| A mixed mode solid phase extraction（SPE） coupled with ultra high pressure liquid chromatography（UPLC） was developed for the determination of seven aniline derivatives（ADs） in waste water by optimizing chromatographic analysis,SPE and nitrogen-blowing concentration.200 mL water sample was loaded onto MCX SPE cartridges with a flow rate of 5 mL/min,and ADs were immobilized on SPE column with 4 mL 2% formic acid.Before eluted with 4 mL methanol containing 2% ammonia,the column was cleaned up with 4 mL 25% methanol.The elute was concentrated to 1 mL by nitrogen blowing at 50 ℃,and filtered through a microfiltration membrane（0.22 μm,nylon）.The separation of ADs was performed on a BEH C18 column（2.1 mm×50 mm,1.7 μm） by gradient elution using methanol-50 mmol/L ammonium acetate.The UV detector was set at 250 nm.Under the optimal conditions,seven ADs were separated by baseline within 6.5 min.The calibration curves for seven ADs were linear in the range of 0.1-5.0 mg/L with correlation coefficients more than 0999.The method limits of detection（S/N=3） and limits of quantitation（S/N=10） were 0.10-0.50 μg/L and 0.33-1.67 μg/L,respectively.The recoveries of seven ADs at spiked levels of 0.2 μg and 1.0 μg were 52%-101% and 54%-96%,with RSDs of 2.2%-11.3% and 2.5%-9.0%,respectively.With the advantages of good anti-interference ability,rapidness and sensitivity,the method was suitable for the detection of ADs in waste water. |