Küppers F J, Jans J A
State Food Inspection Service, Leeuwarden, The Netherlands.
J Assoc Off Anal Chem. 1988 Sep-Oct;71(5):1068-71.
The sorbate and benzoate contents of commercial fresh cheese (quarg) samples are determined by reverse-phase liquid chromatography following extraction with a methanol-acetate buffer pH 4.5 mixture (37 + 63). The mobile phase is acetonitrile-acetate buffer pH 4.5 (20 + 80), the effluent flow rate is maintained at 1.0 mL/min, and the detector is set at 232 nm. Recoveries from quarg spiked at the 5-50 mg/kg level ranged from 95 to 99%, which compares favorably with methods previously published. Precision averaged 2-5% RSD, whereas the limit of detection was 0.3 mg/kg (sorbic acid) and 1.0 mg/kg (benzoic acid).
采用甲醇 - 乙酸缓冲液（pH 4.5）混合液（37 + 63）萃取后，通过反相液相色谱法测定市售新鲜奶酪（夸克奶酪）样品中的山梨酸盐和苯甲酸盐含量。流动相为乙腈 - 乙酸缓冲液（pH 4.5）（20 + 80），流出液流速保持在1.0 mL/min，检测器设定在232 nm。在5 - 50 mg/kg水平加标的夸克奶酪回收率在95%至99%之间，与先前发表的方法相比具有优势。精密度平均为2 - 5%相对标准偏差，而检测限为0.3 mg/kg（山梨酸）和1.0 mg/kg（苯甲酸）。
