The determination of bisphenol A (BPA) and/or bisphenol A diglycidyl ether (BADGE) in foods sold in Japanese markets and in water leached from six epoxy resin cans with similar diameters was carried out using high-performance liquid chromatography (HPLC) with electrochemical detection (LC/ECD), LC-mass spectrometric detection (LC/MS) and LC-tandem mass spectrometric detection (LC/MS/MS). BPA concentrations were 0-842 ng g(-1) for 48 canned foods, 0-14 ng g(-1) for 23 foods in plastic containers, and 0-1 ng g(-1) for 16 foods in paper containers. No BADGE was detected in three canned foods. There was no difference in leaching concentrations of BPA into glycine buffers at pHs 8 and 11, and water. The amounts of BPA leached into water from six epoxy resin cans held at 121 degrees C for 20 min were almost the same as the cans' contents and were much higher than the amounts leached from cans held at or below 80 degrees C for 60 min. The amount leached depended on the type of can, but not on the amount of BADGE leached from the cans. Considerably more BPA than BADGE leached to water from six cans. Two cans whose contents had high concentrations of BPA showed no BADGE leaching even at 121 degrees C, suggesting the different kinds of epoxy resin can linings from others. The results imply that the main source of human exposure to BPA is food from cans with linings that contain high percentages of BPA as an additive or an unforeseen contaminant.

Bisphenol A (BPA) values were compared in plasma of hemodialysis patients and in recycling solvents using LC/MS, LC/electrochemical detector (ECD), and enzyme linked immunosorbent assay (ELISA). BPA values in the plasma and the solvent were 0-8.4 ng/ml and 0-0.8 ng/ml for LC/ECD, 0-4.9 ng/ml and 0-0.8 ng/ml for LC/MS, and 0-15.5 ng/ml and 0-3.1 ng/ml for ELISA, respectively. There was no significant difference among BPA values both in the plasma and the solvents using three methods. Single correlation coefficients between LC/ECD and LC/MS, LC/ECD and ELISA, and LC/MS and ELISA were, respectively, 0.373 (p < 0.002), 0.347 (p < 0.002), and 0.945 (p < 0.001) in the plasma (n = 68-109) and 0.916 (p < 0.001), 0.431 (p > 0.05), and 0.332 (p > 0.05) in the solvents (n = 19). An unknown substance present in the plasma of patients but not healthy volunteers influenced the LC/ECD values of plasma repeated freezing and thawing. The results indicate that LC/MS and ELISA are appropriate for BPA analysis in plasma and both LC/MS and LC/ECD in the recycling solvents and handling with plasma before analysis is important to the analysis of BPA in patients' plasma using LC/ECD.

No abstract

A multiplex PCR (M-PCR) method was developed for the detection of DNAs of plant and three allergenic substances (wheat, buckwheat, and peanut) in foods. Genomic DNAs were extracted from allergenic substances with a commercial ion-exchange type kit. Four primer pairs suitable for the specific detection of plant DNA were designed to establish a M-PCR method detecting simultaneously the specific DNAs of plant and allergenic substances. Our four designed primer pairs and the primer pair described in the Japanese o$cial method were applied to the specific detection of plant DNA. A primer pair of Plant01-5῎ and Plant01-3῎ (amplicon size; 161 bp) was the most suitable for the specific detection of plant DNA. M-PCR was performed to detect the specific DNAs of allergenic substances using four primer pairs, a pair of Plant01-5῎ and Plant01-3῎, and three pairs for allergenic components described in the Japanese o$cial method. The four specific PCR bands were simultaneously amplified from genomic DNAs of allergenic substances. The proposed method is simple, rapid and inexpensive.

No abstract