Determination of 16 Typical Chlorinated Persistent Organic Pollutants in Groundwater by Gas Chromatography-High Resolution Mass Spectrometry

9 kinds of organochlorine pesticides (α-HCH, β-HCH, γ-HCH, δ-HCH, hexachlorobenzene, p,p′-DDE, p,p′-DDD, o,p′-DDT and p,p′-DDT) and 7 kinds of polychlorinated biphenyls (PCB 28, PCB 52, PCB 101, PCB 118, PCB 138, PCB 153 and PCB 180) were the target compounds of national ground water quality investigation. Until now, the low sensitivity of Gas Chromatography with Electron Capture Detector (GC-ECD) and Gas Chromatography-Mass Spectrometry/Selected Ion Monitoring (GC-MS/SIM) technique have been applied to monitor the quality of ground water, however, these analysis methods are unable to monitor trace and ultra-trace the persistent organic pollutants targeted in ground water. In this paper, a high sensitivity analysis method of the target compounds in groundwater by solid phase disk extraction coupled with Gas Chromatography-High Resolution Mass Spectrometry (GC-HRMS) is described. The detection limits for the target compounds were 0.10-0.20 ng/L, the recovery with standards were 61.9%-93.3% and RSD (n=5) were 2.41%-20.0%. The method was applied for detection of the target compounds in groundwater using samples from two different areas of China. The analytical results show that no PCBs were detected in any of the samples, but two water samples may be contaminated with a new γ-hexachlorocyclohexane emission source according to the detection of α-hexachlorocyclohexane and γ-hexachlorocyclohexane and their residual concentration ratios.