液相色谱-串联质谱法快速测定食品中的乌洛托品

Rapid determination of methenamine in foods by liquid chromatography-tandem mass spectrometry

建立测定乌洛托品的高效液相色谱-串联质谱法,用于快速监测食品中违法添加的乌洛托品。食品中乌洛托品经无水硫酸钠干燥脱水,乙腈提取后,采用梯度洗脱,SCX色谱柱分离,在电喷雾正离子模式下,多反应监测模式进行检测,外标法定量。乌洛托品在1～1 000μg/L浓度范围线性良好,相关系数为0.998 8,方法的检出限为0.2μg/kg,定量限为1.0μg/kg,加标回收率在52.6%～118%,相对标准偏差小于10.2%。本方法快速、准确,特异性强,灵敏度高,样品前处理简便易行,分析周期短,适合大量样品的测定。

A method of liquid chromatography-tandem mass spectrom- etry（LC--MS/MS） was developed to monitor methenamine which il- legally added in foods. Anhydrous sodium sulfate was used for drying and dehydration, and the solution of acetonitrile was used for extrac- ting methenamine. Then, a strong cation exchange（SCX） was ap- plied to separate target compound with gradient elute. The target compound was detected by Multiple Reaction Monitoring（MRM） at electro spray positive ionization（ESIq-） mode. The external standard method was adopted to quantify. The calibration curves showed good linearity for target compound with the detection range of 1 ~ 1000 pg/L. Correlative coefficient was 0. 998 8, the method of limits of deteetion（LOD） and the method of limits of quantitation（LOQ） were respectively 0.2 μg/kg and 1.0μg/kg, respectively. The spiked re- coveries in foods ranged 52. 6% from 118% with RSDs less than10.2%. This proposed method was rapid, accuracy, strong specifici- ty, high sensitivity. Pretreatment was easy to operate and satisfied with fast speed. The conclusion in this study showed it is suitable for the quantitative determination methenamine in foods.