Rapid, sensitive and simultaneous determination of 16 endocrine-disrupting chemicals (parabens, benzophenones, bisphenols, and triclocarban) in human urine based on microextraction by packed sorbent combined with liquid chromatography tandem mass spectrometry (MEPS-LC-MS/MS).

A high demand exists in human biomonitoring studies for reliable and straightforward methods that generate data faster and simultaneously. Thus, the present study combines microextraction by packed sorbent (MEPS) and liquid chromatography coupled to mass spectrometry (LC-MS/MS) for simultaneous extraction and determination of various classes of endocrine-disrupting chemicals (EDCs), including parabens, benzophenones, bisphenols, and the antimicrobial, triclocarban in human urine samples. Optimized MEPS conditions were: i) MEPS sorbent (C18), ii) pH of sample (3), iii) volume of sample (250 µL), iv) number of draws-eject cycles (5) and (vi) desorption solvent conditions (100 µL of CH3OH:H2O 80:20 v/v). The calibration curves were linear over the selected ranges for all studied compound, with correlation coefficients higher than 0.99. The variation coefficient for precision was lower than 20% at lower concentrations and lower than 15% at the higher concentrations studied. The accuracy ranged from 90% to 118%. The proposed strategy affords several advantages over currently published approaches, including simplicity of operation and reduction of sample and solvent volumes and time for matrix clean-up. Moreover, the analytical performance of each MEPS cartridge remained stable over the analysis of at least 70 samples (RSD < 10%). Thus, the current procedure may be an interesting high-throughput alternative for large routine human biomonitoring studies. Urinary geometric mean concentrations of EDCs obtained in this study were close than those previously reported for Brazilian children.

A fast and simple air-assisted liquid-liquid microextraction procedure for the simultaneous determination of bisphenols, parabens, benzophenones, triclosan, and triclocarban in human urine by liquid chromatography-tandem mass spectrometry.

The increasing awareness and public concern with hazard exposure to endocrine-disrupting chemicals calls for methods capable to handle numerous samples in short analysis time. In this present study, a novel method combining air-assisted liquid-liquid microextraction and liquid chromatography coupled to mass spectrometry was developed and validated for the extraction, preconcentration, and determination of 7 bisphenols (bisphenol A, bisphenol S, bisphenol AP, bisphenol P, bisphenol F, bisphenol AF, bisphenol Z), 7 parabens (methyl-, ethyl-, propyl-, butyl-, benzyl-paraben, methyl-protocatechuic acid, and ethyl-protocatechuic acid), 5 benzophenones (benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-8, and 4-hydroxybenzophenone), and two antimicrobials (triclosan and triclocarban) in human urine samples. Type and volume of solvent, extraction time (cycles), pH sample, ionic strength, agitation, and needle dimensions were evaluated. The matrix-matched calibration curves of all analytes were linear with correlation coefficients higher than 0.99 in the range level of 1.0-20.0 ng mL-1. The relative standard deviation, precision, at three concentrations (1.0, 10.0 and 20.0 ng mL-1) was lower than 15% with accuracy ranging from 90% to 114%. The biomonitoring capability of the new proposed method was confirmed with the analysis of 50 human urine samples randomly collected from Brazilian children. High urinary concentrations of several EDCs associated with usage of personal care products were found.

Associations between urinary phenol and paraben concentrations and markers of oxidative stress and inflammation among pregnant women in Puerto Rico.

Phenols and parabens are used in a multitude of consumer products resulting in ubiquitous human exposure. Animal and in vitro studies suggest that exposure to these compounds may be related to a number of adverse health outcomes, as well as potential mediators such as oxidative stress and inflammation. We examined urinary phenol (bisphenol A (BPA), triclosan (TCS), benzophenone-3 (BP-3), 2,4-dichlorophenol (24-DCP), 2,5-dichlorophenol (25-DCP)) and paraben (butyl paraben (B-PB), methyl paraben (M-PB), propyl paraben (P-PB)) concentrations measured three times during pregnancy in relation to markers of oxidative stress and inflammation among participants in the Puerto Rico Testsite for Exploring Contamination Threats (PROTECT) project. Serum markers of inflammation (c-reactive protein (CRP), IL-1ß, IL-6, IL-10, and tumor necrosis factor-α (TNF-α)) were measured twice during pregnancy (n=105 subjects, 187 measurements) and urinary markers of oxidative stress (8-hydroxydeoxyguanosine (OHdG) and isoprostane) were measured three times during pregnancy (n=54 subjects, 146 measurements). We used linear mixed models to assess relationships between natural log-transformed exposure and outcome biomarkers while accounting for within individual correlation across study visits. After adjustment for urinary specific gravity, study visit, maternal pre-pregnancy BMI, and maternal education, an interquartile range (IQR) increase in urinary BPA was associated with 21% higher OHdG (p=0.001) and 29% higher isoprostane (p=0.0002), indicating increased oxidative stress. The adjusted increase in isoprostane per IQR increase in marker of exposure was 17% for BP-3, 27% for B-PB, and 20% for P-PB (all p<0.05). An IQR increase in triclosan (TCS) was associated with 31% higher serum concentrations of IL-6 (p=0.007), a pro-inflammatory cytokine. In contrast, IQR increases in BP-3 and B-PB were significantly associated with 16% and 18% lower CRP, a measure of systemic inflammation. Our findings suggest that exposure to BPA, select parabens, and TCS during pregnancy may be related to oxidative stress and inflammation, potential mechanisms by which exposure to these compounds may influence birth outcomes and other adverse health effects, but additional research is needed.

Deteminación de 1,4-benzodiazepinas en orina por cromatografía líquida de alta eficacia / Determination of 1,4-benzodiazepines in urine by high performance liquid chromatography

Se describe un método de determinación de 1,4-benzodiazepinas en orina por cromatografía líquida de alta eficacia, luego de la hidrólisis ácida a sus correspondientes benzofenonas. En el presente trabajo se logró optimizar el rendimiento en benzofenonas variando las condiciones de hidrólisis y empleando diferentes pH y solventes de extracción. La separación de las benzofenonas se llevó a cabo con una columna de fase reversa de octadecilsilano, en condiciones isocráticas y detección UV a 254 nm. La sensibilidad del método es de 250 ng de benzodiazepina por ml de orina

Deteminación de 1,4-benzodiazepinas en orina por cromatografía líquida de alta eficacia / Determination of 1,4-benzodiazepines in urine by high performance liquid chromatography

Se describe un método de determinación de 1,4-benzodiazepinas en orina por cromatografía líquida de alta eficacia, luego de la hidrólisis ácida a sus correspondientes benzofenonas. En el presente trabajo se logró optimizar el rendimiento en benzofenonas variando las condiciones de hidrólisis y empleando diferentes pH y solventes de extracción. La separación de las benzofenonas se llevó a cabo con una columna de fase reversa de octadecilsilano, en condiciones isocráticas y detección UV a 254 nm. La sensibilidad del método es de 250 ng de benzodiazepina por ml de orina (AU)