直接进样离子色谱法测定食用碱中痕量无机阴离子

摘要

Trace inorganic anions in dietary alkali were directly injected and analyzed by Dionex ICS - 1000 ion-chromatograph and Dionex AS14 column with 3.5 mmol/L Na2CO3 - 1.0 mmol/L NaHCO3 as eluent.This method didn't need sample pretreatment and the existence of high concentrated sodium carbonate will not impact the determination of trace anions due to direct sample injection and conductivity detection.Detection limits for inorganic anions were all lower than 0.012 6 mg/L.Linear correlation coefficient was at 0.998 5 ～ 0.999 8.Relative standard deviation ( RSD ) was at 1.153％ ～3.218％ ( n =5 ).Standard sample recovery rate was at 93.77％ ～96.00％ which accorded with analysis and measurement requirements.%用Dionex ICS-1000离子色谱仪,Dionex AS14阴离子分离柱,以3.5 mmol/L碳酸钠-1.0 mmol/L碳酸氢钠为淋洗液,直接进样分析食用碱中的痕量无机阴离子.该法无需样品前处理,直接进样,电导检测,高浓度碳酸钠的存在不影响痕量阴离子的测定.所测的无机阴离子的检出限均在0.012 6 mg/L以下,线性相关系数为0.998 5～0.999 8,相对标准偏差为1.153%-3.218%(n=5),回收率为93.77%～96.00%,符合分析测定要求.