Preparation of 4,4'-(1-[(2)H6]methylethylidene)bis-[2,3,5,6-(2)H4]phenol and its application to the measurement of bisphenol A in beverages by stable isotope dilution mass spectrometry.
The preparation of 4,4'-(1-[(2)H6]methylethylidene)bis-[2,3,5,6-(2)H4]phenol, bisphenol A-d14, was achieved in excellent yield by reaction of [2H6]acetone with [2H6]phenol in the presence of deuterium chloride. The product thus obtained was shown by mass spectroscopy to be a mixture of the 2H14, 2H13 and 2H12 isotopomers in the relative proportions of 82.3:16.2:1.5, respectively. An isotope dilution gas chromatography-mass spectrometric method using bisphenol A-d14 as an internal standard was developed to measure the level of bisphenol A in beverages. The procedure involves extracting bisphenol A into dichloromethane, and then purifying the analyte by back extraction into dilute aqueous sodium hydroxide. Conversion of bisphenol A and its internal standard, bisphenol A-d14, to their corresponding O-bis(trifluoroacetyl) derivatives by treatment with trifluoroacetic anhydride gave compounds with good chromatographic properties and whose mass fragmentometry is such that loss of M-CH3 and M-C2H3 are the base peaks in the mass spectra of the analyte and internal standard, respectively. Quantification of bisphenol A was achieved by comparing the area of the M-15 ion to that of the corresponding ion of bisphenol A-d14. The characteristics of our assay are: an analyte recovery of better than 95%, a root mean square signal-to-noise ratio of 79:1 for 1.7 pg on column and an inter-assay RSD of better than 4% (n=5).
Food Science Australia, A Joint Venture of CSIRO and Afisc, North Ryde, NSW.
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D001559:Benzhydryl Compounds; D002138:Calibration; D003903:Deuterium; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D010636:Phenols / Q000032:analysis*; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D003903:Deuterium; D010636:Phenols; C006780:bisphenol A; D000098826:Bisphenol A Compounds