| A high performance liquid chromatography with fluorescence detector was developed for the simultaneous determination of four benzoxazole fluorescent whitening agents,i.e.FWA 135,FWA 367,FWA 368 and FWA 184 in plastic children's toys.The sample was crushed and pretreated with 20 mL acetonitrile-chloroform(6∶4,by volume) mixed solution by one step solvent extraction,then ultrasonically extracted at 40 ℃ for 30 min,and finally analyzed by HPLC with fluorescence detection.The extract was separated on a Waters SunFire C18 column by gradient elution with acetonitrile and water as mobile phases.The fluorescence excitation wavelength(Ex) was set at 360 nm,and the emission wavelength(Em) was 430 nm.Results showed that the calibration curves were linear(r2≥0.999 3) in the range of 1-100 μg/L for FWA 135,and 2-200 μg/L for the other three fluorescent whitening agents.The detection limits for FWA 135,FWA 367,FWA 368 and FWA 184 were 0.5,1,1 and 1 μg/L,respectively.The recoveries for four fluorescent whitening agents at three spiked levels of 0.1,0.4 and 2.0 mg/kg ranged from 84.2% to 106%,with relative standard deviations less than 10%.Ten kinds of childrens toys were tested,and four kinds of benzoxazole fluorescent whitening agents were detected.With the advantages of simple operation,good recovery and high precision,the method is applicable for the determination of the fluorescent whitening agents in various types of children's toys. |