Comparison of different detection methods.

LLE: Liquid-liquid extraction; SPE: Solid phase extraction; SPME: Solid phase micro-extraction; SDME: Single drop micro-extraction; DLLME: Dispersive liquid–liquid micro-extraction; HFLPME :Hollow fiber liquid-phase micro-extraction; MLLE: Micro liquid–liquid extraction; LPME: Liquid phase micro-extraction; PTV: A programmed temperature evaporizer inlet; HS: Headspace; IS-PCR-IC: A post-column reaction-ion chromatography analyzer (PCR-IC) with automated internal standardization (IS); PAEKI-CE-MS/MS: Pressure-assisted electrokinetic injection for on-line enrichment in capillary electrophoresis–mass spectrometry; GC-ECD: Gas chromatography coupled with electron capture detector; GC-MS: Gas chromatography coupled with mass spectrometry; LC-MS/MS: Liquid chromatography tandem mass spectrometry; HPLC-MS/MS: High performance liquid chromatography tandem mass spectrometry; UPLC-MS/MS: Ultra-performance liquid chromatography tandem mass spectrometry. THM4 include CF, BDCM, CDBM and BF; HAA5 include CAA, BAA, DCAA, DBAA and TCAA; HAA6 include CAA, BAA, DCAA, DBAA, TCAA and BCAA; HAA9 include CAA, BAA, DCAA, DBAA, TCAA, BCAA, BDCAA, CDBAA and TBAA.