Assessment of ionic liquid stationary phases for the determination of polychlorinated biphenyls, organochlorine pesticides and polybrominated diphenyl ethers.

Five ionic liquid stationary phases were tested for the gas chromatographic (GC) analysis of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). In comparison with a non-polar DB5MS stationary phase, which is normally used in single-column GC for these compounds, all phases tested provided a different elution pattern. Mono-ortho substituted PCBs showed longer retention times, whereas di-ortho PCB congeners eluted earlier. These different patterns provide a potential for use of these columns for single-column PCB analysis, but in particular for use in comprehensive two-dimensional GC (GC×GC). The SLB-IL111 phase showed the most striking differences in elution of PCBs compared to DB5MS. The analysis of OCPs was hindered by adsorption and on-column degradation with most of the phases tested. Additional experiments with polybrominated diphenylethers (PBDEs) also revealed serious degradation of most of the congeners. Only the SLB-IL60 column showed a better performance for OCPs, in combination with a relatively low bleeding.

Dietary and sociodemographic determinants of bisphenol A urine concentrations in pregnant women and children.

Bisphenol A (BPA) exposure during early life may have endocrine-disrupting effects, but the dietary and sociodemographic predictors of BPA exposure during pregnancy and childhood remain unclear. Our aim was to evaluate the correlations between, and sociodemographic and dietary predictors of, serial urinary BPA concentrations measured during pregnancy and childhood in a Spanish birth cohort study. BPA was measured in two spot urine samples collected from 479 women during the first and third trimester of pregnancy and in one urine sample from their 4-year old children (n=130). Average dietary intakes were reported in food frequency questionnaires during the first and third pregnancy trimester and at age 4years. Multivariate mixed models and linear regression models were used to estimate associations between sociodemographic and dietary factors and BPA concentrations. A small, but statistically significant correlation was found between serial maternal BPA concentrations measured during pregnancy (r=0.17). Pregnant women who were younger, less-educated, smoked, and who were exposed to second-hand tobacco smoke (SHS) had higher BPA concentrations than others. BPA concentrations were also higher in children exposed to SHS. High consumption of canned fish during pregnancy was associated with 21% [GM ratio=1.21; 95%CI 1.02, 1.44] and 25% [GM ratio=1.25; 95%CI 1.05, 1.49] higher urinary BPA concentrations in the first and third pregnancy trimester, respectively, compared to the lowest consumption group. This study suggests that canned fish may be a major source of BPA during pregnancy in Spain, a country of high canned fish consumption. Further evaluation of specific BPA exposure sources in the sociodemographic group of younger women who smoke, are exposed to SHS, and have a low educational level is needed. Studies identifying sources of exposure would benefit from repeat BPA measurements and questionnaires specifically focused on dietary and packaging sources.