Bui L V, Cooper C
Department of Health, Division of Analytical Laboratories, Lidcombe, New South Wales, Australia.
J Assoc Off Anal Chem. 1987 Sep-Oct;70(5):892-6.
An isocratic liquid chromatographic (LC) technique is described for the determination of benzoic acid and sorbic acid in foods such as beverages, fruits, seafood, vegetables, sauces, and dairy, bakery, and confectionery products. A C18 column is used with methanol-phosphate buffer (5 + 95) as mobile phase and 4-hydroxyacetanilide or 3,5-dinitrobenzoic acid as internal standard. Sample preparation is simple, rapid, and produces a sample extract that has a minimum effect on the column performance and life. Specificity of the method was checked against common food additives such as L-ascorbic acid, caffeine, artificial sweeteners (saccharin, cyclamate, aspartame), antioxidants (BHT, BHA) and artificial colors. Also described are 2 procedures for confirmation of the preservatives, using either redox reaction of sorbic acid with potassium permanganate or gas chromatography/mass spectrometry. Mean recoveries of 90-105% were obtained with a precision of 1-6% and a detection limit of 20 mg/kg for the 2 preservatives.
本文描述了一种等度液相色谱（LC）技术，用于测定饮料、水果、海鲜、蔬菜、酱汁以及乳制品、烘焙食品和糖果等食品中的苯甲酸和山梨酸。使用C18柱，以甲醇 - 磷酸盐缓冲液（5 + 95）作为流动相，并以4 - 羟基乙酰苯胺或3,5 - 二硝基苯甲酸作为内标。样品制备简单、快速，且所得到的样品提取物对色谱柱性能和寿命的影响最小。该方法的特异性针对常见食品添加剂进行了验证，如L - 抗坏血酸、咖啡因、人工甜味剂（糖精、甜蜜素、阿斯巴甜）、抗氧化剂（丁基羟基甲苯、丁基羟基茴香醚）和人工色素。还介绍了两种用于确认防腐剂的方法，一种是利用山梨酸与高锰酸钾的氧化还原反应，另一种是气相色谱/质谱法。两种防腐剂的平均回收率为90 - 105%，精密度为1 - 6%，检测限为20 mg/kg。
