串联双柱固相萃取-液相色谱-串联质谱法测定番茄酱中链霉素和双氢链霉素残留量

建立了同时测定番茄酱中链霉素和双氢链霉素残留量的串联双柱净化-液相色谱-串联质谱方法。样品中的残留物用磷酸盐缓冲液(pH 4)提取,经分散固相萃取净化和串联双柱固相萃取净化后,用极性色谱柱在梯度洗脱条件下分离待测物,采用正离子电喷雾离子源(ESI+)在多反应监测(MRM)扫描模式下进行测定,外标法定量。链霉素和双氢链霉素在0.01～0.2 mg/L质量浓度范围内线性关系良好,相关系数(r)大于0.999。链霉素和双氢链霉素的定量限均为0.02 mg/kg,回收率为71%～101%,相对标准偏差为2.3%～15%。该方法操作简便,净化效果好,灵敏,准确,适用于检测和分析番茄酱及其制品中链霉素和双氢链霉素残留量。

Determination of streptomycin and dihydrostreptomycin residues in tomato paste by tandem dual solid phase extraction column-liquid chromatography-tandem mass spectrometry

The method was specifically developed for the simultaneous determination of streptomycin and dihydrostreptomycin residues in tomato paste by tandem dual solid phase extraction (SPE) column cleanup-liquid chromatography-tandem mass spectrometry. The residues were extracted from the samples with phosphate buffer solution (pH 4). The cleanup was performed by the way of dispersive solid phase extraction and tandem dual solid phase extraction column. The polar chromatographic column was used to complete the separation of the analytes under gradient elution and the analytes were detected in multiple reaction monitoring (MRM) mode via positive electrospray ionization (ESI +). The external standard calibration curves were used for the quantification. The linear ranges were from 0.01 to 0.2 mg/L with a good linear relationship (r > 0.999) for streptomycin and dihydrostreptomycin. The limit of quantification (LOQs) was 0.02 mg/kg for the both analytes. The recovery range was from 71% to 101% with the relative standard deviations (RSDs) between 2.3% and 15%. It was indicated that this method is accurate, easier, more sensitive, and has a better purification effect in the monitoring and analysis. The method is accurate and specific to monitor and analyze of streptomycin and dihydrostreptomycin residues in tomato paste and its products.