Analysis of an Alanine/Arginine Mixture by Using TLC/FTIR Technique

We applied TLC/FTIR coupled with mapping technique to analyze an alanine/arginine mixture. Narrow band TLC plates prepared by using AgI as a stationary phase were used to separate alanine and arginine. The distribution of alanine and arginine spots was manifested by a 3D chromatogram. Alanine and arginine can be successfully separated by the narrow band TLC plate. In addition, the FTIR spectra of the separated alanine and arginine spots on the narrow band TLC plate are roughly the same as the corresponding reference IR spectra

Personal exposure to fine particles (PM2.5) and respiratory inflammation o common residents in Hong Kong

Background: Given the lack of research on the personal exposure to fine particles (PM2.5) in Hong Kong, we examined the association between short-term personal exposure to PM2.5 and their constituents and inflammation in exhaled breath in a sample of healthy adult residents

Detection and Occurrence of Chlorinated Byproducts of Bisphenol A, Nonylphenol, and Estrogens in Drinking Water of China: Comparison to the Parent Compounds

This study applied a sensitive dansylation LC-MS/MS method to the investigation on the occurrence of bisphenol A (BPA), nonylphenol (NP), estrogens (E1 and E2), and their 11 chlorinated byproducts in 62 drinking water treatment plants (DWTPs) of 31 major cities across China. BPA (4.7–512 ng/L), NP (8.2–918 ng/L), and E1 (ND-9.9 ng/L) were widely detected in source waters, E2 was detected in less than half of the samples (ND-3.2 ng/L), while chlorinated byproducts were only detected in source waters of two DWTPs. In drinking water, chlorinated BPAs and monochloro-NP (MCNP) were detected in more than half of the samples with concentrations of 0.2–26.7 ng/L for monochloro-BPA (MCBPA), ND-6.3 ng/L for dichloro-BPA (DCBPA), ND-7.7 ng/L for trichloro-BPA (TCBPA), ND-4.8 ng/L for tetrachloro-BPA (TBBPA), and ND-13.3 ng/L for MCNP, while dichloro-E1 (DCE1, ND-0.2 ng/L) and dichloro-NP (DCNP, ND-1.6 ng/L) were less frequently detected (10/62 and 4/62). The production of chlorinated NPs in DWTPs was mainly influenced by the amount of NP in source water and chlorine added, while the concentrations of chlorinated BPAs in drinking waters were only found to be significantly correlated with those of BPA in source waters. Advanced treatment processes could be effective techniques for reducing target chlorinated byproducts in drinking water. This is the first report on the occurrence of chlorinated byproducts of BPA, NP, and estrogens in drinking water, and these chemicals should be considered when assessing the human risk of their parent compounds

Modulation of Benzo[a]pyrene-Induced Toxic Effects in Japanese Medaka (<i>Oryzias latipes</i>) by 2,2′,4,4′-Tetrabromodiphenyl Ether

Because polycyclic aromatic hydrocarbons (PAHs) and polybrominated diphenylethers (PBDEs) are ubiquitous and coexist in the environment and in wildlife, there are potential interactions between them that could cause toxic effects. In this study, the modulating effects of 2,2′,4,4′-tetrabromodiphenyl ether (BDE47) and benzo­[a]­pyrene (BaP)-induced reproductive and developmental toxic effects in Japanese medaka (Oryzias latipes) were investigated by exposing adult Japanese medaka to BaP alone, BDE47 alone, and coexposing them with both BaP and BDE47 at different concentrations, respectively. Exposure to BaP alone significantly suppressed fecundity and egg protein content and markedly induced skeletal deformation in F1 generation eleutheroembryos. BDE47 significantly recovered reproductive functions, fecundity, and egg protein content, suppressed by BaP when the concentration of BDE47 increased to 0.44 μg/L. Such effects can be at least partly explained by the decreased BaP levels in the coexposure groups and the accompanying increase in the circulating level of 17β-estradiol in female medaka fish. The prevalence of skeletal deformations markedly increased to 19.3 ± 2.4% and 16.0 ± 1.6% in fish coexposed to BaP and BDE47 at 0.44 and 2.58 μg/L compared with that of fish exposed to 1.21 μg/L BaP alone (9.7 ± 1.7%), and the impacts on male medaka fish in the coexposure groups would be the crucial reason leading to these effects. Considering that the measured water concentrations of BaP and BDE47 in the present study were comparable with those reported in rivers and harbors, BaP and BDE47 contamination in the real world would have a significant level of interactive effects on wild fish

Levels of Phthalate Metabolites in Urine of Pregnant Women and Risk of Clinical Pregnancy Loss

Toxicological studies have shown that phthalate esters (PAEs), a class of widely used and environmentally prevalent chemicals, can increase the abortion rate in animals, but epidemiological evidence is scarce. This study aimed to explore the relationship between the urinary concentration of phthalate metabolites and the risk of clinical pregnancy loss. A total of 132 women who underwent clinical pregnancy loss (cases) and 172 healthy pregnant women (controls) were recruited from Beijing, China. Eight phthalate metabolites in urine were determined by ultraperformance liquid chromatography tandem mass spectrometry (UPLC–MS/MS). Five phthalate metabolites, monomethyl phthalate (MMP), monoethyl phthalate (MEP), monoisobutyl phthalate (MiBP), mono-<i>n</i>-butyl phthalate (MnBP), and mono­(2-ethlyhexyl) phthalate (MEHP), were detected in at least 95% of the urine samples, with the highest median concentration of 51.0 μg/g of creatinine for MnBP of all participants. The differences in urinary concentrations of phthalate metabolites between cases and controls were evaluated using the Mann–Whitney <i>U</i> test. The concentrations of MEP (median of 18.7 μg/g of creatinine), MiBP (23.3 μg/g of creatinine), and MnBP (58.2 μg/g of creatinine) detected in the cases were significantly higher than those (15.7 μg/g of creatinine for MEP, 19.4 μg/g of creatinine for MiBP, and 43.9 μg/g of creatinine for MnBP) in the controls (<i>p</i> < 0.05). Increasing risks of clinical pregnancy loss were observed from the first to fourth quartiles of the MEP, MiBP, and MnBP concentrations (<i>p</i> < 0.05 for trend). We concluded that exposure to MEP, MiBP, and MnBP was associated with an increased risk of clinical pregnancy loss

Analysis of an Alanine/Arginine Mixture by Using TLC/FTIR Technique

We applied TLC/FTIR coupled with mapping technique to analyze an alanine/arginine mixture. Narrow band TLC plates prepared by using AgI as a stationary phase were used to separate alanine and arginine. The distribution of alanine and arginine spots was manifested by a 3D chromatogram. Alanine and arginine can be successfully separated by the narrow band TLC plate. In addition, the FTIR spectra of the separated alanine and arginine spots on the narrow band TLC plate are roughly the same as the corresponding reference IR spectra

Occurrence and Maternal Transfer of Chlorinated Bisphenol A and Nonylphenol in Pregnant Women and Their Matching Embryos

Prenatal exposure has recently raised concerns over the health risks of endocrine disruptors; however, little is known about their extent and the mechanisms of maternal transfer in the embryo stage. In this study, bisphenol A (BPA), nonylphenol (NP), and their six chlorinated derivatives were quantified in decidua samples from 25 pregnant women and their matching embryos, which were collected as chorionic villi samples. Monochloro-BPA (MCBPA), dichloro-BPA (DCBPA), monochloro-NP (MCNP), and dichloro-NP (DCNP) were detected in over 70% of the decidua or chorionic villi samples, while BPA, NP, trichloro-BPA (TCBPA), and tetrachloro-BPA (TeCBPA) were detected in less than half. The geometric mean (GM) concentrations of MCBPA, DCBPA, NP, MCNP, and DCNP in chorionic villi samples were 0.13, 0.17, 5.33, 4.52, and 2.44 ng/g dw, respectively, higher than those in maternal decidua samples, which were 0.10, 0.12, 3.27, 1.85, and 0.74 ng/g dw, respectively, while the GM concentration of BPA was lower in chorionic villi samples (0.09 ng/g dw) than in maternal decidua (0.10 ng/g dw). The ratios of the average lipid-normalized concentrations of chemicals in chorionic villi to those in maternal decidua (EMR) were calculated to be 1.53 for MCNP and 2.38 for DCNP, while those of BPA, MCBPA, DCBPA, and NP were lower than 1 (0.39–0.97). Such obvious difference in maternal transfer is probably due to their different affinities to plasma proteins, as exemplified by the correlation between EMR and the binding affinities to T4 transport proteins (TTR). This is the first report on the occurrence and maternal transfer of chlorinated derivatives of BPA and NP in human embryos and decidua