浓度直读法快速测定酱菜中的氯离子

摘要

A new analytical method was presented, allowing the rapid and simple determination of chlorine ion in pickles through direct reading. Pickle samples were pretreated by means of ultrasonic. The determination was performed using a chloride ion- selective electrode. The relative standard deviations （RSD） for five replicate determinations of chlorine ion using a total ionic strength adjustment buffer （TISAB） at pH 5.50 containing 0.20 g/L trisodium citrate and 0.80 mol/L potassium nitrate were 1.9%~2.9%. The spike recovery rates of chlorine ion from four types of pickle samples were 94.1%- 105.6%. The limit of detection was 1.20 × 10^5 rnol/L. There was no significant difference between tiffs method and the national standard method as demonsWaled by F test and t test analysis. This method was economic, simple, fast and suitable for rapid on-site determination of chlorine ion.%建立一种简便快速测定食品中氯离子的新型分析方法,用超声波辅助技术处理酱菜样品,用氯离子选择性电极浓度直读法测定。结果表明：在总离子强度调节缓冲剂pH5.50、柠檬酸三钠添加量0.20g/L、硝酸钾浓度0.80mol/L时,样品测定的相对标准偏差为1.9%～2.9%（n=5）、加标回收率为94.1%～105.6%、氯离子的最低检出限为1.20×10-5mol/L,与国标法对照测定,F检验和t检验表明两种方法无显著性差异。该法成本低廉、简便快速,利于普及推广,用于样品的现场快速分析,结果满意。