对虾中残留氯霉素的负化学源GC/MS分析

Determination of chloramphenicol residues in prawns by GC- NCI- MS

建立了对虾中残留氯霉素(CAP)负化学源(NCI)的GC/MS分析方法。样品中CAP用乙酸乙酯提取,脂肪用正己烷去除,过聚苯乙烯型DiaionHP-20吸附层析小柱纯化样品,BSTFA-TMCS衍生后用NCI源选择m/z为466的特征离子为目标离子,在SIM模式下进行GC/MS分析。被检测CAP质量浓度在5～500μg/L内,方法的线性关系良好,相关系数为0.9988。方法的最低检测限达到0.037μg/kg。当空白样品CAP水平为1～100μg/kg时,平均回收率达71.33%～95.29%,相对标准偏差为1.73%～7.45%。用此方法对市场上销售的人工养殖南美白对虾(Penaeusvan namei)肌肉样品进行测定,结果显示氯霉素残留量为(0.154±0.008)μg/kg,而野生脊尾白虾(Palaemoncarincauda)肌肉样品中未检出CAP残留。

The determination of chloramphenicol in prawns was established by gas chromatography-mass spectrometry with negative chemical ionization (GC-NCI-MS). Chloramphenicol was extracted with ethyl acetate and partitioned with n-hexane to remove lipids.Cleanup was performed on a Diaion HP-20 column, and the recovered chloramphenicol was derived with BSTFA-TMCS and analyzed in selective ion monitoring (SIM) mode using m/z 466 as the characteristic ion. The linear range was very good from 5 to 500 μg/L and relative coefficient was 0.998 8.The detection limit was down to 0.037 μg/kg. The average recovery rates were 71.33%-95.29% when 1-100 μg/kg chloramphenicol standards were spiked into the zero shrimp sample, and the RSDs were 1.73%-7.45%. The chloramphenicol residues in the coltured Penaeus vannamei muscle obtained from market was (0.154±0.008)μg /kg and no chloramphenicol residue was detected in the Palaemon carincauda muscle.