高效液相色谱串联质谱法测定乳粉中低聚果糖

摘要

建立了测定乳粉中低聚果糖(蔗果三糖、蔗果四糖、蔗果五糖、蔗果六糖)的高效液相色谱串联质谱(HPLC-MS/MS)检测方法.乳粉样品用乙醇-水提取,上清液稀释后,采用XBridge TM Amide(3.5μm,4.6 mm×150 mm)柱,以乙腈-氨水溶液为流动相进行洗脱,电喷雾质谱负离子(ESI-),多反应监测(MRM)模式检测,外标法定量.该方法在0.5~20 mg/L范围线性良好(r>0.9990,检出限最低为0.022 mg/kg).分别在样品中添加标准物质1、5、10 mg/kg进行回收率实验,方法的回收率范围为90.8%~95.8%,相对标准偏差为3.6%~9.0%(n=6).该方法样品前处理简单、快速,分析时间短,灵敏度、准确度和精密度均满足乳粉中低聚果糖的检测要求.%A method was developed for the determination of fructo-oligosaccharides (FOS) in milk powder by High Performance Liquid Chromatography Tandem Mass Spectrometry (HPLC-MS/MS). The samples were extracted by ethanol-water mixed solution, and then centrifugated. Chromatographic separation was achieved on XBridge TM Amide column (3.5μm, 4.6 mm×150 mm). The mobile phase consisted of acetonitrile-ammonia solution, and then analyzed by using HPLC-MS/MS in multiple reaction monitoring (MRM) mode on negative electrospray ionization (ESI-). External standard method was used to determine the residue contents with a good linear relationship of 0.5~20 mg/L (r>0.9990). The limit of quantification (LOQ) was 0.022 mg/kg. The standard substance of 1, 5, 10 mg/kg was added to the samples in the recovery test, the results showed that the recovery rate was in the range of 90.8%~95.8% and the relative standard deviation was 3.6%~9.0% (n=6). The method was simple, rapid and characterized with acceptable sensitivity and accuracy to meet the requirement of the detection of FOS in milk powder.