QuEChERS净化气相色谱法测定调味品中的防腐剂

The Determination on the Content of Preservatives in Flavoring by Qu ECh ERS Purification Gas Chromatography

试验旨在建立Qu ECh ERS净化气相色谱法检测调味品中对羟基苯甲酸酯类防腐剂含量,以确定其是否符合标准求。样品加入乙酸铵溶液酸化,经用乙酸乙酯提取,浓缩近干后用无水乙醇溶解通过QuEChERS净化,用气相色谱仪(FID)检测,外标法定量。在该方法试验条件下, 4种对羟基苯甲酸酯类在2~200 mg/kg范围内呈现良好线性关系,相关系数r2≥0.999,在样品中添加高、中、低3个水平浓度标液的加标回收率为97.6%~101.2%,试验方法相对标准偏差(SRSD, n=6)小于3%, 4种防腐剂的检出限为0.36~0.46 mg/kg。该方法在实际检验中操作简便,重现性好,且准确度、灵敏度高,适用于调味品等基质复杂的样品中对羟基苯甲酸酯类防腐剂的检测。

QuEChERS purification gas chromatography was established to detect the content of p-hydroxybenzoate preservatives in flavoring to determine whether it conforms to the standard.The samples were acidified with ammonium acetate solution,extracted with ethyl acetate,concentrated and nearly dried,then dissolved with anhydrous ethanol,purified with QuEChERS,detected by gas chromatograph(FID),and quantified by external standard method.Under the experiment condition of this method,the four kinds of p-hydroxy benzoic acid esters in 2 mg/kg and 200 mg/kg range showed a good linear relationship,with the correlation coefficient r2 acuity 0.999;The high,medium and low three concentration levels of the fluid added in the sample and the recovery was 97.6%-101.2%.The relative standard deviation(SRSD,n=6) of the experimental method was less than 3%.The detection limit of the four preservatives was 0.36-0.46 mg/kg.This method was easy to operate,reproducible,accurate and sensitive in practical test,and it was suitable for the detection of p-hydroxybenzoate preservatives in flavorings and other samples with complex substrates.