液相色谱-串联质谱法测定鳗鱼中链霉素和双氢链霉素残留量

Determination of streptomycin and dihydrostreptomycin residues in eel by liquid chromatography tandem mass spectrometry

建立了不使用离子对试剂,液质联用技术检测鳗鱼中链霉素和双氢链霉素残留量的检测方法。样品经三氯乙酸溶液提取,碱性氧化铝快速净化,弱阳离子交换柱固相萃取,CAPCELL PAK ST柱分离。链霉素和双氢链霉素检出限为1.5μg/kg,在10.0-500 ng/m L质量浓度范围内链霉素和双氢链霉素呈线性相关,相关系数为0.9999和0.9994,回收率在78.3%-105.9%之间,相对标准偏差在3.1%-6.6%之间。方法采用碱性氧化铝基质分散固相萃取,除去样液中油脂同时也降低样液中酸的浓度,进而降低固相萃取上样液中碱金属离子强度,提高了链霉素和双氢链霉素残留检测的绝对回收率。

A method for the determination of streptomycin and dihydrostreptomycin residues in eels by liquid chromatography tandem mass spectrometry was developed,and no ion pair reagent was used in the method.Streptomycin and dihydrostreptomycin were extracted with 5% trichloroacetic acid solution,after oscillation extraction and centrifugation,alumina-B was added into the supernatant liquid,vortex mixing,and centrifugated supernatant fluid was adjusted p H to 7. 5 with sodium hydroxide solution. Supernatant fluid was cleansed with a PWC solid-phase extraction column,and SPE was eluted with 10% formic acid aqueous and acetonitrile（ V / V,2∶ 3）. All the eluent was mixed and filtered. The sample solution was separated on a CAPCELL PAK ST column with LC-MS / MS assay. Detection limits of streptomycin and dihydrostreptomycin were 1. 5 μg / kg in the eels.The linear ranges for streptomycin and dihydrostreptomycin concentrations were 10. 0 - 500 ng / m L,respectively,and the correlation coefficients were 0. 9999 and 0. 9994. The recoveries of methods were between78. 3% and 105. 9%, relative standard deviations were 3. 1% - 6. 6%. Matrix dispersive solid-phase extraction with alumina-B could remove grease in the sample solution to reduce acid concentration in sample solution,further reduce alkali metal ion strength in sample solution before the solid phase extraction. Ultimately the absolute recoveries of streptomycin and dihydrostreptomycin residue detection were improved,and the method was of high sensitivity and simple operation.