直接电导检测离子排斥色谱法测定酱油中的有机酸

Determination of Organic Acids in Soy 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酱油中多种有机酸。以Shim-packSCR-102H柱为分离柱,选用对甲苯磺酸和乙腈为淋洗液,考察了淋洗液浓度、色谱柱温度及淋洗液中乙腈含量对分离和测定有机酸的影响。通过实验确定最佳的色谱条件:2mmol/Lp-甲苯磺酸:乙腈(v/v,91/9)淋洗液,流速1.0mL/min,柱温50℃。方法对所测有机酸的检出限在0.06～1.05mg/L之间,相对标准偏差在3.3%以下(n=5),加标回收率在96.5%～100.6%之间。

Determination of organic acids in soy by Ion-exclusion chromatography with direct conductivity detection was developed. Chromatographic separation was performed on a Shim-pack SCR-102H column using p-toluenesulfonic acid containing acetonitrile as the eluent. The influences of p-toluenesulfonic acid concentration, column temperature and acetonitrile concentration on the separation of organic acids were investigated. The optimal separation of seven organic acids (citric, tartaric, malic, succinic, lactic, formic and acetic acid) was achieved at 50°C with the use of 91/9 (v/v) 2 mmol/L p-toluenesulfonic acid / acetonitrile as mobile phase. Detection limits for the organic acids ranged from 0.06 to 1.05 mg/L. RSDs of the peak area were lower than 3.3%. Recoveries of the organic acids after spiking were 96.5%￣100.6%.