Levels of bisphenol A and bisphenol F in canned foods in Iranian markets

Bisphenol A and bisphenol F are chemical substances widely used in industry as monomers in the production of epoxy resins and polycarbonates, and as antioxidants in PVC. Epoxy resins are used as inner surface coating of food and beverage cans. The contamination of cans' content by bisphenol A and bisphenol F may pose a serious threat to human because of their estrogenic activity. In this study, the concentration of bisphenol A and bisphenol F in 48 cans of different kinds of foods [corn, tomato paste, stew and tuna fish] were determined by gas chromatography-mass spectrometry after solvent extraction with acetonitrile and preconcentration by headspace-solid-phase microextraction [HS-SPME]. Quantitative analysis was carried out based on spiked calibration samples and analyses were performed for each sample in triplicate. Bisphenol F was not detected in any of the canned foods with detection limits of 0.10 micro g/kg. There were significant differences among the mean concentrations of bisphenol A in all kinds of canned foods. The mean concentrations of bisphenol A increased significantly all samples after heating in [ANOVA p<0.05 and Kruskal-Wallis test p<0.05]; also tuna fish samples were found to be probably the most polluted groups in this study

Survey on degradation rates of trichloroethylene in aqueous solutions by ultrasound

Sonochemical degradation of different compounds such as chlorinated aliphatic hydrocarbons is one of the recent advanced oxidation processes and it may be effective for removing low concentration organic pollutants from aqueous streams. Trichloroethylene [TCE] is one of these compounds that is mainly used as a degreaser. Important studies about TCE sonolysis have been focused at millimolar levels and natural pH, but in this study the ultrasonic degradation of TCE at different micromolar initial concentrations [30, 300 and 3000 micro g/L] and 4 different initial pH with a 35 kHz frequency was investigated. Furthermore, the degradation of TCE by ultrasound with different concentrations of hydrogen peroxide at pH= 7 was also performed. Gas chromatography with FID detector was used for analyses of TCE. Results showed that the degradation of TCE increased with decrease in the initial concentration of TCE from 3000 to 30 micro g/L at all initial pH. Initial pH of solution and different concentrations of H[2]O[2] did not affect significantly the TCE destruction

Determination of urinary concentrations of organic oxygenates in urban workers

Methyl tert-butyl ether, ethyl tert-butyl ether and tert-amyl methyl ether are oxygenated compounds added to gasoline to enhance octane rating in replacement of alkyl-lead compounds. In the present study the excretion of urinary methyl tert-butyl ether, ethyl tert-butyl ether and tert-amyl methyl ether were evaluated as biomarkers of exposure to gasoline. With this aim, 10 policemen engaged in traffic control, 10 gas station workers and ten occupationally non-exposed persons were investigated. Spot urine samples were obtained prior to and at the end of the work shift from each subject. The urinary levels of oxygenated ethers were determined by using head-space gas chromatography and mass spectrometry detection. There were significant differences among the mean urinary concentrations of methyl tert-butyl ether in pre-shift samples of gas station workers [1193 ng/L], policemen [734 ng/L] and occupationally non-exposed persons [49 ng/L]. The mean urinary concentrations of methyl tert-butyl ether and tert-amyl methyl ether differed significantly among post-shift samples of gas station workers [16636 and 8655 ng/L], policemen [14458 and 1472 ng/L] and occupationally non-exposed persons [324 and 59 ng/L] [ANOVA: p<0.05 and Kruskal-Wallis test: p<0.05]. There was a significant difference in methyl tert-butyl ether concentrations between job categories [p<0.05 by ANOVA and Kruskal-Wallis test], and gas station workers and policemen were found to be probably the most exposed groups in this study