直接电导检测-离子排斥色谱法测定芳香族羧酸

Determination of Aromatic Carboxylic Acids by Ion-exclusion Chromatography with Direct Conductivity Detection

研究了直接电导检测-离子排斥色谱法分离测定芳香族羧酸(邻苯二甲酸、水杨酸、苯乙酸、对羟基苯甲酸、苯甲酸和邻甲苯甲酸)。以Shim-packSCR-102H色谱柱为分离柱,H2SO4为流动相,考察了流动相浓度、色谱柱温度、流速对分离和测定芳香族羧酸的影响,确定最佳色谱条件为:0.08mmol/LH2SO4作为流动相,柱温45℃,流速1.2mL/min。所测芳香族羧酸的检出限为0.07～0.98mg/L;相对标准偏差在2.6%以下(n=5);回收率为95.8%～100.1%。本方法用于酱油样品的分析,得到满意结果。

Ion-exclusion chromatography with direct conductivity detection was employed for the separation and determination of six aromatic carboxylic acids （o-phthalic acid, salicylic acid, phenyl acetic acid, p-hydroxy benzoic acid, benzoic acid, o-toluic acid）. Chromatographic separation was performed on a Shim-pack SCR-102H column （8.0 mmi. d.×300mm） with sulfuric acid as the eluent. The influence of the eluent concentration, the column temperature and flow rate of eluent on the retention of aromatic carboxylic acids was investigated. Excellent conditions for the simultaneous separation and determination of six aromatic carboxylic acids were achieved at 45℃ with the use of 0.08 mmol/L sulfuric acid as eluent. The detection limits （S/N = 3 ） of six aromatic carboxylic acids were obtained in the range of 0.07 - 0.98 mg/L. The relative standard deviations of the chromatographic peak areas for six aromatic carboxylic acids were less than 2.6% （n=5） and the recoveries of spiked components were 95.8% to 100.1%. The method has been applied to the determination of aromatic carboxylic acids in the sauce with satisfactory results.