Simultaneous Determination of Bisphenol A and 9 Alkylphenols in Environmental Water by Gas Chromatography-Mass Spectrometry with Solid Phase Extraction and Derivatization

A method for the simultaneous determination of bisphenol A (BPA) and 9 C4-C9 alkylphenols (APs, including 4-tert-butylphenol, 4-n-butylphenol, 4-n-pentylphenol, 4-n-hexylphenol, 4-tert-octylphenol, 4-n-heptylphenol, nonylphenol, 4-n-octylphenol and 4-n-nonylphenol) in environmental water by gas chromatography-mass spectrometry with solid phase extraction and derivatization was proposed. Water sample (500 mL) was adjusted pH to less than 2 with 50%(φ) hydrochloric acid solution, passed through solid phase extraction membrane with styrene/divinylbenzene polymer as adsorbent at the rate of 50 mL·min^-1, and eluted with 5 mL of acetone and 10 mL of dichloromethane. The eluate was collected, and 1 mL of n-hexane was added. The mixture was dehydrated with 10 g of anhydrous sodium sulfate, and concentrated to about 0.5 mL by rotary evaporator. The concentrated solution was transferred to 1 mL-volumetric flask. The concentration bottle was washed with a small amount of dichloromethane, and the washing liquid was combined into the volumetric flask. Then 100 μL of internal standard mixed solution and 100 μL of derivative reagent were added successively, and the volume was made up to 1 mL with dichloromethane. The targets were derived at room temperature for 1 h. The targets in the above solution were separated by gas chromatograph with programmed temperature and programmed pressure, determined by mass spectrometer with selective ion monitoring mode, and quantified by internal standard method. As shown by the results, the linear ranges of standard curves of BPA and 9 APs were 5.000-500.0 μg·L^-1, with detection limits in the range of 0.002-0.006 μg·L^-1. RSDs (n=6) of the determined values of the targets in the blank water samples were in the range of 1.2%-15%. This method was applied to the analysis of surface water, sanitary sewage and industrial wastewater, in which nonylphenol and BPA were detected, and 4-tert-octylphenol was detected in the surface water and sanitary sewage, with detection amounts in the range of 0.005-0.657 μg·L^-1. The other APs were not detected, and the spiked recoveries of BPA and 9 APs in the actual samples were in the range of 73.4%-125%.