离子色谱与恒电位法检测饮料中有机酸含量

Detection on the Content of Organic Acid in Beverages by Ion Chromatography-Constant Potential

采用离子色谱与恒电位法联用方法对苹果汁中有机酸进行检测。采用硝酸为流动相,以IonPac AS11-HC阴离子交换柱分离后以恒电位仪为检测器进行安培检测,进样量为25μL时有机酸离子的检出限(以3倍信噪比计)可降至0.2μg/L,痕量有机酸离子标准溶液平行9次进样测定的相对标准偏差为2.3%,经过几百组测试,稳定性好、线性、重现性及灵敏度均令人满意。

The organic acid determination using ion chromatography has been researched.With the CHI660 Electrochemical Detector,the Detection Limit of the method （S/N ratio of 3）has reached 0.2 μg/L （25 μL injected）,using HNO3 as the mobile phase and the AS11-HC as the separate column.The Relative Standard Deviation（RSD）was 2.3 %（n=9）.A method of constant potential has been established.And compared with the conductivity detector method and the method of nitrate acid mobile phase,the constant potential Determination method is better than them.