对鱼肉样品中有机氯、有机磷和拟除虫菊酯3类14种残留农药的气相色谱-负化学离子源/质谱(GC-NCI/MS)的测定方法作研究.鱼肉样品以Florisil硅藻土与中性氧化铝作为基质固相分散剂和以乙酸乙酯作为提取剂,经超声辅助提取和浓缩后,以2,2′,4,5′,6-五氯联苯(PCB-103)为内标物,采用GC-NCI/MS的选择离子监测方式和空白基体匹配校准曲线法进行定性与定量分析.农药(溴氰菊酯及氯菊酯除外)的检出限(3S/N)均小于1.0 μg·kg-1,线性范围为10~800 μg·kg-1,当鱼肉样品的加标量为10,50,200 μg·kg-1时,平均回收率在66.6%~102.0%之间,相对标准偏差(n=6)小于12%.

Residues of 14 pesticides of 3 categories,i.e.,the organochloro-compounds,the organophospho-compound and compounds of analogous dalmatian chrysanthemum,were determined by hyphenation of GC and MS with negative chemical ionization (abbreviated as GC-NCI/MS).Sample of fish was smashed and dispersed with Florisil diatomite and neutral aluminum oxide.The semi-pasty mixture obtained was then extracted with ethylacetate by ultrasonic agitation.After concentration by N2-blowing and addition of 2,2′,4,5′,6-pentachlorobiphenyl (PCB-103) solution as internal standard,the solution was used for GC-NCI/MS determination of the 14 pesticides,with SIM mode.Method of calibration curves with matrix matching was adopted in the qualitative and quantitative analysis.Range of linearity found was from 10 to 800 μg·kg-1 for all of the 14 pesticides,and their detection limits (3S/N) were all less than 1.0 μg·kg-1 (with exception of permethrin and deltamethrin).Recovery was tested by addition of 10,50 and 200 μg·kg-1 of pesticide standards to fish samples,giving values of recovery in the range of 66.6%-102.0%,with values of RSD′s (n=6) less than 12%.