Study of possible association between endometriosis and phthalate and bisphenol A by biomarkers analysis.

Endocrine disrupting chemicals (EDCs) such as phthalates and bisphenol A (BPA) are substances that may interfere with the actions of endogenous hormones and may be associated with estrogen-related diseases such as endometriosis. This paper describes a case-control study to evaluate the relationship between endometriosis and phthalates and BPA exposure, through biomarkers analysis in urine. The biomarkers of exposure analyzed were metabolites mono-methyl phthalate, mono-isobutyl phthalate (MiBP), mono-butyl phthalate, mono-cyclohexyl phthalate, mono-(ethylhexyl) phthalate, mono-isononyl phthalate, mono-octyl phthalate (MOP), mono-benzyl phthalate and BPA. Urine samples were collected from women aged 18-45 years old. The Study group (n = 30) and Control group (n = 22) were composed of women using as criteria confirmation of endometriosis by videolaparoscopy surgery with histological diagnosis and the absence of the disease, respectively. The analytical method used liquid phase microextraction with determination by gas chromatography coupled to mass spectrometry. The concentrations of biomarkers were adjusted by the creatinine concentration in urine samples of the two groups. The values obtained for the Study Group were compared with the values obtained for the Control Group. The chi-square test and Odds Ratio were used to compare dichotomized phthalate metabolites and BPA metabolite by endometriosis. All nine metabolites were found in different concentrations in the urine samples in both groups The phthalate metabolites that had the highest concentrations, were MOP and MiBP, in which the values of 670 µg g-1 and 560 µg g-1, respectively. The relationship between endometriosis and the all grouped metabolites was evaluated, but was not statistically significant with a 95% CI [X2 (df = 1) = 1.471; p = 0.225]. However, odds ratio (95% confidence interval - CI) for MiBP, which was found at relatively high concentrations in the samples, by endometriosis was 1.929 (0.507-7.332). The food habits and gynecologic history were evaluated and no difference was found between groups. Although no evidences of causal link was found, this study contributes to show that other analysis must be done for evaluating the association between endometriosis and compounds suspected of being EDC.

Magnetic N-doped carbon nanotubes: A versatile and efficient material for the determination of polycyclic aromatic hydrocarbons in environmental water samples.

This paper describes a new, efficient and versatile method for the sampling and preconcentration of PAH in environmental water matrices using special hybrid magnetic carbon nanotubes. These N-doped amphiphilic CNT can be easily dispersed in any aqueous matrix due to the N containing hydrophilic part and at the same time show high efficiency for the adsorption of different PAH contaminants due to the very hydrophobic surface. After adsorption, the CNT can be easily removed from the medium by a simple magnetic separation. GC/MS analyses showed that the CNT method is more efficient than the use of polydimethylsiloxane (PDMS) with much lower solvent consumption, technical simplicity and time, showing good linearity (range 0.18-80.00 µg L(-1)) and determination coefficient (R(2) > 0.9810). The limit of detection ranged from 0.05 to 0.42 µg L(-1) with limit of quantification from 0.18 to 1.40 µg L(-1). Recovery (n=9) ranged from 80.50 ± 10 to 105.40 ± 12%. Intraday precision (RSD, n=9) ranged from 1.91 to 9.01%, whereas inter day precision (RSD, n=9) ranged from 7.02 to 17.94%. The method was applied to the analyses of PAH in four lake water samples collected in Belo Horizonte City, Brazil.