高效液相色谱-电喷雾质谱法测定土壤中的矮壮素残留

Determination of Chlormequat Residues in Soil by High Performance Liquid Chromatography-Electrospray Mass Spectrometry

研究建立了土壤中矮壮素残留的高效液相色谱-电喷雾质谱(HPLC-ESI-MS)检测方法。样品经甲醇-乙酸铵水溶液提取、离心及浓缩后,经反相色谱柱分离,采用高效液相色谱-电喷雾质谱检测,在选择离子监测模式(SIM)下以碎片离子m/z122.2进行外标法定量。土壤中矮壮素残留的检出限(S/N=3)为0.01mg/kg,定量限为0.05mg/kg;在0.01～1.0mg/L范围内峰面积与质量浓度的线性关系良好(r2>0.996)。在0.05、0.5和1.0mg/kg3个添加水平下,矮壮素的平均回收率范围为75.1%～87.2%,相对标准偏差小于10%。对矮壮素在土壤中消解动态的研究结果表明,其在土壤中的消解半衰期为4.47d。

An analytical method was developed for determination of chlormequat residues in soil.Chlormequat was extracted from the matrices by methanol-ammonium acetate solution and then analyzed by reversed phase HPLC with electrospray mass spectrometric detection.Mass spectral acquisition was realized by select ion monitoring of chlormequat cation.The limit of detection （LOD） was 0.01 mg/kg,and the limit of quantitation （LOQ） was 0.05 mg/kg.The linear range is 0.01～1.0 mg/kg and the correlation coefficient （r2） was more than 0.996.The average recoveries ranged from 75.1% to 87.2% for chlormequat in replicate sets of soil samples fortified with standard concentration of 0.05,0.5 and 1.0 mg/kg,and the relative standard deviation （RSD） were less than 10%.With the established method,the dissipation rate of chlormequat in soil was studied,showing a half-life of 4.47 d.