Determination of Rotenone Residue in Cabbage by LC-MS

A method for determination of rotenone residue in cabbage was established by LC-MS.Rotenone residue was extracted from sample with acetonitrile,cleaned up by ProElut Carbon/NH2 SPE to achieve sample preparation,and separated on the MGШ-C18 column using a mixture of acetonitrile and 0.1% formic acid solution(60∶40) as mobile phase.Determination was performed by using ESI+ and under the mode of SIM.Quantitative detection of ions at m/z 395,the retention time of rotenone was about 4.8 min.Linearities were held in the ranges of 0.001～1.000 mg/L with the correlation coefficient for 0.999 98.The average recoveries of rotenone in cabbage at the spiked amounts of 0.01、0.10、0.50 mg/kg were 70.5%～112.6%,and the relative standard deviation was lower than 20.9%(n=5).The limit of detectable amount(S/N=10) was 2.5×10-11 g.The accuracy and precision of this method could meet the detection requirements.