顶空气相色谱-质谱联用法测定食品中的亚硫酸盐含量

Determination of Sulfite in Food by Headspace Gas Chromatography-Mass Spectrometry

目的:建立顶空气相色谱-质谱联用法测定食品中亚硫酸盐含量的方法。方法:样品在顶空瓶内与磷酸介质发生反应使得产物二氧化硫(Sulfur dioxide,SO_(2))溢出,在恒温下达到气液两相平衡状态。采用GS-GASPRO气相色谱柱分离,经电子轰击离子源(Electron impact ion source,EI)电离后以总离子流(Total ion current,TIC)模式进行数据采集与分析,依据保留时间及质谱信息定性,标准曲线法定量。结果:该方法在5.0~5000.0μg/mL质量浓度范围内呈良好线性,相关系数r^(2)=0.999,检出限(limits of detection,LODs)为0.336 mg/kg,定量限(Limits of quantitation,LOQs)为1.120 mg/kg。测得竹笋、酸菜等五种样品的加标回收率在91.3%~108.8%,相对标准偏差(Relative standard deviations,RSDs)小于6%(n=6)。应用方法对多种样品进行检测,其中蔬菜罐头类以及腌渍食品检测结果多为亚硫酸盐超标。结论:该方法前处理简单、检测时间短、精密度高,适合大批量的食品中添加剂亚硫酸盐的检测。

Objective:To establish a method for the determination of sulfite in food by headspace gas chromatography-mass spectrometry(HS-GC-MS).Methods:Sulfur dioxide(SO_(2)) was produced by the reaction of the sample with phosphoric acid in the headspace bottle,and reached the equilibrium state of gas-liquid phase at constant temperature.GS-GASPRO gas chromatography column was used for separation,after electron impact ion source(EI)ionization,the data were collected and analyzed by total ion current(TIC)mode.Results:The correlation coefficient of the standard working curve of this method is 0.999,the detection limit(LODs)is 0.336 mg/kg,and the quantification limit(LOQs)is 1.12 mg/kg.The recovery rates of the five samples including bamboo shoots and sauerkraut were 91.3%~108.8%,and the relative standard deviations(RSDs)was less than 6%(n=6).The method was applied to samples,of which the test results of canned vegetables and pickled food were mostly sulfite.Conclusion:The method has the advantages of simple pretreatment,short detection time and high precision and is suitable for the determination of sulfite in large quantities of food.