25853065

  8. 21 CFR 582.3670 - Propylparaben.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3670 Propylparaben. (a) Product. Propylparaben (propyl p -hydroxybenzoate). (b)...

  9. 21 CFR 582.3670 - Propylparaben.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3670 Propylparaben. (a) Product. Propylparaben (propyl p -hydroxybenzoate). (b)...

  10. 21 CFR 582.3670 - Propylparaben.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3670 Propylparaben. (a) Product. Propylparaben (propyl p -hydroxybenzoate). (b)...

  11. 21 CFR 582.3670 - Propylparaben.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3670 Propylparaben. (a) Product. Propylparaben (propyl p -hydroxybenzoate). (b)...

  12. 21 CFR 556.390 - Methylparaben.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Methylparaben. 556.390 Section 556.390...New Animal Drugs § 556.390 Methylparaben. A tolerance of zero is established for residues of methylparaben in milk from dairy...

  13. 21 CFR 582.3490 - Methylparaben.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3490 Methylparaben. (a) Product. Methylparaben (methyl p -hydroxybenzoate). (b)...

  14. 21 CFR 582.3490 - Methylparaben.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3490 Methylparaben. (a) Product. Methylparaben (methyl p -hydroxybenzoate). (b)...

  15. 21 CFR 582.3490 - Methylparaben.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3490 Methylparaben. (a) Product. Methylparaben (methyl p -hydroxybenzoate). (b)...

  16. 21 CFR 582.3490 - Methylparaben.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 582.3490 Methylparaben. (a) Product. Methylparaben (methyl p -hydroxybenzoate). (b)...

  17. Simultaneous determination of electroactive and non-electroactive food preservatives by novel capillary electrophoresis with amperometric detection

    Microsoft Academic Search

    Weiyu Wang; Yiping Wang; Junbo Zhang; Qingcui Chu; Jiannong Ye

    2010-01-01

    A novel capillary electrophoresis and amperometric detection method was achieved by adding an electroactive additive (3,4-dihydroxybenzylamine, 3,4-DHBA) to the running buffer, so that both electroactive and non-electroactive food preservatives were simultaneously determined. Under the selected optimum conditions, four electroactive preservatives (methylparaben, ethylparaben, propylparaben and butylparaben) and two non-electroactive preservatives (potassium sorbate and sodium lactate) were well separated and sensitively detected

  18. ULTRASOUND-ASSISTED EMULSIFICATION MICROEXTRACTION OF SOME PRESERVATIVES FROM COSMETICS, BEVERAGES AND WATER SAMPLES

    Microsoft Academic Search

    Yadollah Yamini; Abolfazl Saleh; Mohammad Rezaee; Leila Ranjbar; Morteza Moradi

    2012-01-01

    In the present work an efficient method based on ultrasound-assisted emulsification microextraction was developed for the determination of sodium benzoate (SB), p-hydroxybenzoic acid (PHBA), methyl-paraben (MP), ethyl-paraben (EP) and propyl-paraben (PP) in different samples. In this procedure, 40 µL of (5% w\\/v) aliquat 336 in 1-octanol was injected slowly into a 12 mL home-designed centrifuge glass vial containing an aqueous sample of

  19. Identification of ethylparaben as the antimicrobial substance produced by Brevibacillus brevis FJAT-0809-GLX.

    PubMed

    Jianmei, Che; Bo, Liu; Zheng, Chen; Huai, Shi; Guohong, Liu; Cibin, Ge

    2015-03-01

    In this study, crude antimicrobial extract from the culture supernatant of Brevibacillus brevis FJAT-0809-GLX was extracted, and its antimicrobial activity was investigated with the agar diffusion method. The results showed that the antimicrobial activity of the culture supernatant of B. brevis FJAT-0809-GLX increased with the extension of the incubation time of B. brevis FJAT-0809-GLX. The antimicrobial spectrum assays showed that this crude antimicrobial extract from culture supernatant of B. brevis FJAT-0809-GLX could inhibit the growth of both bacteria and fungi. A heat stability test was performed, and different temperatures (30°C, 50°C and 70°C) did not affect the antibiotic activity of this crude antimicrobial extract. The crude antimicrobial extract was also tolerable to changes in pH levels. Its antibiotic activity against Escherichia coli was stable at pH 1 to pH 11, with zone sizes ranging from 18.46mm to 22.19mm. Almost all of the crude extracts extracted using different solvents showed variable degrees of inhibition zones against E. coli, with zone sizes ranging from 17.29mm to 19.62mm, except petroleum ether and butanol extracts, which were found to be completely inactive. Purification of the antimicrobial components was carried out using a column chromatographic technique with column chromatography grade silica gel and analyzed by an Agilent 7890A Network GC system. The separated compound was identified as ethylparaben, with a retention time of 21.980min and a relative amount of 95.50%. The antimicrobial activity of ethylparaben on different types of bacteria and fungi was investigated, and ethylparaben was shown to inhibit different types of microbes to different extents. To the best of our knowledge, this is the first report demonstrating that the bacterium B. brevis could produce ethylparaben. PMID:25542595

  20. Methylparaben potentiates UV-induced damage of skin keratinocytes

    Microsoft Academic Search

    Osamu Handa; Satoshi Kokura; Satoko Adachi; Tomohisa Takagi; Yuji Naito; Toru Tanigawa; Norimasa Yoshida; Toshikazu Yoshikawa

    2006-01-01

    For many years, methylparaben (MP) has been used as a preservative in cosmetics. In this study, we investigated the effects of ultraviolet-B (UVB) exposure on MP-treated human skin keratinocytes. HaCaT keratinocyte was cultured in MP-containing medium for 24h, exposed to UVB (15 or 30mJ\\/cm2) and further cultured for another 24h. Subsequent cellular viability was quantified by MTT-based assay and cell

  1. Methylparaben in Anopheles gambiae s.l. sugar meals increases longevity and malaria oocyst abundance but is not a preferred diet.

    PubMed

    Benedict, Mark Q; Hood-Nowotny, Rebecca C; Howell, Paul I; Wilkins, Elien E

    2009-03-01

    The antimicrobial and antifungal chemical methylparaben (methyl-4-hydroxybenzoate) was added to the adult sucrose diet of Anopheles gambiae and Anopheles arabiensis, and its effect on longevity was determined. In all cases, significant increases in longevity were observed when 0.2% (w/v) methylparaben was added to meals that were refreshed weekly. When fresh sugar diet was refreshed daily, no increase in longevity was observed due to methylparaben suggesting that the effect of methylparaben is to preserve the quality of the sugar diet. No longevity effect of providing pure water in addition to sugar- or methylparaben-supplemented meals was observed. Feeding preference tests were performed to determine whether meals containing methylparaben were preferred, and whether, when given no choice but the less-preferred diet, mosquitoes would consume less sugar. Using the stable carbon isotope (13)C in paired tests, we show that the sugar diet containing methylparaben was clearly avoided by A. gambiae but not A. arabiensis. Little effect of methylparaben on the total amount of sugar consumed was observed when mosquitoes were given no diet choice. Methylparaben effects on Plasmodium cynomolgi B oocyst formation and encapsulation were observed in a normal A. gambiae stock and one which encapsulates at a high frequency. Nearly two-fold increases in the number of both normal and encapsulated oocysts were observed as a result of methylparaben in the diet. Because of its longevity effects, we have implemented methylparaben use for all mosquitoes in our holdings and recommend it as a routine sugar meal supplement. PMID:19041323

  2. Comparison of antimicrobial activity of essential oils, plant extracts and methylparaben in cosmetic emulsions: 2 months study.

    PubMed

    Herman, Anna

    2014-09-01

    The aim of the study was to compare the preservative effectiveness of plant extracts (Matricaria chamomilla, Aloe vera, Calendula officinalis) and essential oils (Lavandulla officinalis, Melaleuca alternifolia, Cinnamomum zeylanicum) with methylparaben in cosmetic emulsions against skin microflora during 2 months of application by volunteers. Cosmetic emulsions with extracts (2.5 %), essential oils (2.5 %), methylparaben (0.4 %) or placebo were tested by 40 volunteers during 2 months of treatment. In order to determine microbial purity of the emulsions, the samples were taken after 0, 2, 4, 6 and 8 weeks of application. Throughout the trial period it was revealed that only cinnamon oil completely inhibited the growth of bacteria, yeast and mould, as compared to all other essential oils, plant extracts and methylparaben in the tested emulsions. This result shows that cinnamon oil could successfully replace the use of methylparaben in cosmetics, at the same time ensuring microbiological purity of a cosmetic product under its in-use and storage conditions. PMID:24891745

  3. IUPAC-NIST Solubility Data Series. 90. Hydroxybenzoic Acid Derivatives in Binary and Ternary Systems. Part II. Hydroxybenzoic Acids, Hydroxybenzoates, and Hydroxybenzoic Acid Salts in Nonaqueous Systems

    NASA Astrophysics Data System (ADS)

    Goto, Ayako; Miyamoto, Hiroshi; Salomon, Mark; Goto, Rensuke; Fukuda, Hiroshi; Königsberger, Erich; Königsberger, Lan-Chi; Scharlin, Pirketta

    2011-06-01

    The solid-liquid solubility data for well defined nonaqueous binary and ternary systems are reviewed. One component includes hydroxybenzoic acid, hydroxybenzoate, and hydroxybenzoic acid salt, and another component includes a variety of organic compounds (hydrocarbons, alcohols, halogenated hydrocarbons, carboxylic acids, esters, et al.) and carbon dioxide. The ternary systems include mixtures of organic substances of various classes and carbon dioxide. The total number of compilation sheets is 270 for six types of system. Almost all data are expressed as mass percent and mole fraction as well as the originally reported units, while some data are expressed as molar concentration. Critical evaluation was carried out for the binary nonaqueous systems of 2-, 3-, and 4-hydroxybenzoic acids and hydroxybenzoates (methylparaben, ethylparaben, propylparaben, and butylparaben) in alcohols, 1-heptane, and benzene.

  4. 21 CFR 181.23 - Antimycotics.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Substances classified as antimycotics, when migrating from food-packaging material shall include: Calcium propionate. Methylparaben (methyl p -hydroxybenzoate). Propylparaben (propyl p -hydroxybenzoate). Sodium benzoate. Sodium...

  5. 21 CFR 181.23 - Antimycotics.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Substances classified as antimycotics, when migrating from food-packaging material shall include: Calcium propionate. Methylparaben (methyl p -hydroxybenzoate). Propylparaben (propyl p -hydroxybenzoate). Sodium benzoate. Sodium...

  6. Bioanalysis of propylparaben and p-hydroxybenzoic acid, and their sulfate conjugates in rat plasma by liquid chromatography-tandem mass spectrometry.

    PubMed

    Zhao, Yue; Liu, Guowen; Shen, Hongwu; Shen, Jim X; Aubry, Anne-Françoise; Sivaraman, Lakshmi; Arnold, Mark E

    2014-02-01

    Two rugged liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods for the determination of propylparaben, its major metabolite, p-hydroxybenzoic acid (pHBA), and their sulfate conjugates have been developed and validated in citric acid-treated rat plasma. To prevent propylparaben being hydrolyzed to pHBA ex vivo, rat plasma was first treated with citric acid; then collected and processed at a reduced temperature (ice bath). Stable isotope labeled internal standards, d4-propylparaben, (13)C6-pHBA, and the d4-labeled internal standards of their sulfate conjugates were used in the methods. The analytes were extracted from the matrix using protein precipitation, followed by chromatographic separation on a Waters ACQUITY UPLC HSS T3 column. Quantification using negative ion electrospray was performed on a Sciex API 4000 mass spectrometer. The analytical ranges were established from 2.00 to 200 ng/mL for propylparaben, 50.0-5000 ng/mL for pHBA, 50.0-10,000 ng/mL for the sulfate conjugate of propylparaben (SPP) and 200-40,000 ng/mL for the sulfate conjugate of pHBA (SHBA). Inter- and intra-run precision for the quality control samples were less than 5.3% and 4.4% for all analytes; and the overall accuracy was within ±5.7% of the nominal values. The validated bioanalytical methods demonstrated excellent sensitivity, specificity, accuracy and precision and were successfully applied to a rat toxicology study under the regulations of Good Laboratory Practices (GLP). Strategies have been developed and applied toward overcoming the challenges related to analyte stability, and environmental and endogenous background. PMID:24412689

  7. Embryonic exposure of medaka (Oryzias latipes) to propylparaben: effects on early development and post-hatching growth.

    PubMed

    González-Doncel, Miguel; García-Mauriño, José Enrique; San Segundo, Laura; Beltrán, Eulalia M; Sastre, Salvador; Fernández Torija, Carlos

    2014-01-01

    Here we proposed a battery of non-invasive biomarkers and a histological survey to examine physiological/anatomical features in embryos, eleutheroembryos (13 days post-fertilization, dpf), and larvae (28-42 dpf) of medaka to investigate the effects of embryonic exposure to propylparaben (PrP). Concentrations <1000 ?g PrP/L didn't exert early or late toxic effects. However, survivorship was affected at 4000 ?g/L in eleutheroembryos and at ?1000 ?g/L in larvae. Histological alterations were found in 37.5% of eleutheroembryos exposed to 4000 ?g PrP/L. Morphometric analysis of the gallbladder revealed significant dilation at ?400 ?g/L throughout embryo development. Ethoxyresorufin-O-deethylase (EROD), as indicator of cytochrome P4501A activity, didn't reveal induction/inhibition although its combination with a P4501A agonist (i.e. ?-naphthoflavone) resulted in a synergic EROD response. Results suggest a low toxicity of PrP for fish and support the use of fish embryos and eleutheroembryos as alternatives of in vivo biomarkers indicative of exposure/toxicity. PMID:24095706

  8. Structural Changes in PEO?PPO?PEO Gels Induced by Methylparaben and Dexamethasone Observed Using Time-Resolved SAXS

    SciTech Connect

    Meznarich, Norman A.K.; Juggernauth, K. Anne; Batzli, Kiersten M.; Love, Brian J. (Michigan)

    2011-11-17

    Aqueous solutions of polyoxyethylene-polyoxypropylene-polyoxyethylene (PEO-PPO-PEO) triblock copolymers (commercially available as Pluronic surfactants) micellize and structurally arrange into cubic quasicrystalline lattices as their temperature is raised. This structural evolution is seen macroscopically as a gelation, and the presence of these ordered phases can be controlled through both polymer concentration and temperature. The presence of added solutes within the dispersions can also affect the onset and kinetics of structure formation. Here we investigate the structures formed in Pluronic F127 solutions ranging from 20 to 30% with two pharmaceutical additives [methylparaben (MP) and dexamethasone (DX)] using small-angle X-ray scattering (SAXS). We observe both the progressive evolution and breakdown of these structures as the temperature is increased from 0 to 80 C. Additionally, we conducted time-resolved SAXS measurements to elucidate the kinetics of the structural evolution. On the basis of the evolution of scattering peaks as the samples were being heated, we suggest that added MP changes the nucleation behavior of fcc phases within the sample from a heterogeneous process to a more homogeneous distribution of nucleated species. MP and DX also stabilize the micelle lattices, allowing them to persevere at higher temperatures. We observed the unusual result that the presence of DX caused the primary peaks of the structure factor to be suppressed, while preserving the higher order peaks. The primary peaks reappeared at the highest temperatures tested.

  9. Determination of biocides in different environmental matrices by use of ultra-high-performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Chen, Zhi-Feng; Ying, Guang-Guo; Lai, Hua-Jie; Chen, Feng; Su, Hao-Chang; Liu, You-Sheng; Peng, Fu-Qiang; Zhao, Jian-Liang

    2012-12-01

    A sensitive and robust method using solid-phase extraction and ultrasonic extraction for preconcentration followed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS-MS) has been developed for determination of 19 biocides: eight azole fungicides (climbazole, clotrimazole, ketoconazole, miconazole, fluconazole, itraconazole, thiabendazole, and carbendazim), two insect repellents (N,N-diethyl-3-methylbenzamide (DEET), and icaridin (also known as picaridin)), three isothiazolinone antifouling agents (1,2-benzisothiazolinone (BIT), 2-n-octyl-4-isothiazolinone (OIT), and 4,5-dichloro-2-n-octyl-isothiazolinone (DCOIT)), four paraben preservatives (methylparaben, ethylparaben, propylparaben, and butylparaben), and two disinfectants (triclosan and triclocarban) in surface water, wastewater, sediment, sludge, and soil. Recovery of the target compounds from surface water, influent, effluent, sediment, sludge, and soil was mostly in the range 70-120%, with corresponding method quantification limits ranging from 0.01 to 0.31 ng L(-1), 0.07 to 7.48 ng L(-1), 0.01 to 3.90 ng L(-1), 0.01 to 0.45 ng g(-1), 0.01 to 6.37 ng g(-1), and 0.01 to 0.73 ng g(-1), respectively. Carbendazim, climbazole, clotrimazole, methylparaben, miconazole, triclocarban, and triclosan were detected at low ng L(-1) (or ng g(-1)) levels in surface water, sediment, and sludge-amended soil. Fifteen target compounds were found in influent samples, at concentrations ranging between 0.4 (thiabendazole) and 372 ng L(-1) (methylparaben). Fifteen target compounds were found in effluent samples, at concentrations ranging between 0.4 (thiabendazole) and 114 ng L(-1) (carbendazim). Ten target compounds were found in dewatered sludge samples, at concentrations ranging between 1.1 (DEET) and 887 ng g(-1) (triclocarban). PMID:23052884

  10. Direct rapid analysis of multiple PPCPs in municipal wastewater using ultrahigh performance liquid chromatography-tandem mass spectrometry without SPE pre-concentration.

    PubMed

    Yu, Ke; Li, Bing; Zhang, Tong

    2012-08-13

    Ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was utilized to develop a rapid, sensitive and reliable method without solid phase extraction (SPE) pre-concentration for trace analysis of 11 pharmaceuticals and personal care products (PPCPs) in in?uent and ef?uent from municipal wastewater treatment plants (WWTPs). This method not only shortened the analysis time but also reduced analysis cost significantly by omitting SPE process and avoiding the consumption of SPE cartridge. Detection parameters for UHPLC-MS/MS analysis were optimized, including sample pH, eluent, mobile phase (solvent and additive), column temperature, and ?ow rate. Under the optimal conditions, all analytes were well separated and detected within 8.0min by UHPLC-MS/MS. The method quantification limits (MQLs) for the 11 PPCPs ranged from 0.040 to 88ngL(-1) and from 0.030 to 90ngL(-1) for influent and effluent, respectively. The matrix effect was systematically investigated and quantified for different types of samples. The analysis of in?uent and ef?uent samples of two WWTPs in Hong Kong revealed the presence of 11 PPCPs, including acyclovir, benzophenone-3, benzylparaben, carbamazepine, ethylparaben, fluconazole, fluoxetine, methylparaben, metronidazole, propylparaben, and ranitidine. Their concentrations ranged from 9.1 to 1810ngL(-1) in influent and from 6.5 to 823ngL(-1) in effluent samples collected from Hong Kong WWTPs. PMID:22790701

  11. Parabens determination in cosmetic and personal care products exploiting a multi-syringe chromatographic (MSC) system and chemiluminescent detection.

    PubMed

    Rodas, Melisa; Portugal, Lindomar A; Avivar, Jessica; Estela, José Manuel; Cerdà, Víctor

    2015-10-01

    Parabens are widely used in dairy products, such as in cosmetics and personal care products. Thus, in this work a multi-syringe chromatographic (MSC) system is proposed for the first time for the determination of four parabens: methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP) in cosmetics and personal care products, as a simpler, practical, and low cost alternative to HPLC methods. Separation was achieved using a 5mm-long precolumn of reversed phase C18 and multi-isocratic separation, i.e. using two consecutive mobile phases, 12:88 acetonitrile:water and 28:72 acetonitrile:water. The use of a multi-syringe buret allowed the easy implementation of chemiluminescent (CL) detection after separation. The chemiluminescent detection is based on the reduction of Ce(IV) by p-hydroxybenzoic acid, product of the acid hydrolysis of parabens, to excite rhodamine 6G (Rho 6G) and measure the resulting light emission. Multivariate designs combined with the concepts of multiple response treatments and desirability functions have been employed to simultaneously optimize and evaluate the responses. The optimized method has proved to be sensitive and precise, obtaining limits of detection between 20 and 40µgL(-1) and RSD <4.9% in all cases. The method was satisfactorily applied to cosmetics and personal care products, obtaining no significant differences at a confidence level of 95% comparing with the HPLC reference method. PMID:26078157

  12. Glucocorticoid-like activity of propylparaben, butylparaben, diethylhexyl phthalate and tetramethrin mixtures studied in the MDA-kb2 cell line.

    PubMed

    Klop?i?, Ivana; Kolšek, Katra; Dolenc, Marija Sollner

    2015-01-22

    Endocrine-disrupting compounds can interfere with the endocrine organs or hormone system and cause tumors, birth defects and developmental disorders in humans. The estrogen-like activity of compounds has been widely studied but little is known concerning their possible modulation of the glucocorticoid receptor. Steroidal (synthetic and natural) and non-steroidal endocrine-active compounds commonly occur as complex mixtures in human environments. Identification of such molecular species, which are responsible for modulating the glucocorticoid receptor are necessary to fully assess their risk. We have used the MDA-kb2 cell line, which expresses endogenous glucocorticoid receptor and a stably transfected luciferase reporter gene construct, to quantify the glucocorticoid-like activity of four compounds present in products in everyday use - propylparaben (PP), butylparaben (BP), diethylhexyl phthalate (DEHP) and tetramethrin (TM). We tested all possible combinations of these compounds at two concentrations (1 ?M and 10 nM) and compared their glucocorticoid-like activity. At the concentration of 1 ?M seven mixtures were identified to have glucocorticoid-like activity except: DEHP+TM, BP+TM, DEHP+PP+TM, BP+PP+TM. At the concentration of 10 nM only three mixtures have glucocorticoid modulatory activity: DEHP+PP, BP+PP, DEHP+BP+PP+TM. Identified glucocorticoid-like activities were between 1.25 and 1.51 fold at the concentration of 1 ?M and between 1.23 and 1.44 fold at the concentration of 10 nM in comparison with the solvent control. Individually BP, PP, and DEHP had glucocorticoid-like activity of 1.60, 1.57 and 1.50 fold over the solvent control at the concentration of 1 ?M. On the other hand PP and DEHP, at the concentration of 10nM, showed no glucocorticoid-like activity, while BP showed 1.44 fold. The assertion that individual glucocorticoid-like compounds do not produce harm because they are present at low, ineffective levels in humans may be irrelevant when we include mixed exposures. This study emphasizes that risk assessment of compounds should take mixture effects into account. PMID:25448277

  13. Determination of parabens in shampoo using high performance liquid chromatography with amperometric detection on a boron-doped diamond electrode.

    PubMed

    Martins, Isarita; Carreira, Franciely Cristiani; Canaes, Larissa S; de Souza Campos Junior, Francisco Alberto; da Silva Cruz, Letícia Maria; Rath, Susanne

    2011-07-15

    Methylparaben (MePa), ethylparaben (EtPa) and propylparaben (PrPa) have been widely used, among others, as chemical preservatives in cosmetics, drugs and foods. As these compounds are linked with allergies, dermatitis and estrogenic properties, it is necessary to control the concentration of these substances in different matrices. The aim of this paper are: to evaluate the electrochemical behavior of parabens on the boron-doped diamond (BDD) electrode and the development of a chromatographic method, with electrochemical detection (HPLC-ED), for determination of parabens in shampoo. A BDD (8000 ppm) electrode was adapted in a thin layer mode analytical cell consisting of a stainless steel and a platinum wire as reference and auxiliary electrodes, respectively. Chromatographic separations were obtained with a reversed phase C8 analytical column and a mobile phase of 0.025 molL(-1) disodium phosphate, pH 7.0, and acetonitrile (40:60, v/v), delivered at a flow rate of 1.0 mL min(-1). Sample preparation was performed by solid phase extraction using C18 cartridges and acetonitrile for elution. Benzylparaben was employed as internal standard. The HPLC-ED method developed, using the BDD electrode, was validated for the determination of parabens in shampoos and presented adequate linearity (>0.999), in the range of 0.0125-0.500% (w/w), detectability 0.01% (w/w), precision (RSD of 2.3-9.8%) and accuracy (93.1-104.4%) and could be applied for routine quality control of shampoos containing MePa, EtPa and PrPa. PMID:21645663

  14. Determination of hormones, a plasticizer, preservatives, perfluoroalkylated compounds, and a flame retardant in water samples by ultrasound-assisted dispersive liquid-liquid microextraction based on the solidification of a floating organic drop.

    PubMed

    Martín, Julia; Santos, Juan Luis; Aparicio, Irene; Alonso, Esteban

    2015-10-01

    Dispersive liquid-liquid microextraction based on the solidification of a floating organic drop (DLLME-SFO) is a novel extraction technique commonly applied for the extraction on a specific group of compounds. In this paper, the applicability of ultrasound-assisted DLLME-SFO for multiresidue extraction has been evaluated. A method for the simultaneous extraction of four hormones (17?-ethinylestradiol, 17?-estradiol, estriol and estrone), a plasticizer (bisphenol A), three preservatives (methyl-, ethyl- and propylparaben), six perfluoroalkylated compounds (perfluorooctane sulfonic acid and five perfluoroalkyl carboxylic acids, from C4 to C8), and a brominated flame retardant (hexabromocyclododecane) has been developed and validated for their extraction from surface water and tap water. Determination was carried out by high-performance liquid chromatography-tandem mass spectrometry in negative ionization mode. Recoveries of the target compounds were highly dependent on their logKow values. Linear relationship between recoveries and logKow values was observed for compounds from the same group (hormones, preservatives and perfluoroalkylated carboxylic acids). The lowest recoveries were obtained for the less hydrophobic compounds (estriol (43%), methylparaben (32%), ethylparaben (45%) and the perfluorinated compounds of shorter alkyl chain (C4: 17%, C5: 41% and C6: 57%)). Recoveries of the other pollutants were higher than 80%. Precision, expressed as relative standard deviation, was in the range from 1% to 16%. Method detection limits were in the range 0.001-1.126µgL(-1), for surface water, and 0.001-1.446µgL(-1) for tap water. No important matrix effect was observed. PMID:26078168

  15. Application and validation of chemometrics-assisted spectrophotometry and liquid chromatography for the simultaneous determination of six-component pharmaceuticals

    Microsoft Academic Search

    Alaa El-Gindy; Samy Emara; Ahmed Mostafa

    2006-01-01

    Three methods are developed for the simultaneous determination of theophylline anhydrous (TH), guaiphenesin (GP), diphenhydramine hydrochloride (DP), methylparaben (MP), propylparaben (PP) and sodium benzoate (BZ) in pharmaceutical syrup. The chromatographic method depends on a high performance liquid chromatographic separation on a reversed-phase C18 column at ambient temperature with mobile phase consisting of 25mM KH2PO4, pH 3.2—acetonitrile (60:40, v\\/v). Quantitation was

  16. Advantages of application of UPLC in pharmaceutical analysis.

    PubMed

    Nováková, Lucie; Matysová, Ludmila; Solich, Petr

    2006-01-15

    Ultra Performance Liquid Chromatography (UPLC) is a relatively new technique giving new possibilities in liquid chromatography, especially concerning decrease of time and solvent consumption. UPLC chromatographic system is designed in a special way to withstand high system back-pressures. Special analytical columns UPLC Acquity UPLC BEH C(18) packed with 1.7 microm particles are used in connection with this system. The quality control analyses of four pharmaceutical formulations were transferred from HPLC to UPLC system. The results are compared for Triamcinolon cream containing trimacinolone acetonide, methylparaben, propylparaben and triamcinolone as degradation product, for Hydrocortison cream (hydrocortisone acetate, methylparaben, propylparaben and hydrocortisone degradation product), for Indomethacin gel (indomethacin and its degradation products 4-chlorobenzoic acid and 5-methoxy-2-methylindoleacetic acid) and for Estrogel gel (estradiol, methylparaben, propylparaben and estrone as degradation product). The UPLC system allows shortening analysis time up to nine times comparing to the conventional system using 5 microm particle packed analytical columns. In comparison with 3 microm particle packed analytical columns analysis should be shortened about three times. The negative effect of particle decrease is back-pressure increase about nine times (versus 5 microm) or three times (versus 3 microm), respectively. The separation on UPLC is performed under very high pressures (up to 100MPa is possible in UPLC system), but it has no negative influence on analytical column or other components of chromatographic system. Separation efficiency remains maintained or is even improved. Differences and SST parameters, advantages and disadvantages of UPLC are discussed. PMID:18970409

  17. Exposure determinants of phthalates, parabens, bisphenol A and triclosan in Swedish mothers and their children

    PubMed Central

    Larsson, Kristin; Ljung Björklund, Karin; Palm, Brita; Wennberg, Maria; Kaj, Lennart; Lindh, Christian H.; Jönsson, Bo A.G.; Berglund, Marika

    2014-01-01

    Chemicals such as phthalates, parabens, bisphenol A (BPA) and triclosan (TCS), used in a wide variety of consumer products, are suspected endocrine disrupters although their level of toxicity is thought to be low. Combined exposure may occur through ingestion, inhalation and dermal exposure, and their toxic as well as combined effects are poorly understood. The objective of the study was to estimate the exposure to these chemicals in Swedish mothers and their children (6–11 years old) and investigate potential predictors of the exposure. Urine samples from 98 mother–child couples living in either a rural or an urban area were analyzed for the concentrations of four metabolites of di-(2-ethylhexyl) phthalate (DEHP), three metabolites of di-iso-nonyl phthalate (DiNP), mono-ethyl phthalate (MEP), mono-benzyl phthalate (MBzP) and mono-n-butyl phthalate (MnBP), methylparaben (MetP), ethylparaben (EthP), propylparaben (ProP), butylparaben, benzylparaben, BPA, and TCS. Information on sociodemographics, food consumption habits and use of personal care products, obtained via a questionnaire, was used to investigate the associations between the urinary levels of chemicals and potential exposure factors. There were fairly good correlations of biomarker levels between the mothers and their children. The children had generally higher levels of phthalates (geometric mean ?DEHP 65.5 ?g/L; ?DiNP 37.8 ?g/L; MBzP 19.9 ?g/L; MnBP 76.9 ?g/L) than the mothers (?DEHP 38.4 ?g/L; ?DiNP 33.8 ?g/L; MBzP 12.8 ?g/L; MnBP 63.0 ?g/L). Conversely, the mother's levels of parabens (MetP 37.8 ?g/L; ProP 13.9 ?g/L) and MEP (43.4 ?g/L) were higher than the children's levels of parabens (MetP 6.8 ?g/L; ProP 2.1 ?g/L) and MEP (28.8 ?g/L). The urinary levels of low molecular weight phthalates were higher among mothers and children in the rural area (MBzP p = < 0.001; MnBP p = 0.001–0.002), which is probably due to higher presence of PVC in floorings and wall coverings in this area, whereas the levels of parabens were higher among the children in the urban area (MetP p = 0.003; ProP p = 0.004) than in the rural area. The levels of high molecular weight phthalates were associated with consumption of certain foods (i.e. chocolate and ice cream) whereas the levels of parabens were associated with use of cosmetics and personal care products. PMID:25216151

  18. Occurrence and analysis of parabens in municipal sewage sludge from wastewater treatment plants in Madrid (Spain).

    PubMed

    Albero, Beatriz; Pérez, Rosa Ana; Sánchez-Brunete, Consuelo; Tadeo, José Luis

    2012-11-15

    A rapid method for determination of seven parabens and two chlorinated by-products in sewage sludge was developed based on matrix solid-phase dispersion and gas chromatography-tandem mass spectrometry. The analytical procedure showed good recoveries that ranged from 80 to 125%, with relative standard deviations lower than 12% and low detection limits, ranging from 0.1 to 2.0 ng g(-1) dry weight. The developed method was applied to the analysis of sewage sludge collected during 2010 in 19 wastewater treatment plants (WWTPs) located in various urban, industrial or rural zones in Madrid (Spain). Methylparaben was found in most of the WWTPs sampled (95%) at levels between 5.1 and 26.2 ng g(-1) dry weight and propylparaben was detected in 74% of the WWTPs at levels up to 44.1 ng g(-1) dry weight. In order to study the temporal variation of parabens and two chlorinated parabens during a four-year period, sludge samples were collected from 3 selected WWTPs. The levels of methylparaben encountered were rather constant throughout the sampling period whereas propylparaben levels slightly increased. In one of the WWTPs monitored, isopropylparaben was found at the beginning of the sampling period but its content decreased and was not detected in the 2010 sampling. PMID:22640822

  19. Surfactant and temperature effects on paraben transport through silicone membranes.

    PubMed

    Waters, Laura J; Dennis, Laura; Bibi, Aisha; Mitchell, John C

    2013-08-01

    This study investigates the effects of two surfactants (one anionic and one non-ionic) and controlled modifications in temperature (298-323K) on the permeation of two structurally similar compounds through a silicone membrane using a Franz diffusion cell system. In all cases the presence of an anionic surfactant, namely sodium dodecyl sulphate (SDS), reduced the permeation of both compounds (methylparaben and ethylparaben) over a period of 24h. The degree of permeation reduction was proportional to the concentration of surfactant with a maximum effect observed, with an average reduction of approximately 50%, at the highest surfactant concentration of 20mM. Differences were seen around the critical micelle concentration (CMC) of SDS implying the effect was partially connected with the favoured formation of micelles. In contrast, the presence of non-ionic surfactant (Brij 35) had no effect on the permeation of methylparaben or ethylparaben at any of the concentrations investigated, both above and below the CMC of the surfactant. From these findings the authors conclude that the specific effects of SDS are a consequence of ionic surfactant-silicone interactions retarding the movement of paraben through the membrane through indirect modifications to the surface of the membrane. As expected, an increase in experimental temperature appeared to enhance the permeation of both model compounds, a finding that is in agreement with previously reported data. Interestingly, in the majority of cases this effect was optimum at the second highest temperature studied (45°C) which suggests that permeation is a temperature-dependent phenomenon. PMID:23511625

  20. Occurrence of preservatives and antimicrobials in Japanese rivers.

    PubMed

    Kimura, Kumiko; Kameda, Yutaka; Yamamoto, Hiroshi; Nakada, Norihide; Tamura, Ikumi; Miyazaki, Motonobu; Masunaga, Shigeki

    2014-07-01

    We established a method for the simultaneous analysis of seven preservatives and five antimicrobials in water. These chemicals are widely used in cosmetics, and their presence in river water is of concern. We used the method to test 13 sites in Japanese rivers and streams contaminated by domestic wastewater, effluent, or industrial wastewater. 2-Phenoxyethanol (2-PE), isopropylmethylphenol, resorcinol, and triclosan were detected at most sites; the maximum concentration of 2-PE detected was 14000 ng L(-1). The results suggest that the major sources of 2-PE were cosmetics and household detergents. The ratio of methylparaben to n-propylparaben in river waters with direct wastewater drainage was similar to that in common cosmetics. This is the first research on levels of 2-PE, isopropylmethylphenol, and chlorphenesin in river water. PMID:24556546

  1. Advantages of pentafluorophenylpropyl stationary phase over conventional C18 stationary phase--application to analysis of triamcinolone acetonide.

    PubMed

    Havlíková, Lucie; Matysová, Ludmila; Hájková, Renata; Satínský, Dalibor; Solich, Petr

    2008-07-30

    A pentafluorophenylpropyl (PFPP) stationary phase was for the first time tested for the simultaneous determination of triamcinolone acetonide, its degradation product triamcinolone and two preservatives, methylparaben, and propylparaben. A new simple isocratic reversed phase HPLC method with UV detection, using estradiol hemihydrate as an internal standard, has been developed and validated. Chromatography was performed on a Discovery HS F5 column (150 mm x 4.6 mm, 5 microm) using a binary mobile phase composed of acetonitrile and water 45:55 (v:v). The flow-rate was 0.6 mL/min, the column temperature 25 degrees C and the UV detection was accomplished at 240 nm. The chromatography results using PFPP stationary phase were compared with those obtained using conventional C18 columns. PMID:18585326

  2. Resolution of five-component mixture using mean centering ratio and inverse least squares chemometrics

    PubMed Central

    2013-01-01

    Background A comparative study of the use of mean centering of ratio spectra and inverse least squares for the resolution of paracetamol, methylparaben, propylparaben, chlorpheniramine maleate and pseudoephedrine hydrochloride has been achieved showing that the two chemometric methods provide a good example of the high resolving power of these techniques. Method (I) is the mean centering of ratio spectra which depends on using the mean centered ratio spectra in four successive steps that eliminates the derivative steps and therefore the signal to noise ratio is improved. The absorption spectra of prepared solutions were measured in the range of 220–280 nm. Method (II) is based on the inverse least squares that depend on updating developed multivariate calibration model. The absorption spectra of the prepared mixtures in the range 230–270 nm were recorded. Results The linear concentration ranges were 0–25.6, 0–15.0, 0–15.0, 0–45.0 and 0–100.0 ?g mL-1 for paracetamol, methylparaben, propylparaben, chlorpheniramine maleate and pseudoephedrine hydrochloride, respectively. The mean recoveries for simultaneous determination were between 99.9-101.3% for the two methods. The two developed methods have been successfully used for prediction of five-component mixture in Decamol Flu syrup with good selectivity, high sensitivity and extremely low detection limit. Conclusion No published method has been reported for simultaneous determination of the five components of this mixture so that the results of the mean centering of ratio spectra method were compared with those of the proposed inverse least squares method. Statistical comparison was performed using t-test and F-ratio at P?=?0.05. There was no significant difference between the results. PMID:24028626

  3. Occurrence of acidic pharmaceuticals and personal care products in Turia River Basin: from waste to drinking water.

    PubMed

    Carmona, Eric; Andreu, Vicente; Picó, Yolanda

    2014-06-15

    The occurrence of 21 acidic pharmaceuticals, including illicit drugs, and personal care products (PPCPs) in waste, surface and drinking water and in sediments of the Turia River Basin (Valencia, Spain) was studied. A liquid chromatography tandem mass spectrometry (LC-MS/MS) method was developed for the determination of these PPCPs with electrospray (ESI) in negative ionization (NI) mode. Ammonium fluoride in the mobile phase improved ionization efficiency by an average increase in peak area of 5 compared to ammonium formate or formic acid. All studied compounds were detected and their concentration was waste water>surface water>drinking water. PPCPs were in waste water treatment plants (WWTPs) influents up to 7.26?gL(-1), dominated by ibuprofen, naproxen and 11-nor-9-carboxy-?9-tetrahydrocannabinol (THCOOH). WWTPs were highly effective in removing most of them, with an average removal rate of >90%. PPCPs were still detected in effluents in the 6.72-940ngL(-1) range, with the THCOOH, triclocarban, gemfibrozil and diclofenac as most prevalent. Similarly, diclofenac, gemfibrozil, ibuprofen, naproxen and propylparaben were detected quite frequently from the low ngL(-1) range to 7?gL(-1) in the surface waters of Turia River. Ibuprofen, methylparaben, salicylic acid and tetrahydrocannabinol (THC) were at concentrations up to 0.85ngg(-1) d.w. in sediments. The discharge of WWTP as well as of non-treated waters to this river is a likely explanation for the significant amount of PPCPs detected in surface waters and sediments. Mineral and tap waters also presented significant amounts (approx. 100ngL(-1)) of ibuprofen, naproxen, propylparaben and butylparaben. The occurrence at trace levels of several PPCPs in drinking water raises concerns about possible implications for human health. PMID:24686145

  4. New sorbent in the dispersive solid phase extraction step of quick, easy, cheap, effective, rugged, and safe for the extraction of organic contaminants in drinking water treatment sludge.

    PubMed

    Cerqueira, Maristela B R; Caldas, Sergiane S; Primel, Ednei G

    2014-04-01

    Recent studies have shown a decrease in the concentration of pesticides, pharmaceuticals and personal care products (PCPs) in water after treatment. A possible explanation for this phenomenon is that these compounds may adhere to the sludge; however, investigation of these compounds in drinking water treatment sludge has been scarce. The sludge generated by drinking water treatment plants during flocculation and decantation steps should get some special attention not only because it has been classified as non-inert waste but also because it is a very complex matrix, consisting essentially of inorganic (sand, argil and silt) and organic (humic substances) compounds. In the first step of this study, three QuEChERS methods were used, and then compared, for the extraction of pesticides (atrazine, simazine, clomazone and tebuconazole), pharmaceuticals (amitriptyline, caffeine, diclofenac and ibuprofen) and PCPs (methylparaben, propylparaben, triclocarban and bisphenol A) from drinking water treatment sludge. Afterwards, the study of different sorbents in the dispersive solid phase extraction (d-SPE) step was evaluated. Finally, a new QuEChERS method employing chitin, obtained from shrimp shell waste, was performed in the d-SPE step. After having been optimized, the method showed limits of quantification (LOQ) between 1 and 50 ?g kg(-1) and the analytical curves showed r values higher than 0.98, when liquid chromatography tandem mass spectrometry was employed. Recoveries ranged between 50 and 120% with RSD?15%. The matrix effect was evaluated and compensated with matrix-matched calibration. The method was applied to drinking water treatment sludge samples and methylparaben and tebuconazole were found in concentration

  5. Electrochemical conversion of micropollutants in gray water.

    PubMed

    Butkovskyi, Andrii; Jeremiasse, Adriaan W; Hernandez Leal, Lucia; van der Zande, Ton; Rijnaarts, Huub; Zeeman, Grietje

    2014-02-01

    Electrochemical conversion of micropollutants in real gray water effluent was studied for the first time. Six compounds that are frequently found in personal care and household products, namely methylparaben, propylparaben, bisphenol A, triclosan, galaxolide, and 4- methylbenzilidene camphor (4-MBC), were analyzed in the effluent of the aerobic gray water treatment system in full operation. The effluent was used for lab-scale experiments with an electrochemical cell operated in batch mode. Three different anodes and five different cathodes have been tested. Among the anodes, Ru/Ir mixed metal oxide showed the best performance. Ag and Pt cathodes worked slightly better than Ti and mixed metal oxide cathodes. The compounds that contain a phenolic ring (parabens, bisphenol A, and triclosan) were completely transformed on this anode at a specific electric charge Q = 0.03 Ah/L. The compounds, which contain a benzene ring and multiple side methyl methyl groups (galaxolide, 4-MBC) required high energy input (Q ? 0.6 Ah/L) for transformation. Concentrations of adsorbable organohalogens (AOX) in the gray water effluent increased significantly upon treatment for all electrode combinations tested. Oxidation of gray water on mixed metal oxide anodes could not be recommended as a post-treatment step for gray water treatment according to the results of this study. Possible solutions to overcome disadvantages revealed within this study are proposed. PMID:24364736

  6. A Rapid, Stability Indicating RP-UPLC Method for Simultaneous Determination of Ambroxol Hydrochloride, Cetirizine Hydrochloride and Antimicrobial Preservatives in Liquid Pharmaceutical Formulation

    PubMed Central

    Trivedi, Rakshit Kanubhai; Patel, Mukesh C.; Jadhav, Sushant B.

    2011-01-01

    A stability indicating reversed phase ultra performance liquid chromatography (RP-UPLC) method was developed for simultaneous determination of ambroxol hydrochloride (AMB), cetirizine hydrochloride (CTZ), methylparaben (MP) and propylparaben (PP) in liquid pharmaceutical formulation. The desired chromatographic separation was achieved on an Agilent Eclipse plus C18, 1.8 ?m (50 × 2.1 mm) column using gradient elution at 237 nm detector wavelength. The optimized mobile phase consists of a mixture of 0.01 M phosphate buffer and 0.1 % triethylamine as a solvent-A and acetonitrile as a solvent-B. The developed method separates AMB, CTZ, MP and PP in presence of twelve known impurities/degradation products and one unknown degradation product within 3.5 min. Stability indicating capability was established by forced degradation experiments and seperation of known and unknown degradation products. The lower limit of quantification was established for AMB, CTZ, MP and PP. The developed RP-UPLC method was validated according to the International Conference on Harmonization (ICH) guidelines. This validated method is applied for simultaneous estimation of AMB, CTZ, MP and PP in commercially available syrup samples. Further, the method can be extended for estimation of AMB, CTZ, MP, PP and levo-cetirizine (LCTZ) in various commercially available dosage forms. PMID:21886901

  7. High performance liquid chromatographic determination of oxeladin citrate and oxybutynin hydrochloride and their degradation products.

    PubMed

    El-Gindy, Alaa

    2005-08-01

    Two high performance liquid chromatographic (HPLC) methods are presented for the determination of oxeladin citrate (OL) and oxybutynin hydrochloride (OB) and their degradation products. The first method was based on HPLC separation of OL from its degradation product using a Nucleosil C(18) column with a mobile phase consisting of acetonitrile -0.1% phosphoric acid (60:40 v/v). The second method was based on HPLC separation of OB from its degradation product using a VP-ODS C(18) column with a mobile phase consisting of acetonitrile/0.01 M potassium dihydrogen phosphate/diethylamine (60:40:0.2). Quantitation was achieved with UV detection at 220 nm based on peak area. The two HPLC methods were applied for the determination of OL or OB, their degradation products, methylparaben and propylparaben in pharmaceutical preparations. The proposed methods were used to investigate the kinetics of acidic and alkaline degradation processes of OL and OB at different temperatures and the apparent pseudofirst-order rate constant, half-life and activation energy were calculated. The pH-rate profiles of degradation of OL and OB in Britton-Robinson buffer solutions within the pH range 2-12 were studied. PMID:16023117

  8. In vitro induction of apoptosis, necrosis and genotoxicity by cosmetic preservatives: application of flow cytometry as a complementary analysis by NRU.

    PubMed

    Carvalho, C M de; Menezes, P F C; Letenski, G C; Praes, C E O; Feferman, I H S; Lorencini, M

    2012-04-01

    Preservatives are used in cosmetics to prevent microbial contamination; however, some preservatives are not free of allergenic and cytotoxic potential. Allergenicity and cytotoxicity potential values are major aspects of preservative safety, which determine limitations and maximum concentration dose in a cosmetic product. The purpose of this study was to investigate and compare the in vitro apoptosis, necrosis and genotoxicity-inducing potential of five different types of preservatives: Phenoxyethanol (PE), Propylparaben (PP), Methylparaben (MP), Benzyl Alcohol (BA) and Ethylhexyl Glycerine (EG). In vitro experiments were carried out on human dermal fibroblasts by a quantitative flow cytometry method, using specific cell markers (Annexin V, Propidium Iodide and H2AX). We compared the resulting cell viability by means of neutral red uptake (NRU) and established the IC(50) . Our results showed that PE, PP, MP and BA have similar cytotoxic mechanisms (high apoptosis and necrosis levels only at the test concentration of 1%), whereas EG showed only an apoptosis pathway. For genotoxicity, both parabens yielded the highest values. Results obtained by flow cytometry for necrosis were comparable to those produced by NRU; however, NRU does not distinguish apoptosis from necrosis. We propose that flow cytometry is a more sophisticated methodology for understanding the cytotoxic mechanisms of cosmetic preservatives and can be used to complement the NRU. PMID:22118339

  9. Antimicrobial preservative use in parenteral products: past and present.

    PubMed

    Meyer, Brian K; Ni, Alex; Hu, Binghua; Shi, Li

    2007-12-01

    The following review provides a comprehensive summary of antimicrobial preservatives that are commonly used in licensed parenteral products to date. The information reviewed includes the general properties of the preservatives, the doses and frequency of their use, the classes of the preserved products (peptide, protein, vaccine, and small molecule products), the interactions with other formulation components, and the criteria commonly used for their selection in parental product formulations. It was revealed that phenol and benzyl alcohol are the two most common antimicrobial preservatives used in peptide and protein products, while phenoxyethanol is the most frequently used preservative in vaccines. Benzyl alcohol or a combination of methylparaben and propylparaben are generally found in small molecule parenteral formulations. The key criteria for antimicrobial preservative selection are the preservative's dose, antimicrobial functionality, and effect on the active ingredient. Additionally, the use of spectroscopic techniques (circular dicroism (CD) and fluorescence) and differential scanning calorimetry (DSC) were identified as common techniques used in evaluating an antimicrobial preservative for its impact on the conformational stability of peptide, protein, and vaccine antigens. The future use of preservatives is also discussed, including antimicrobial agents such as peptides, and regulatory requirements for antimicrobial effectiveness testing. PMID:17722087

  10. Reversed-phase porous silica rods, an alternative approach to high-performance liquid chromatographic separation using the sequential injection chromatography technique.

    PubMed

    Satínský, Dalibor; Huclová, Jitka; Solich, Petr; Karlícek, Rolf

    2003-10-10

    A commercially available porous silica rod column was used as a separation tool for the sequential injection analysis (SIA). A porous solid monolithic column showed high performance at a low pressure, allowing sequential injection analysis to be used for the first time for separation in HPLC fashion. In this contribution, we tried to demonstrate a new separation concept with SIA manifold for the simultaneous determination of four different compounds (methylparaben (MP), propylparaben (PP), triamcinolone acetonide (TCA) and internal standard ketoprofen (KP)) in a pharmaceutical triamcinolon cream 0.1% formulation. A Chromolith Flash RP-18e, 25 mm x 4.6 mm column with a 10 mm pre-column (Merck, Germany) and a FIAlab 3000 system (USA) with an 8-port selection valve and 10 ml syringe were used for sequential injection chromatographic separations in our study. The mobile phase used was acetonitrile-methanol-water (35:5:65, v/v/v) + 0.05% nonylamine, pH 2.5, flow rate 0.6 ml min(-1). The analysis time was <6 min. A novel sequential injection chromatography (SIC) technique with UV spectrophotometric detection was optimised and validated. PMID:14570335

  11. Evaluating food additives as antifungal agents against Monilinia fructicola in vitro and in hydroxypropyl methylcellulose-lipid composite edible coatings for plums.

    PubMed

    Karaca, Hakan; Pérez-Gago, María B; Taberner, Verònica; Palou, Lluís

    2014-06-01

    Common food preservative agents were evaluated in in vitro tests for their antifungal activity against Monilinia fructicola, the most economically important pathogen causing postharvest disease of stone fruits. Radial mycelial growth was measured in Petri dishes of PDA amended with three different concentrations of the agents (0.01-0.2%, v/v) after 7 days of incubation at 25 °C. Thirteen out of fifteen agents tested completely inhibited the radial growth of the fungus at various concentrations. Among them, ammonium carbonate, ammonium bicarbonate and sodium bicarbonate were the most effective while sodium acetate and sodium formate were the least effective. The effective agents and concentrations were tested as ingredients of hydroxypropyl methylcellulose (HPMC)-lipid edible coatings against brown rot disease on plums previously inoculated with M. fructicola (curative activity). 'Friar' and 'Larry Ann' plums were inoculated with the pathogen, coated with stable edible coatings about 24h later, and incubated at 20 °C and 90% RH. Disease incidence (%) and severity (lesion diameter) were determined after 4, 6, and 8 days of incubation and the 'area under the disease progress stairs' (AUDPS) was calculated. Coatings containing bicarbonates and parabens significantly reduced brown rot incidence in plums, but potassium sorbate, used at 1.0% in the coating formulation, was the most effective agent with a reduction rate of 28.6%. All the tested coatings reduced disease severity to some extent, but coatings containing 0.1% sodium methylparaben or sodium ethylparaben or 0.2% ammonium carbonate or ammonium bicarbonate were superior to the rest, with reduction rates of 45-50%. Overall, the results showed that most of the agents tested in this study had significant antimicrobial activity against M. fructicola and the application of selected antifungal edible coatings is a promising alternative for the control of postharvest brown rot in plums. PMID:24742996

  12. beta-D(+) glucose-glucose oxidase-catalase for use as an antioxidant system.

    PubMed

    Uppoor, R; Niebergall, P J

    1996-07-01

    The purpose of this study was to investigate the use of beta-D(+) glucose-glucose oxidase (EC 1.1.3.4)-catalase (EC 1.11.1.6) (BDG-GO-CAT) as a new antioxidant system in solutions. A novel method for estimation of activity of the system was developed using a dissolved oxygen (DO) meter and an oxygen probe. The method can be used to determine the enzymatic activity of the system at GO concentrations of 0.005 to 0.030 unit/ml, with an r2 of 0.995 for the linearity of the standard curve, and can be adapted for analysis in any solution. At room temperature of 23.0 degrees +/- 2.0 degrees C, the maximum activity of the BDG-GO-CAT system was found to occur at pH 5.40. The half-life values for the stability of GO-CAT in 0.10 M phosphate buffer solutions of pH 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, and 10.0 were 9.78, 49.43, 53.46, 36.51, 12.68, 1.84, and 0.80 weeks, respectively. Dextrose was used in place of beta-D(+) glucose for cost-saving purposes, and a standard curve for the activity of GO-CAT was obtained using 20 mg/ml dextrose. The BDG-GO-CAT was effective as a DO-scavenger in closed containers, when the containers were opened and exposed to atmosphere for 2 days between tests, and upon reclosing them. Pharmaceutical excipients such as ethanol, glycerin, propylene glycol, methylparaben, propylparaben, artificial strawberry flavor, and sodium benzoate did not show any adverse effect on the activity of BDG-GO-CAT. Sorbitol, high-fructose corn syrup, sucrose, and polyethylene glycol 3350 increased the rate of DO removal. Sodium carboxymethyl-cellulose (CMC) at 2.0% w/v decreased the rate of DO removal. These studies indicate that the BDG(dextrose)-GO-CAT system warrants serious consideration for use an antioxidant system in aqueous formulations. PMID:9552339

  13. Chronic toxicity of parabens and their chlorinated by-products in Ceriodaphnia dubia.

    PubMed

    Terasaki, Masanori; Abe, Ryoko; Makino, Masakazu; Tatarazako, Norihisa

    2015-05-01

    The chronic toxicity of 12 compounds of parabens and their chlorinated by-products was investigated using 7-day Ceriodaphnia dubia test under static renewal condition in order to generate information on how to disinfect by-products of preservatives that are discharged in aquatic systems. The mortality and inhibition of reproduction tended to increase with increasing hydrophobicity and decreased with the degree of chlorination of parabens. The EC50 values for mortality, offspring number, and first brood production ranged between 0.30-3.1, 0.047-12, and 1.3-6.3 mg L(-1) , respectively. For the number of neonates, the most sensitive endpoint, the no-observed-effect concentration (NOEC) and lowest-observed-effect concentration (LOEC) values ranged from 0.63 to 10 mg L(-1) and from 1.2 to 19 mg L(-1) , respectively. Methylparaben (MP), benzylparaben (BnP), and dichlorinated BnP (Cl2 BnP) elicited a significant decrease in offspring numbers even at their lowest concentration tested; the NOEC for these compounds was determined to be less than the lowest test concentration (1.3, 0.04, and 0.63 mg L(-1) for MP, BnP, and Cl2 BnP, respectively). Propylparaben (PP), chlorinated PP, isopropylparaben (iPP), and chlorinated iPP exhibited nonmonotonic concentration-dependent response; their NOEC and LOEC values could not be determined. The multivariate approach involving principal component analysis and hierarchical cluster analysis revealed four groups that corresponded to the toxicological profiles of parabens. Our results suggested that disinfection of parabens by chlorination could reduce aquatic toxicity of original compounds. The findings obtained in our study together with the data available on paraben concentrations in aquatic systems can be used to perform preliminary risk assessment by comparing the predicted environmental concentration (PEC) with the predicted no-effect concentration (PNEC) for the marine aquatic environment. The calculated PEC/PNEC ratios ranged from 0.0012 to 0.2, with the highest value observed in MP. This suggested that there are negligible environmental risks for aquatic organisms at current use levels. © 2013 Wiley Periodicals, Inc. Environ Toxicol 30: 664-673, 2015. PMID:24376163

  14. 21 CFR 181.23 - Antimycotics.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...migrating from food-packaging material shall include: Calcium propionate. Methylparaben (methyl p -hydroxybenzoate...hydroxybenzoate). Sodium benzoate. Sodium propionate. Sorbic acid. [42 FR 14638, Mar. 15,...

  15. 21 CFR 181.23 - Antimycotics.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...migrating from food-packaging material shall include: Calcium propionate. Methylparaben (methyl p -hydroxybenzoate...hydroxybenzoate). Sodium benzoate. Sodium propionate. Sorbic acid. [42 FR 14638, Mar. 15,...

  16. 21 CFR 181.23 - Antimycotics.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...migrating from food-packaging material shall include: Calcium propionate. Methylparaben (methyl p -hydroxybenzoate...hydroxybenzoate). Sodium benzoate. Sodium propionate. Sorbic acid. [42 FR 14638, Mar. 15,...

  17. 9 CFR 424.23 - Prohibited uses.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...part 319 of this subchapter. (3) Sorbic acid, calcium sorbate, sodium sorbate, and other salts of...propylparaben (propyl p-hydroxybenzoate), and calcium propionate, may be used in or on any product, only as...

  18. 77 FR 50462 - Foreign-Trade Zone 59-Lincoln, NE, Notification of Proposed Production Activity; Novartis...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-21

    ...microcrystalline cellulose; inulin; aloe vera gel; carrageenan (viscarin GP109F); wheat dextrin; insulin; benzyl alcohol NF; camphor USP; synthetic; anhydrous citric acid USP/EP find grain; butylparaben NF; methylparaben NF; diphenhydramine...

  19. Essential oils and herbal extracts as antimicrobial agents in cosmetic emulsion.

    PubMed

    Herman, Anna; Herman, Andrzej Przemys?aw; Domagalska, Beata Wanda; M?ynarczyk, Andrzej

    2013-06-01

    The cosmetic industry adapts to the needs of consumers seeking to limit the use of preservatives and develop of preservative-free or self-preserving cosmetics, where preservatives are replaced by raw materials of plant origin. The aim of study was a comparison of the antimicrobial activity of extracts (Matricaria chamomilla, Aloe vera, Calendula officinalis) and essential oils (Lavandulla officinallis, Melaleuca alternifolia, Cinnamomum zeylanicum) with methylparaben. Extracts (2.5 %), essential oils (2.5 %) and methylparaben (0.4 %) were tested against Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, Candida albicans ATCC 14053. Essentials oils showed higher inhibitory activity against tested microorganism strain than extracts and methylparaben. Depending on tested microorganism strain, all tested extracts and essential oils show antimicrobial activity 0.8-1.7 and 1-3.5 times stronger than methylparaben, respectively. This shows that tested extracts and essential oils could replace use of methylparaben, at the same time giving a guarantee of microbiological purity of the cosmetic under its use and storage. PMID:24426114

  20. Photodegradation of parabens by Fe(III)-citrate complexes at circumneutral pH: matrix effect and reaction mechanism.

    PubMed

    Feng, Xiaonan; Chen, Yong; Fang, Yuan; Wang, Xiaoyue; Wang, Zongping; Tao, Tao; Zuo, Yuegang

    2014-02-15

    The photodegradation of four parabens including methyl-, ethyl-, propyl-, and butyl-paraben in the presence of Fe(III)-citrate complexes under simulated sunlight was investigated. The degradation of parabens increased with decreasing pH within the range of 5.0-8.0 at the Fe(III)-to-citrate ratio of 10:150 (?M). The addition of low-molecular-weight carboxylic acids showed different effects on the photodegradation of methylparaben. The low-photoreactive carboxylic acids inhibited the photodegradation of methylparaben in the order of formic acid>succinic acid>acetic acid>malonic acid. In contrast, oxalic acid enhanced the photodegradation and exhibited appreciable synergistic effect with Fe(III)-citrate at concentration higher than 500 ?M. Up to 99.0% of substrate was degraded after 30 min at pH6.0 in the Fe(III)-citrate-oxalate system. The various fractions of fulvic acid inhibited the photodegradation of methylparaben. The inhibition increased with increasing nominal molecular weight of fractionated fulvic acid. Moreover, the photodegradation of methylparaben was inhibited in natural waters in the order of Liangzi Lakemethylparaben were identified by GC-MS analyses and the degradation pathway was proposed. PMID:24291138

  1. Antimicrobial lubricant formulations containing poly(hydroxybenzene)-trimethoprim conjugates synthesized by tyrosinase.

    PubMed

    Gonçalves, Idalina; Botelho, Cláudia M; Teixeira, Ana; Abreu, Ana S; Hilliou, Loïc; Silva, Carla; Cavaco-Paulo, Artur

    2015-05-01

    Poly(hydroxybenzene)-trimethoprim conjugates were prepared using methylparaben as substrate of the oxidative enzyme tyrosinase. MALDI-TOF MS analysis showed that the enzymatic oxidation of methylparaben alone leads to the poly(hydroxybenzene) formation. In the presence of trimethoprim, the methylparaben tyrosinase oxidation leads poly(hydroxybenzene)-trimethoprim conjugates. All of these compounds were incorporated into lubricant hydroxyethyl cellulose/glycerol mixtures. Poly(hydroxybenzene)-trimethoprim conjugates were the most effective phenolic structures against the bacterial growth reducing by 96 and 97% of Escherichia coli and Staphylococcus epidermidis suspensions, respectively (after 24 h). A novel enzymatic strategy to produce antimicrobial poly(hydroxybenzene)-antibiotic conjugates is proposed here for a wide range of applications on the biomedical field. PMID:25761624

  2. Simultaneous determination of some water-soluble vitamins and preservatives in multivitamin syrup by validated stability-indicating high-performance liquid chromatography method

    Microsoft Academic Search

    Stojanka Vidovi?; Biljana Stojanovi?; Jelena Veljkovi?; Ljiljana Praži?-Arsi?; Goran Rogli?; Dragan Manojlovi?

    2008-01-01

    HPLC stability-indicating method has been developed for the simultaneous determination of some water-soluble vitamins (ascorbic acid, thiamine hydrochloride, riboflavin-5?-phosphate sodium, pyridoxine hydrochloride, nicotinamide, d(+)-panthenol) and two preservatives (methylparaben and sodium benzoate) in multivitamin syrup preparation. Water-soluble vitamins, preservatives and their degradants were separated on Zorbax SB-Aq (C18) (250mm×4.6mm, 5?m) column at an ambient temperature. Combined isocratic and gradient elution was

  3. Determination of preservatives in cosmetics, cleaning agents and pharmaceuticals using fast liquid chromatography.

    PubMed

    Baranowska, Irena; Wojciechowska, Iwona; Solarz, Natalia; Krutysza, Ewa

    2014-01-01

    This paper reports the development of a method for simultaneously determining five preservatives in cosmetics, cleaning agents and pharmaceuticals by fast liquid chromatography. Methylisothiazolinone, methylchloroisothiazolinone, benzyl alcohol, sodium benzoate and methylparaben were separated on a Chromolith Fast Gradient reversed-phase 18e column using gradient elution with acetonitrile and a 0.1% aqueous solution of formic acid, with a run time of 3 min. The preparation of solid and liquid samples included ultrasonic extraction with methanol with recoveries ranging from 69 to 119%. The developed method was used to analyze samples of cosmetics (66 samples), cleaning agents (five samples) and pharmaceutical industry products (17 samples). PMID:23324734

  4. Interfacial process of nucleation and molecular nucleation templator

    NASA Astrophysics Data System (ADS)

    Liu, X. Y.

    2001-07-01

    Interfacial effects of nucleation inhibition and promotion were identified from the nucleation of paracetamol. Unlike the classic interfacial effects, which are caused by the change in nucleation barrier, the nonepitaxial interfacial effects are only associated with kink integration kinetics. Methylparaben inhibits nucleation by increasing the desolvation free energy barrier, which is revealed as the nonepitaxial interfacial effect of nucleation inhibition. Polysaccharide revealed its nonepitaxial interfacial effects of nucleation promotion by lowering the conformation entropic barrier via liquid molecule preordering. Polysaccharide can be regarded as an example of molecular nucleation promoter based on the nonepitaxial interfacial effects.

  5. The consequence of the chemical composition of HPMC in matrix tablets on the release behaviour of model drug substances having different solubility.

    PubMed

    Viridén, Anna; Wittgren, Bengt; Larsson, Anette

    2011-01-01

    This study investigates the effect of the chemical heterogeneity of hydroxypropyl methylcellulose (HPMC) on the release of model drug substances from hydrophilic matrix tablets. The hypothesis was that the release of drug substances could be influenced by possible interactions with HPMC batches having different chemical heterogeneity. The cloud point of the most heterogeneous batch was more affected by the model drug substances, methylparaben and butylparaben, and most by butylparaben with the lowest solubility. The different clouding behaviour was explained by the heterogeneously substituted batches being more associative and the more lipophilic butylparaben being able to interact more efficiently with the hydrophobic HPMC transient crosslinks that formed. Interestingly, tablet compositions of the heterogeneously substituted HPMC batches released the more soluble methylparaben at lower rates than butylparaben. The explanation is that the hydrophobic HPMC interactions with butylparaben made the gel of the tablet less hydrated and more fragile and therefore more affected by erosional stresses. In contrast, drug release from compositions consisting of the more homogeneously substituted batches was affected to a minor extent by the drugs and was very robust within the experimental variations. The present study thus reveals that there can be variability in drug release depending on the lipophilicity of the drug and the substituent heterogeneity of the HPMC used. PMID:21081160

  6. Personal care product preservatives: risk assessment and mixture toxicities with an industrial wastewater.

    PubMed

    Carbajo, Jose B; Perdigón-Melón, Jose A; Petre, Alice L; Rosal, Roberto; Letón, Pedro; García-Calvo, Eloy

    2015-04-01

    The aquatic toxicity of eight preservatives frequently used in personal care products (PCPs) (iodopropynyl butylcarbamate, bronopol, diazolidinyl urea, benzalkonium chloride, zinc pyrithione, propylparaben, triclosan and a mixture of methylchloroisothiazolinone and methylisothiazolinone) was assessed by means of two different approaches: a battery of bioassays composed of single species tests of bacteria (Vibrio fischeri and Pseudomonas putida) and protozoa (Tetrahymena thermophila), and a whole biological community resazurin-based assay using activated sludge. The tested preservatives showed considerable toxicity in the studied bioassays, but with a marked difference in potency. In fact, all biocides except propylparaben and diazolidinyl urea had EC50 values lower than 1 mg L(-1) in at least one assay. Risk quotients for zinc pyrithione, benzalkonium chloride, iodopropynyl butylcarbamate and triclosan as well as the mixture of the studied preservatives exceeded 1, indicating a potential risk for the process performance and efficiency of municipal sewage treatment plants (STPs). These four single biocides explained more than 95% of the preservative mixture risk in all bioassays. Each individual preservative was also tested in combination with an industrial wastewater (IWW) from a cosmetics manufacturing facility. The toxicity assessment was performed on binary mixtures (preservative + IWW) and carried out using the median-effect principle, which is a special case of the concept of Concentration Addition (CA). Almost 70% of all experiments resulted in EC50 values within a factor of 2 of the values predicted by the median-effect principle (CI values between 0.5 and 2). The rest of the mixtures whose toxicity was mispredicted by CA were assessed with the alternative concept of Independent Action (IA), which showed higher predictive power for the biological community assay. Therefore, the concept used to accurately predict the toxicity of mixtures of a preservative with a complex industrial wastewater depends on degree of biological complexity. PMID:25585550

  7. Estrogenicity of parabens revisited: impact of parabens on early pregnancy and an uterotrophic assay in mice.

    PubMed

    Shaw, Jordan; deCatanzaro, Denys

    2009-07-01

    Parabens, a class of preservatives routinely added to cosmetics, pharmaceuticals, and foods, have estrogenic properties. Given that intrauterine implantation of fertilized ova in inseminated females can be disrupted by minute levels of exogenous estrogens, we assessed the impact of parabens upon early gestation. In Experiment 1, butylparaben was administered subcutaneously in several doses ranging from 0.05 to 35 mg/animal/day to inseminated CF-1 mice on days 1-4 of pregnancy. Butylparaben exposure did not affect litter size, the number of pups born, postnatal day 3 litter weights, or the number of pups surviving to postnatal day 5. In contrast, administration of 500 ng/animal/day 17beta-estradiol terminated all pregnancies. In Experiment 2, propylparaben was subcutaneously administered to inseminated CF-1 mice on gestational days 1-4. Dams were sacrificed on gestation day 6 and the number of implantation sites was counted. Propylparaben had no impact on the number of implantation sites observed. Since Experiments 1 and 2 did not yield the anticipated results, an uterotrophic assay was conducted in Experiment 3 to re-evaluate the in vivo estrogenicity of parabens. Ovariectomized CF-1 and CD-1 mice were administered butylparaben in doses ranging from 0.735 to 35 mg per animal for three consecutive days. Mice were sacrificed on the fourth day, and uterine mass was recorded. There was no effect of butylparaben on uterine wet or dry mass at any dose in either strain. In contrast, administration of 17beta-estradiol consistently increased uterine mass in both strains. These data indicate that the estrogen-sensitive period of implantation is not vulnerable to paraben exposure, and that the in vivo estrogenicity of parabens may not be as potent as previously reported. PMID:19490991

  8. A novel application of Onyxtrade mark monolithic column for simultaneous determination of salicylic acid and triamcinolone acetonide by sequential injection chromatography.

    PubMed

    Chocholous, Petr; Holík, Pavel; Satínský, Dalibor; Solich, Petr

    2007-04-30

    A novel and fast simultaneous determination of triamcinolone acetonide (TCA) and salicylic acid (SA) in topical pharmaceutical formulations by sequential injection chromatography (SIC) as an alternative to classical high performance liquid chromatography (HPLC) has been developed. A recently introduced Onyxtrade mark monolithic C18 (50mmx4.6mm, Phenomenex((R))) with 5mm monolithic precolumn were used for the first time for creating sequential injection chromatography system based on a FIAlab((R)) 3000 with a six-port selection valve and 5.0mL syringe pump in study. The mobile phase used was acetonitrile/water (35:65, v/v), pH 3.3 adjusted with acetic acid at flow rate 0.9mLmin(-1). UV detection provided by fibre-optic DAD detector was set up at 240nm. Propylparaben was chosen as suitable internal standard (IS). There is only simple pre-adjustment of the sample of topical solution (dilution with mobile phase) so the analysis is not uselessly elongated. Parameters of the method showed good linearity in wide range, correlation coefficient >0.999; system precision (relative standard deviation, R.S.D.) in the range 0.45-1.95% at three different concentration levels, detection limits (3sigma) 1.00mugmL(-1) (salicylic acid), 0.66mugmL(-1) (triamcinolone acetonide) and 0.33mugmL(-1) (propylparaben) and recovery from the pharmaceutical preparations in the range 97.50-98.94%. The chromatographic resolution between peaks of compounds was more than 4.5 and analysis time was 5.1min under the optimal conditions. The advantages of sequential injection chromatography against classical HPLC are discussed and showing that SIC can be a method of option in many cases. PMID:19071698

  9. Resolution of isomers of sorbitolparaben esters by chromatographic and electrophoretic techniques.

    PubMed

    Blanco, M; Coello, J; Iturriaga, H; Maspoch, S; Romero, M A

    2001-03-01

    Pharmaceutical preparations usually contain preservatives and sweeteners. When parabens are used as preservatives and a polyol as a sweetener, a transesterification reaction may happen, yielding the transester polyol-paraben. The products formed in the transesterification reaction of methylparaben and sorbitol were analyzed by micellar electrokinetic chromatography and by HPLC. Up to six positional isomers of sorbitolparaben (SPB) can be produced. However, only three peaks were found by HPLC. The higher efficiency and resolution power of MEKC allowed one to resolve five peaks. Results were compared with those obtained by capillary zone electrophoresis in borate buffer, where the separation of isomers occurred in a different way, because of a complexation between SPB and borate. PMID:11254204

  10. Biocides in the Yangtze River of China: spatiotemporal distribution, mass load and risk assessment.

    PubMed

    Liu, Wang-Rong; Zhao, Jian-Liang; Liu, You-Sheng; Chen, Zhi-Feng; Yang, Yuan-Yuan; Zhang, Qian-Qian; Ying, Guang-Guo

    2015-05-01

    Nineteen biocides were investigated in the Yangtze River to understand their spatiotemporal distribution, mass loads and ecological risks. Fourteen biocides were detected, with the highest concentrations up to 166 ng/L for DEET in surface water, and 54.3 ng/g dry weight (dw) for triclocarban in sediment. The dominant biocides were DEET and methylparaben, with their detection frequencies of 100% in both phases. An estimate of 152 t/y of 14 biocides was carried by the Yangtze River to the East China Sea. The distribution of biocides in the aquatic environments was significantly correlated to Gross Domestic Product (GDP), total phosphorus (TP) and total nitrogen (TN), suggesting dominant input sources from domestic wastewater of the cities along the river. Risk assessment showed high ecological risks posed by carbendazim in both phases and by triclosan in sediment. Therefore, proper measures should be taken to reduce the input of biocides into the river systems. PMID:25697474

  11. Ultra-performance liquid chromatography MS/MS method for the determination of parabens in compost from sewage sludge: comparison of the efficiency of two extraction techniques.

    PubMed

    Benítez-Villalba, Julio César; Zafra-Gómez, Alberto; Dorival-García, Noemí; Camino-Sánchez, Francisco Javier; Cantarero, Samuel; Vílchez, José Luis

    2013-08-01

    The efficiency of two extraction techniques--ultrasound-assisted extraction and pressurized liquid extraction--are compared and evaluated in the determination of parabens in compost samples. The extraction parameters for each technique were accurately optimized. The selected compounds were detected and quantified using ultra-performance LC MS/MS, operating in negative ESI and in SRM mode. The analytes were separated in less than 5 min. Ethylparaben (ring-(13)C6 labeled) was used as an internal standard. Two selective, sensitive, and accurate analytical methods were developed and validated. The LODs of the methods ranged from 3 to 7 ng/g and the LOQs from 10 to 23 ng/g, while inter- and intraday variability was under 6% in all cases. The methods were validated separately by using matrix-matched calibration and recovery assays with spiked samples. Recovery rates ranged from 94.0 to 105.0%. Compost samples were taken from different composting plants. Although the statistical comparison demonstrated no statistically significant differences between the two extraction techniques, the method based on pressurized liquid extraction was more sensitive than the ultrasound extraction based method. PMID:23868707

  12. Analysis of daidzein in nanoparticles after oral co-administration with sodium caprate to rats by ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry.

    PubMed

    Ma, Yiran; Zhang, Li; Zhao, Xinyi; Shen, Qi

    2012-10-15

    An ultra-performance-liquid-chromatography-quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS) method was developed and validated for the quantitation of daidzein (DZ) in rat plasma. Ethylparaben was chosen as internal standards (IS). DZ was linear over the range of 0.001-5 ?g/mL. The lower limit of quantification (LLOQ) was 0.001 ?g/mL and the limit of detection (LOD) was 0.0005 ?g/mL. The intra-day and inter-day relative standard deviations (RSDs) were ranged from 3.59% to 6.43% and 5.35% to 7.25%, respectively. This UPLC/Q-TOF-MS method provided good specifity, highly sensitivity, accurate and high-speed detection (6 min), applicable to the pharmacokinetics study in rats in vivo after oral administration of free daidzein solution, daidzein-loaded poly (lactide-co-glycolide) (PLGA) nanoparticles (D-NPs) suspension and D-NPs co-administered with sodium caprate (C(10)) which as the oral absorption promoter. It was shown that the pharmacokinetics behavior was significantly improved after the oral administration of D-NPs suspension co-administered with absorption promoter C(10) by the fact that the relative bioavailability were enhanced about 4.24-fold, compared to that of DZ suspension. PMID:23010479

  13. UHPLC-MS/MS method for the determination of bisphenol A and its chlorinated derivatives, bisphenol S, parabens, and benzophenones in human urine samples.

    PubMed

    Vela-Soria, F; Ballesteros, O; Zafra-Gómez, A; Ballesteros, L; Navalón, A

    2014-06-01

    In the present work, a new method based on a sample treatment by dispersive liquid-liquid microextraction (DLLME) for the extraction of six bisphenols (bisphenol A, bisphenol S, and monochloro-, dichloro-, trichloro-, and tetrachlorobisphenol A), four parabens (methyl-, ethyl-, propyl-, and butylparaben), and six benzophenones (benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-6, benzophenone-8, and 4-hydroxybenzophenone) in human urine samples, followed by ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis, is validated. An enzymatic treatment allows determining the total content of the target EDCs. The extraction parameters were accurately optimized using multivariate optimization strategies. Ethylparaben ring-(13)C6, benzophenone-d10, and bisphenol A-d16 were used as surrogates. Limits of quantification ranging from 0.1 to 0.6 ng mL(-1) and interday variabilities (evaluated as relative standard deviations) from 2.0 to 13.8% were obtained. The method was validated using matrix-matched standard calibration followed by a recovery assay with spiked samples. Recovery rates ranged from 94 to 106%. A good linearity, for concentrations up to 300 ng mL(-1) for parabens and 40 ng mL(-1) for benzophenones and bisphenols, was also obtained. The method was satisfactorily applied for the determination of target compounds in human urine samples from 20 randomly selected individuals. PMID:24710638

  14. Using infective mosquitoes to challenge monkeys with Plasmodium knowlesi in malaria vaccine studies

    PubMed Central

    2014-01-01

    Background When rhesus monkeys (Macaca mulatta) are used to test malaria vaccines, animals are often challenged by the intravenous injection of sporozoites. However, natural exposure to malaria comes via mosquito bite, and antibodies can neutralize sporozoites as they traverse the skin. Thus, intravenous injection may not fairly assess humoral immunity from anti-sporozoite malaria vaccines. To better assess malaria vaccines in rhesus, a method to challenge large numbers of monkeys by mosquito bite was developed. Methods Several species and strains of mosquitoes were tested for their ability to produce Plasmodium knowlesi sporozoites. Donor monkey parasitaemia effects on oocyst and sporozoite numbers and mosquito mortality were documented. Methylparaben added to mosquito feed was tested to improve mosquito survival. To determine the number of bites needed to infect a monkey, animals were exposed to various numbers of P. knowlesi-infected mosquitoes. Finally, P. knowlesi-infected mosquitoes were used to challenge 17 monkeys in a malaria vaccine trial, and the effect of number of infectious bites on monkey parasitaemia was documented. Results Anopheles dirus, Anopheles crascens, and Anopheles dirus X (a cross between the two species) produced large numbers of P. knowlesi sporozoites. Mosquito survival to day 14, when sporozoites fill the salivary glands, averaged only 32% when donor monkeys had a parasitaemia above 2%. However, when donor monkey parasitaemia was below 2%, mosquitoes survived twice as well and contained ample sporozoites in their salivary glands. Adding methylparaben to sugar solutions did not improve survival of infected mosquitoes. Plasmodium knowlesi was very infectious, with all monkeys developing blood stage infections if one or more infected mosquitoes successfully fed. There was also a dose-response, with monkeys that received higher numbers of infected mosquito bites developing malaria sooner. Conclusions Anopheles dirus, An. crascens and a cross between these two species all were excellent vectors for P. knowlesi. High donor monkey parasitaemia was associated with poor mosquito survival. A single infected mosquito bite is likely sufficient to infect a monkey with P. knowlesi. It is possible to efficiently challenge large groups of monkeys by mosquito bite, which will be useful for P. knowlesi vaccine studies. PMID:24893777

  15. Quantitation of buclizine hydrochloride in pharmaceutical formulations and human serum by RP-HPLC.

    PubMed

    Arayne, M Saeed; Sultana, Najma; Siddiqui, Farhan Ahmed

    2006-10-01

    An isocratic reversed phase high-performance liquid chromatographic (HPLC) method with ultraviolet detection at 230 nm has been developed for the determination of buclizine hydrochloride in human serum and dosage formulation. Methylparaben was successfully used as an internal standard. Good chromatographic separation between buclizine and internal standard peaks was achieved by using a stainless steel analytical column Nucleosil, C18 (10 microm, 25 cm x 0.46 cm). The system was operated at room temperature using a mobile phase consisting of acetonitrile-water (1:1) (pH 2.6) with phosphoric acid 85% at a flow rate of 2 ml/min. The calibration curve for buclizine hydrochloride in human serum was linear over the tested concentration range of 10, 3, 1.5, 0.5, 0.15, 0.05, and 0.025 microg/ml with a correlation coefficient of 0.9999. The intra- and inter-run precision and accuracy results were 98.07 to 100.34. The proposed method was validated for selectivity, linearity, accuracy, and precision. The method was found to be suitable for the quality control of buclizine hydrochloride in bulk drug as well as in human serum. PMID:17105713

  16. Effect of maternal exposure to endocrine disrupting chemicals on reproduction and mammary gland development in female Sprague-Dawley rats.

    PubMed

    Manservisi, Fabiana; Gopalakrishnan, Kalpana; Tibaldi, Eva; Hysi, Albana; Iezzi, Manuela; Lambertini, Luca; Teitelbaum, Susan; Chen, Jia; Belpoggi, Fiorella

    2015-07-01

    The aim of the study is to determine whether low doses of "endocrine disrupting chemicals" (EDCs) affect the development and proliferative activity of the mammary glands (MGs). Adult parous/nulliparous female Sprague-Dawley (SD) rats were treated from post-natal day (PND) 1 until PND 180 with diethylphthalate (DEP), methylparaben (MPB), triclosan (TCS) and a mixture at doses comparable to human exposure. The doses (mg/kg b.w./day) were: DEP=0.173; MPB=0.105; TCS=0.05. EDC treatment resulted in mortality rates >20% in pups as early as lactation day 7. Significant morphological/histological changes were observed at the end of lactation in the MGs of EDC-treated dams. The total transcriptome profile as well as lactation-related genes in MGs also corroborate the morphological findings as more profound gene expression changes are present only at the weaning period. The study highlights the heightened sensitivity of the MGs during critical windows of exposure, particularly pregnancy and lactation, with an impact on pups' survival. PMID:25554385

  17. Gene expression responses for detecting sublethal effects of xenobiotics and whole effluents on a Xenopus laevis embryo assay.

    PubMed

    San Segundo, Laura; Martini, Federica; Pablos, M Victoria

    2013-09-01

    In the present study, the authors investigated the effects of bisphenol A, chlorpyrifos, methylparaben, and 2 effluent samples from wastewater treatment plants located in the province of Madrid, Spain, on the messenger RNA expression of specific genes involved in early development (ESR1, pax6, bmp4, and myf5) and a gene involved in the general stress response (hsp70) during Xenopus laevis embryo development. Gene expression was analyzed after 4?h, 24?h, and 96?h of exposure by semiquantitative reverse-transcriptase-polymerase chain reaction. Concentration ranges of the compounds and dilutions for the samples were selected to cause morphological alterations in embryos after 96?h of exposure. Transcript levels of ESR1, pax6, and hsp70 were differentially altered at early developmental stages with patterns specific to the contaminant and the exposure time. However, further studies are needed to establish transcript levels of specific genes as biomarkers of sublethal effects in an environmental risk-assessment framework. Besides, studies including more generic responses, such as genes encoding antioxidant enzymes, together with genes related to embryonic development have to be developed to look for a battery of mechanistic endpoints for the evaluation of chemical exposure at the molecular level in a first-tier assessment. PMID:23637088

  18. Quaternary polymethacrylate-magnesium aluminum silicate films: Water uptake kinetics and film permeability.

    PubMed

    Rongthong, Thitiphorn; Sungthongjeen, Srisagul; Siepmann, Florence; Siepmann, Juergen; Pongjanyakul, Thaned

    2015-07-25

    The aim of this study was to investigate the impact of the addition of different amounts of magnesium aluminum silicate (MAS) to polymeric films based on quaternary polymethacrylates (QPMs, here Eudragit RS and RL). MAS contains negatively charged SiO(-) groups, while QPM contains positively charged quaternary ammonium groups. The basic idea is to be able to provide desired water and drug permeability by simply varying the amount of added MAS. Thin, free films of varying composition were prepared by casting and exposed to 0.1M HCl and pH 6.8 phosphate buffer. The water uptake kinetics and water vapor permeability of the systems were determined gravimetrically. The transport of propranolol HCl, acetaminophen, methyl-, ethyl- and propylparaben across thin films was studied using side-by-side diffusion cells. A numerical solution of Fick's second law of diffusion was applied to determine the apparent compound diffusion coefficients, partition coefficients between the bulk fluids and the films as well as the apparent film permeability for these compounds. The addition of MAS resulted in denser inner film structures, at least partially due to ionic interactions between the positively charged quaternary ammonium groups and the negatively charged SiO(-) groups. This resulted in lower water uptake, reduced water vapor permeability and decreasing apparent compound diffusivities. In contrast, the affinity of the investigated drugs and parabens to the films substantially increased upon MAS addition. The obtained new knowledge can be helpful for the development of novel coating materials (based on QPM-MAS blends) for controlled-release dosage forms. PMID:26004005

  19. Determination of micropollutants in combined sewer overflows and their removal in a wastewater treatment plant (Seoul, South Korea).

    PubMed

    Ryu, Jaena; Oh, Jeill; Snyder, Shane A; Yoon, Yeomin

    2014-05-01

    The present study investigated the occurrence of 29 selected micropollutants such as endocrine disrupting compounds (EDCs) and pharmaceuticals and personal care products (PPCPs) in surface waters and wastewaters in Seoul (South Korea) during both dry and wet weather conditions. The study area was selected based on the lack of available information regarding the suspected contamination of rivers/creeks by EDCs and PPCPs in the Seoul region and the presence of a wastewater treatment plant (WWTP), which serves approximately 4.1 million inhabitants and has a design capacity of 1,297 × 10(3) m(3)/day. Many target compounds (83 %) were detected in samples collected from wastewater treatment influent/effluent, creek water, and combined sewer overflow (CSO). The total EDC/PPCP concentrations were as follows: WWTP influent (69,903 ng/L)?>?WWTP effluent (50,175 ng/L) >3 creek samples (16,035-44,446 ng/L) during dry weather, and WWTP influent (53,795 ng/L)?>?WWTP bypass (38,653 ng/L) >5 creek samples (15,260-29,113 ng/L) >2 CSO samples (11,109-11,498 ng/L) during wet weather. EDCs and PPCPs were found to be present at high daily loads (65.1 and 69.8 kg/day during dry and wet weather, respectively) in the WWTP effluent. Compound removal by the WWTP varied significantly by compound: caffeine, diclofenac, ibuprofen, naproxen, and propylparaben (>90 %), and acesulfame, DEET, iohexol, iopromide, and iopamidol (<5 %). These findings and literature information support the hypothesis that the efficiency of removal of EDCs and PPCPs is strongly dependent on both removal mechanism (e.g., biodegradation, adsorption to sludge, and oxidation by chlorine) and compound physicochemical properties (e.g., pK a and hydrophobicity). PMID:24415065

  20. Simultaneous determination of some water-soluble vitamins and preservatives in multivitamin syrup by validated stability-indicating high-performance liquid chromatography method.

    PubMed

    Vidovi?, Stojanka; Stojanovi?, Biljana; Veljkovi?, Jelena; Prazi?-Arsi?, Ljiljana; Rogli?, Goran; Manojlovi?, Dragan

    2008-08-22

    HPLC stability-indicating method has been developed for the simultaneous determination of some water-soluble vitamins (ascorbic acid, thiamine hydrochloride, riboflavin-5'-phosphate sodium, pyridoxine hydrochloride, nicotinamide, D(+)-panthenol) and two preservatives (methylparaben and sodium benzoate) in multivitamin syrup preparation. Water-soluble vitamins, preservatives and their degradants were separated on Zorbax SB-Aq (C(18)) (250 mm x 4.6 mm, 5 microm) column at an ambient temperature. Combined isocratic and gradient elution was performed with a mobile phase consisting of 0.0125 M hexane-1-sulfonic acid sodium salt in 0.1% (m/v) o-phosphoric acid, pH 2.4-2.5 (solvent A) and acetonitrile (solvent B) at the flow-rate 1 ml min(-1). Starting with solvent A an isocratic elution was performed for 15 min, then the composition was changed to 85% of A and 15% of B during the next 20 min and it was constant for 5 min, then the composition was changed to 70% of A and 30% of B during next 15 min and it was constant for 5 min and finally was changed to 100% of A as at the beginning of the elution. Detection was performed with diode array detector at 210, 230 and 254 nm. Multivitamin syrup preparation was subjected to stress testing (forced degradation) in order to demonstrate that degradants from the vitamins, preservatives and/or product excipients do not interfere with the quantification of vitamins and preservatives. Typical validation characteristics: selectivity, accuracy, precision, linearity, range, limit of quantification and limit of detection were evaluated for vitamins and preservatives. PMID:18644604

  1. Characterization of the organic contamination pattern of a hyper-saline ecosystem by rapid screening using gas chromatography coupled to high-resolution time-of-flight mass spectrometry.

    PubMed

    Serrano, Roque; Portolés, Tania; Blanes, Miguel A; Hernández, Félix; Navarro, Juan C; Varó, Inmaculada; Amat, Francisco

    2012-09-01

    In this paper, gas chromatography coupled to high-resolution time-of-flight mass spectrometry (GC-TOF MS) has been applied to evaluate organic pollution in a hyper-saline aquatic environment. Firstly, a target screening was made for a list of 150 GC-amenable organic micro-contaminants, including PAHs, octyl/nonyl phenols, PCBs, PBDEs, and a notable number of pesticides, such us insecticides (organochlorines, organophosphorus, carbamates and pyrethroids), herbicides (triazines and chloroacetanilides), fungicides and several transformation products. This methodology was applied to brine samples, with a salt content from 112 g/L to saturation, and to samples from Artemia populations (crustacean Anostraca) collected during 1 year from three sampling stations in saltworks bodies sited in the Ebro river delta. Around 50 target contaminants, belong to chemical families included in the list of priority substances within the framework on European water policy. Additionally, a non-target analysis was performed in both types of samples with the objective of investigating the presence of other non-selected organic compounds taking advantage of the potential of GC-TOF MS (high sensitivity in full-spectrum acquisition mode, accurate mass measurements) for searching unknowns. Organophosphorus pesticides were the contaminants more frequently detected in brine samples. Other compounds usually present in urban and industrial wastewaters, like caffeine, methylparaben, butylated-hydroxytoluene and N-butylbenzenesulfonamide were also detected in brines. The herbicide simazine and the insecticide chlorpyrifos were among the contaminants detected in Artemia samples. Results of this work reveal a potential threat to vulnerable populations inhabiting the hyper-saline ecosystem. The valuable contribution of GC-TOF MS in environmental analysis, allowing the rapid screening of a large number of organic contaminants, is also demonstrated in this paper. PMID:22789816

  2. A novel complex of a phenolic derivative with insulin: structural features related to the T-->R transition.

    PubMed Central

    Smith, G. D.; Ciszak, E.; Pangborn, W.

    1996-01-01

    The structure of a symmetric T3R3f insulin hexamer, complexed with 4-hydroxybenzamide, has been determined using X-ray crystallographic techniques. Data were measured from six crystals grown in microgravity to a resolution of 1.4 A and the structure has been refined including the contributions from hydrogen atoms. The crystals are isomorphous with T3R3f complexes of phenolic derivatives as well as with uncomplexed forms. Unlike the structures of complexes with phenol, m-cresol, resorcinol, 4'-hydroxyacetanilide, and methylparaben, which bind one phenolic derivative molecule per R- or Rf-state monomer, two molecules of 4-hydroxybenzamide are bound by each Rf-state monomer. The presence of the second guest molecule results in an extensive hydrogen bonding network, mediated by water molecules, between the T- and Rf-state trimers and adds stability to the formation of the hexamer. The only access to these second sites is through three symmetry-related, narrow channels that originate on the surface of the T-state trimer. Although the conformation of the backbone atoms of the monomers is nearly identical to that of other T3R3f hexamers, significant changes are observed in the conformations of side chains in the vicinity of the second binding site. The side chain of the T-state A11 Cys residue, which forms a disulfide bond to A6 Cys in the same monomer, is observed in two discrete conformations; two discrete conformations are also present for the entire A8 Thr residue in the Rf-state monomer. A procedure is also described for an alternate method of interframe scaling and merging intensity data from an image plate detector. PMID:8844841

  3. Prenatal Exposure to Environmental Phenols: Concentrations in Amniotic Fluid and Variability in Urinary Concentrations during Pregnancy

    PubMed Central

    Wolff, Mary S.; Calafat, Antonia M.; Ye, Xiaoyun; Bausell, Rebecca; Meadows, Molly; Stone, Joanne; Slama, Rémy; Engel, Stephanie M.

    2013-01-01

    Background: Maternal urinary biomarkers are often used to assess fetal exposure to phenols and their precursors. Their effectiveness as a measure of exposure in epidemiological studies depends on their variability during pregnancy and their ability to accurately predict fetal exposure. Objectives: We assessed the relationship between urinary and amniotic fluid concentrations of nine environmental phenols, and the reproducibility of urinary concentrations, among pregnant women. Methods: Seventy-one women referred for amniocentesis were included. Maternal urine was collected at the time of the amniocentesis appointment and on two subsequent occasions. Urine and amniotic fluid were analyzed for 2,4- and 2,5-dichlorophenols, bisphenol A, benzophenone-3, triclosan, and methyl-, ethyl-, propyl-, and butylparabens using online solid phase extraction–high performance liquid chromatography–isotope dilution tandem mass spectrometry. Results: Only benzophenone-3 and propylparaben were detectable in more than half of the amniotic fluid samples; for these phenols, concentrations in amniotic fluid and maternal urine collected on the same day were positively correlated (? = 0.53 and 0.32, respectively). Other phenols were detected infrequently in amniotic fluid (e.g., bisphenol A was detected in only two samples). The intraclass correlation coefficients (ICCs) of urinary concentrations in samples from individual women ranged from 0.48 and 0.62 for all phenols except bisphenol A (ICC = 0.11). Conclusion: Amniotic fluid detection frequencies for most phenols were low. The reproducibility of urine measures was poor for bisphenol A, but good for the other phenols. Although a single sample may provide a reasonable estimate of exposure for some phenols, collecting multiple urine samples during pregnancy is an option to reduce exposure measurement error in studies regarding the effects of phenol prenatal exposure on health. Citation: Philippat C, Wolff MS, Calafat AM, Ye X, Bausell R, Meadows M, Stone J, Slama R, Engel SM. 2013. Prenatal exposure to environmental phenols: concentrations in amniotic fluid and variability in urinary concentrations during pregnancy. Environ Health Perspect 121:1225–1231;?http://dx.doi.org/10.1289/ehp.1206335 PMID:23942273