A high performance liquid chromatography (HPLC) method was developed for the determination of bisphenol A (BPA) that had migrated into canned fruit and vegetables. BPA was extracted with acetonitrile from the solid portion of canned food, and with an OASIS HLB cartridge from the aqueous portion, respectively. Both extracts were cleaned up on a Florisil cartridge. The HPLC separation was carried out on a Wakosil II 3C18 RS column (4.6 x 150 mm) with acetonitrile-water (40:60, v/v) as a mobile phase with a flow rate of 0.8 ml/min. BPA was detectable by UV detector at 228 nm and determined with the similarity of chromatographic peak spectrum by multiwavelength detector (similarity index was 0.99 or above). The quantification limits were 10 ng/g for the solid portion and 5 ng/ml for the aqueous portion, respectively. BPA was mainly detected in the solid portion of canned food and found at the maximum level of 11 micrograms per can. To verify migration into the solid portion of canned food, a partitioning experiment was carried out.

Abstract. Epigenetic alteration is an emerging paradigm underlying the long-term effects of chemicals on gene functions. Various chemicals, including organophosphate insecticides and heavy metals, have been detected in the human fetal environment. Epigenetics by DNA methylation and histone modifications, through dynamic chromatin remodeling, is a mechanism for genome stability and gene functions. To investigate whether such environmental chemicals may cause epigenetic alterations, we studied the effects of selected chemicals on morphological changes in heterochromatin and DNA methylation status in mouse ES cells (ESCs). Twenty-five chemicals, including organophosphate insecticides, heavy metals and their metabolites, were assessed for their effect on the epigenetic status of mouse ESCs by monitoring heterochromatin stained with 4′,6-diamino-2-phenylindole (DAPI). The cells were surveyed after 48 or 96 h of exposure to the chemicals at the serum concentrations of cord blood. The candidates for epigenetic mutagens were examined for the effect on DNA methylation at genic regions. Of the 25 chemicals, five chemicals (diethyl phosphate (DEP), mercury (Hg), cotinine, selenium (Se) and octachlorodipropyl ether (S-421)) caused alterations in nuclear staining, suggesting that they affected heterochromatin conditions. Hg and Se caused aberrant DNA methylation at gene loci. Furthermore, DEP at 0.1 ppb caused irreversible heterochromatin changes in ESCs, and DEP-, Hg-and S-421-exposed cells also exhibited impaired formation of the embryoid body (EB), which is an in vitro model for early embryos. We established a system for assessment of epigenetic mutagens. We identified environmental chemicals that could have effects on the human fetus epigenetic status. Key words: DNA methylation, Embryoid body, Epigenetic mutagens, ES cells, Heterochromatin (J. Reprod. Dev. 57: [507][508][509][510][511][512][513][514][515][516][517] 2011) any chemicals have been widely used in the household, agricultural and urban environment, and there are various environmental chemicals in the fetal growth environment: organophosphate insecticides (chlorpyrifos), perfluorooctane sulfonate (PFOS), di(2-ethylhexyl)phthalate (DEHP), elements of tobacco smoke (nicotine and cotinine) and heavy metals (lead (Pb), cadmium (Cd) and mercury (Hg)) [1][2][3][4][5]. Hg exposure occurs in the daily intake of rice in China [6]. Prenatal exposure to environmental chemicals such as organophosphate insecticides, tobacco smoke, heavy metals and perfluorinated compounds (PFCs) is associated with fetal growth restriction and low birth weight of infants [7][8][9][10]. The concentration of chemicals detected in the fetal environment is, however, relatively low (around 0.1-10 ppb level) and far from the levels reported in pharmacological studies. Such a low concentration may accumulate in the fetus and placenta and affect fetal growth [11][12][13][14], and alternatively, some chemicals may have long-term effects on gene functions and stability even at a low concentration ...

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Quantitative methods using liquid chromatography coupled with tandem mass spectrometry were developed for seven kinds of aminoglycoside antibiotics in kidney and muscle tissues. Mass spectral acquisition was performed in the positive-ion mode by applying multiple reaction monitoring. Liquid chromatographic separation employed a ZIC-HILIC column (SeQuant) for hydrophilic interaction chromatography. Extraction of the aminoglycosides was performed using liquid extraction with a phosphate buffer containing trichloroacetic acid, followed by a solid-phase clean-up procedure on a weak cation-exchange column with carboxypropyl (CBX) SPE cartridge (Mallinckrodt Baker). The limits of quantification were 25 ng g(-1) for gentamicin, 50 ng g(-1) for spectinomycin, dihydrostreptomycin, kanamycin and apramycin, and 100 ng g(-1) for streptomycin and neomycin. These are well below the maximum residue limits set by the Codex Alimentarius Commission. The recoveries of all compounds from all tissues fortified at the level of quantification limits of 500 and 1000 ng g(-1) were >70%, and the variability (relative standard deviation) was generally <12%.