| A method for the determination of chloramphenicol in cosmetics was developed using direct real time analysis-high resolution mass spectrometry.The sample was ultrasonically extracted with ethanol,then diluted 1∶1 by volume with water,and finally injected with a 12 Dip-it Samplers.The instrument parameter were optimized to obtain the sensitive and accurate determination for chloramphenicol.At a sample introduction rate of 0.3 mm/s,high intensity of ［M-H］-ions for chloramphenicol were observed in the negative ion and Full MS-PRM mode by utilization of high purity helium gas at 500 ℃.The calibration curve for chloramphenicol was linear in the range of 0-100 mg/L with a correlation coefficient of 0.998 4.The limit of quantitation(LOQ) of the method was 3.0 mg/kg.Recoveries for chloramphenicol at three spiked levels of 3.0,6.0,30 mg/kg were in the range of 70.2%-119%,with relative standard deviations(RSD) of 8.4%-17%.With its rapid analysis,simple pretreatment steps and low matrix interference,the method was suitable for the rapid determination of chloramphenicol in cosmetics. |