Non-target Screening Analysis of Volatile Organic Compounds in Drinking Water by Headspace-solid Phase Microextraction Gas Chromatography-Mass Spectrometry

Abstract

Abstract A non-target screening analytical method for volatile organic compounds (VOCs) in drinking water by headspace-solid phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS) was established. The operating parameters of HS-SPME were optimized by the peak number and area of extract. The optimal working conditions of four different extraction fibers (100 μm PDMS, 65 μm PDMS/DVB, 85 μm PA and 75 μm CAR/PDMS) were investigated, including incubation time, extraction time, extraction temperature, NaCl concentration and desorption time. The oil-water partition coefficient and the number of the substances extracted by the four fibers were compared, and the results showed that the substances extracted by 100 μm PDMS was the least, and these compounds also could be extracted by the other three fibers, so the 100 μm PDMS could be replaced by the other fibers. The three optimized fibers were used for the non-target screening of two tap water samples in Wuhan (the source water came from the Yangtze river and the Han river, respectively), and the substances with more than 70% match degree from NIST library were selected for analysis. The results showed that 35 substances identified in the tap water sample from the Han River, 34 substances in the tap water from the Yangtze River, and there were 18 found in common. Comparing the types of substances screened in the two water samples, it was found that the esters were the most abundant substances, followed by the aldehydes and phenols. No organic solvents were used in this method, which was environmentally friendly, and it could be used to screen and analyze the VOCs in tap water.