A reversed-phase high-performance liquid chromatographic (RP-HPLC) method was developed using poly(N-isopropylacrylamide)-grafted silica as stationary phase for the determination of preservatives benzoic acid and, methyl-, ethyl, propyl-, and n-butyl p-hydroxybenzoate in cosmetics. The separation was performed on a stainless steel column (250mm×4.6mm, 5μm). The methanol-phosphate buffer (55:45,pH=2.5) was used as mobile phase with a flow rate of 0.5mL/min and the detection was at 254nm. The sample was firstly pretreated on an aluminium oxide column. The eluent was analyzed by RP-HPLC. The calibration curves were linear in the ranges of 40～ 1000mg/L for benzoic acid, 4～ 100mg/L for methyl-,ethyl-and propyl-p-hydroxybenzoate, and 8～ 200μg/L for n-butyl p-hydroxybenzoate. The recoveries were 96.6％～106.9％, and RSDs were 0. 60％～1. 70％.%以聚N-异丙基丙烯酰胺硅胶键合相为固定相,建立了化妆品中苯甲酸、对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯和对羟基苯甲酸丁酯5种防腐剂的反相高效液相色谱测定方法.以不锈钢色谱柱(250mm×4.6mm,5μm)作为分离柱,以甲醇-磷酸盐缓冲液(55:45,pH=2.5)为流动相,流速0.5 mL/min,紫外检测波长254 nm.样品先通过氧化铝柱进行分离处理,馏出液用于色谱分析.校正曲线的线性范围分别为:40～1000mg/L(苯甲酸),4～100mg/L(对羟基苯甲酸甲酯,一乙酯,一丙酯),8～200mg/L(对羟基苯甲酸丁酯).回收率96.6%～106.9%,相对标准偏差0.60～1.70%.
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