نتایج جستجو برای: propyl paraben
تعداد نتایج: 4641 فیلتر نتایج به سال:
BACKGROUND Exposures to environmental phenols and parabens may be harmful, especially in utero. Prior studies have demonstrated high within-person variability of urinary concentrations across pregnancy. OBJECTIVES We sought to measure phenol and paraben biomarker concentrations for the Norwegian Mother and Child Cohort (MoBa) study, assess within-person variability, and investigate any possib...
Parabens are esters of p-hydroxybenzoic acid and belong to group of effective preservatives commonly used in cosmetic products, drugs and food. Their antimicrobial activity increases with increasing carbon number of the ester group. A number of cosmetic products and skincare products are preserved with parabens, as well in Europe as in the United States. Methyl, ethyl and propyl paraben are pre...
Objective: The aim of presented study was to develop a high-performance liquid chromatography (HPLC) method with UV detection for simultaneous determination of ketoprofen, methyl paraben and propyl paraben in a gel formulation. Methods: The chromatography was carried out on a C18 Results: Under these chromatographic conditions, the obtained retention times were approximately 2.41 min for methyl...
Screening of estrogenic activity on dichloro diphenyl trichloroethane (DDT), dichloro diphenyl dichloro ethylene (DDE), dieldrin, heptachlor, aldrin, chlordane, lindane, polybrominated diphenyl ethers (PBDE) and parabens was compared using Organization for Economic Cooperation and Development (OECD) test guideline 455 (TG455). The estrogenic activity of DDT was 58,000-fold (PC50, 1.67 × 10(-6) ...
The vaporization, fusion, and sublimation enthalpies of methyl, ethyl, propyl, and butyl paraben are reported and compared with literature values. The vaporization enthalpies were measured by correlation gas chromatography and the fusion enthalpies by differential scanning calorimetry. Adjusted to T = 298.15 K, these enthalpies were combined to yield the sublimation enthalpy. The results compar...
The effect of parabens on the shelf-life of crocetin esters and picrocrocin in aqueous saffron solutions was studied. Degradation of saffron crocetin esters fits a first-order kinetics model, and the results indicated that the crocetin (beta-D-glucosyl)-(beta-D-gentiobiosyl) esters were more stable than the crocetin di-(beta-D-gentiobiosyl) esters regardless of whether trans and cis isomers wer...
OBJECTIVES Possible relationship between semen quality (semen volume, sperm concentration and sperm motility) and parabens exposure was investigated in male partners of couples who visited a gynecology clinic in Tokyo for infertility consultation (n = 42, 36.8 ± 5.4 years). METHODS Semen parameters were measured according to WHO guideline at the clinic, and urinary methyl- (MP), ethyl- (EP), ...
Parabens, alkyl esters of p-hydroxybenzoic acid, including methyl paraben (MP), ethyl paraben (EP), propyl paraben (PP) and butyl paraben (BP), have been widely used as antimicrobial agents. Recently, parabens in cosmetic products have received keen attention, because the elevated amounts of parabens in topical products have been shown to induce allergic contact dermatitis to cancer. The potent...
The removal of four parabens, methyl-, ethyl-, propyl-, and benzyl-paraben, by β-cyclodextrin (β-CD) polymer from aqueous solution was studied. Different β-CD polymers were prepared by using two cross-linkers, i.e., hexamethylene diisocyanate (HMDI) and toluene-2,6-diisocyanate (TDI), with various molar ratios of cross-linker. β-CD-HMDI polymer with molar ratio of 1:7 and β-CD-TDI polymer with ...
the purpose of this research was to study the neutralization efficacy of a universal neutralizer proposed by the ctpa on a range of antimicrobial agents and its potential toxicity for microorganisms that are used for antimicrobial preservation testing. several types of antimicrobial agents including a mixture of methylisothiazolinone and its 5-chloro derivative, dimethylol dimethyl hydantoin, q...
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