气相色谱法测定油豆腐中山梨酸、苯甲酸

目的建立油豆腐中山梨酸和苯甲酸的毛细管柱气相色谱检测方法。方法在碱性条件下,样品利用硫酸锌去除基体干扰,水溶液提取,提取液经酸化后乙醚提取,浓缩后乙醇定容,用气相色谱进行分离测定。结果浓度在50～300μg/ml时,各组分线性良好(苯甲酸r=0.999 6,山梨酸r=0.999 4)。方法的相对标准偏差为1.07%～3.14%,回收率为90.6%～101.8%。结论该方法简便、快速、准确、稳定,适用于油豆腐中山梨酸和苯甲酸的检测。

Determination of sorbic,benzoic acid in oily bean curd by gas chromatography

Objective To develop a method to detect benzoic,sorbic acid in oily bean curd by capillary gas chromatography.Methods In alkaline condition,the samples were eliminated matrix interference by ZnSO4,extracted aqueous solution,then acidized,extracted by ether,fixed using anhydrous ethanol and finally determined by capillary gas chromatography.Results The linear range was 50-300 μg/ml(benzoic acid r=0.999 6,sorbic acid r=0.999 4).The relative standard deviation was 1.07%-3.14%,The recovery was 90.6%-101.8%.Conclusion This method is simple,rapid accurate and reliable to detect the benzoic,sorbic acid of oily bean curd.