离子色谱法同时测定微晶纤维素中氯离子和硫酸根离子含量

Simultaneous Determination of Chloride Ion and Sulfate Ion in Microcrystalline Cellulose by Ion Chromatography

目的建立同时测定微晶纤维素中氯离子和硫酸根离子含量的离子色谱法。方法色谱柱为Dionex IonPac AS19柱(250 mm×4 mm,5μm),保护柱为IonPac AG19 Guard柱(50 mm×4 mm,5μm);检测器为电导检测器,检测器温度为30℃,检测方式为抑制电导检测;以氢氧化钾为淋洗液进行分析柱梯度洗脱,流速为1.0 mL/min;柱温为30℃;进样量为25μL。结果氯离子、硫酸根离子质量浓度分别在0.02~1.5μg/mL(r=0.9998,n=6)和0.1~1.5μg/mL(r=0.9991,n=6)范围内与峰面积线性关系良好;精密度、稳定性、重复性试验的RSD均小于2.20%;平均加样回收率分别为97.71%和97.63%,RSD分别为2.24%和3.75%(n=9)。15批样品的氯离子和硫酸根离子含量分别在0.0026%~0.0068%和0.0033%~0.0110%之间。结论所建立的方法简单准确、灵敏度高,可用于微晶纤维素中氯离子和硫酸根离子的含量控制。

Objective To establish an ion chromatography method for simultaneous determination of chloride ion and sulfate ion in microcrystalline cellulose.Methods The chromatographic column was Dionex IonPac AS19 column(250 mm×4 mm,5μm),and the protective column was IonPac AG19 Guard column(50 mm×4 mm,5μm),the detector was a conductivity detector,and the detector temperature was 30℃.The detection method was suppression conductivity detection.The gradient elution of analytical column was carried out with potassium hydroxide as gradient eluent,and the flow rate was 1.0 mL/min,the column temperature was 30℃,the injection volume was 25μL.Results The mass concentrations of chloride ion and sulfate ion were in the ranges of 0.02-1.5μg/mL(r=0.9998,n=6)and 0.1-1.5μg/mL(r=0.9991,n=6),which showed a good relationship with the peak area.The RSDs of precision,stability and repeatability tests were less than 2.20%.The average recoveries of chloride ion and sulfate ion were 97.71%and 97.63%with RSDs of 2.24%and 3.75%(n=9),respectively.The contents of chloride ion and sulfate ion in 15 batches of samples were in the ranges of 0.0026%-0.0068%and 0.0033%-0.0110%,respectively.Conclusion The method is simple,accurate and sensitive,which can be used to control the content of chloride ion and sulfate ion in microcrystalline cellulose.