| A confirmatory method using ultrahigh pressure liquid chromatography（UPLC） coupled with tunable ultraviolet detector（TUV） was developed for the determination of trace levels of tetracyclines,including chlortetracycline（CTC）,doxycycline（DC）,4 epitetracycline（ETC）,4 epichlortetracycline（ECTC）,4 epianhydrotetracycline（EATC）,oxytetracycline（OTC）,tetracycline（TC） and anhydrotetracycline（ATC）,in environmental water samples.The rare earth metal La ions were used as chelating agent to form a hydrophobic complex compound with TCs.Temperature induced ionic liquids dispersive liquid-liquid microextraction（DLLME）was used to concentrate the target compound.Effects of experimental conditions,including the kinds and amounts of ionic liquids,heating temperature,time of complexation and extraction,concentration of Triton X 114 and pH value，on extraction efficiencies were investigated.Under the optimum conditions,the calibration curves were linear in the range of 10-200 μg?L-1 for ETC,TC,DC and ATC,and 01-200 μg?L-1 for ECTC,CTC and EATC,and 10-200 μg?L-1 for OTC,respectively,with correlation coefficients（r2） more than 099.The limits of detection（LODs） ranged from 003 μg?L-1 to 579 μg?L-1,and the limits of quantitation（LOQs） were in the range of 009-191 μg?L-1.The spiked recoveries of eight target compounds in river water,fishpond water and leaching water of the pig farm soil were achieved in the range of 63%-96%,59%-94% and 55%-86%,respectively.The investigation results of environmental water samples in Beijing showed that 214 μg?L-1CTC and 009 μg?L-1 ECTC were detected in waste water from hoggery and no target compounds were found in the river water and fishpond water samples.As a result,this method could be applied in the rapid and convenient determination of eight tetracycline antibiotics in real environmental water samples. |