离子色谱法测定聚苯乙烯磺酸钙散剂中的钠、钙含量及钾交换量

Determination of sodium,calcium and potassium exchange capacity in calcium polystyrene sulfonate by ion chromatography

目的:建立离子色谱法测定聚苯乙烯磺酸钙散剂中的钠离子和钙离子的含量,以及钾交换量。方法:采用Dionex IonpacCS12A阳离子柱(250 mm×4 mm),以不同浓度甲烷磺酸溶液为流动相进行梯度洗脱,流速为1.0 mL·min^(-1),采用抑制型电导检测器检测。结果:钠离子、钾离子和钙离子分别在0.2~10、10~100和16~24μg·mL^(-1)内线性关系良好,相关系数(r)均大于0.9998,检测限分别为0.01440、0.06098和0.06000 ng·mL^(-1),定量限分别为0.04799、0.2026和0.2000 ng·mL^(-1);回收率分别为90.4%~105.3%(RSD为1.6%~5.5%),98.2%~102.3%(RSD为0.5%~0.9%)和97.6%~102.9%(RSD为1.3%~2.7%);重复性RSD分别为4.7%、1.3%和1.7%。3批样品中钠离子测定结果分别为0.506%、0.462%和0.435%;钾交换量分别为0.0628、0.0605和0.0600 g·g^(-1);钙离子含量分别为8.35%、8.35%和8.34%。结论:该方法准确可靠,简便高效,适用于聚苯乙烯磺酸钙散剂中钠离子和钙离子的含量以及钾交换量的同时测定。

Objective:To establisha method with ion chromatographyfor simultaneous determin^(-1)ation of sodium,calcium and potassium exchange capacity in calcium polystyrene sulfonate.Methods:The separation was performed on aDionexIonpacCS12 A(250 mm×4 mm)column with methanesulfonic acid solution as mobile phase for gradient elution and detected with suppressedconductance detector.The rated was 1.0 mL·min^(-1).Results:The IC method established showed linear calibration in the ranges of 0.2-10,10-100 and 16-24μg·mL^(-1)for sodium,potassium and calcium with r≥0.9998,respectively.The lower limits of detectionwere 0.01440,0.06098 and 0.06000 ng·mL^(-1),the lower limits of qualification were 0.04799,0.2026 and 0.2000 ng·mL^(-1).The recoveries of sodium,potassiumand calcium were 90.4%-105.3%(RSD were 1.6%-5.5%),98.2%-102.3%(RSD were 0.5%-0.9%)and 97.6%-102.9%(RSD were 1.3%-2.7%),respectively.The intra-day precision of sodium,potassiumand calciumwere 4.7%,1.3%and 1.7%,respectively.The contents of sodium in three differentcalcium polystyrene sulfonates were 0.506%,0.462%and 0.435%.The potassium exchange capacitieswere 0.0628,0.0605 and 0.0600 g·g^(-1).The contents ofcalcium were 8.35%,8.35%and 8.34%.Conclusion:The established ion chromatographymethod was accurate and suitable for the determin^(-1)ation of sodium,calcium and potassium exchange capacity in calcium polystyrene sulfonate.