离子色谱法测定饮料中6种可溶性阴离子

Determination of 6 soluble anions in beverages by ion chromatography

建立离子色谱法测定饮料中6种可溶性阴离子。采用膜分离、抽滤离心、固相萃取柱、惰性气体吹扫方式进行样品处理。以2.4 mmol/L Na_(2)CO_(3)-1 mmol/L NaHCO_(3)溶液为淋洗液,经SHY-A-6色谱柱(250 mm×4.0 mm)分离,流量为1.0 mL/min,进样体积为50μL。氟离子、溴离子、亚硝酸根离子的质量浓度在0.00~2.00 mg/L范围内,硝酸根离子的质量浓度在0.00~20.0 mg/L范围内,氯离子、硫酸根离子的质量浓度在0.00~40.0 mg/L范围内与色谱峰高具有良好的线性关系,相关系数均不小于0.9995,方法检出限为0.0008~0.0038 mg/L。样品加标回收率为100.6%~103.2%,平行测定结果的相对标准偏差为0.22%~0.87%(n=6)。该方法快速、稳定、选择性好,适用于检测饮料中可溶性阴离子。

An ion chromatographic method was established for the determination of six soluble anions in beverages.The beverages were processed by membrane separation,extraction and centrifugation,solid phase extraction column and inert gas purge.The separation was performed on a SHY-A-6 column(250 mm×4.0 mm)with a eluent flow rate of 1.0 mL/min and an injection volume of 50μL using 2.4 mmol/L Na_(2)CO_(3)-1 mmol/L NaHCO_(3) solution as the eluent.The mass concentrations of fluoride ion,bromide ion and nitrite ion in the range of 0.00-2.00 mg/L,the mass concentrations of nitrate ion in the range of 0.00-20.0 mg/L,the mass concentrations of chloride ion and sulfate ion in the range of 0.00-40.0 mg/L had a good linear relationship with the chromatographic peak height,the correlation coefficients were not less than 0.9995,and the limits of detection were 0.0008-0.0038 mg/L.The recoveries were 100.6%-103.2%,and the relative standard deviations of the parallel determination results were 0.22%-0.87%(n=6).The method is rapid,stable,selective and suitable for the determination of soluble anions in beverages.