离子色谱法测定减水剂中的阴离子

建立一种离子色谱法同时测定减水剂中的葡萄糖酸根、氯离子、硫酸根、硫代硫酸根.样品经过稀释、C18小柱预处理后直接进样.选用shodex52-4e阴离子交换柱分离样品,淋洗液为3.6mmol·L^-1Na₂CO₃,柱温50℃,流速0.8mL·min^-1,进样量7μL,抑制电导检测,外标法定量,当葡萄糖酸根、氯离子、硫酸根、硫代硫酸根的质量分数分别为5.0~100.0,0.1~30.0,1.0~50.0,1.0~50.0mg·L^-1时,与色谱峰面积呈良好的线性关系(r≥0.9991),相对标准偏差(n=7)均小于2.5%,检出限在50.23~13.44μg·L^-1.将该方法应用于减水剂阴离子的测定,加标回收率在80.6%~113.9%,方法选择性高、灵敏度好且操作简便.

Determination of anions in the water reducing agent by ion chromatograph

A novel method is presented for the simultaneous determination of gluconate, chloride, sulfate and thiosulfate in the water reducing agent using ion chromatography with suppressed conductivity detector was eastablished. The sample is diluted with water and filtered through C18 pretreatment column before injection. The separation is performed on shodex 52-4e anion exchange column with 3.6 mmol·L^-1 Na₂CO₃ at flow rate of 0.8 mL· min^-1. The sample injection volume is 7 μL. Under the optimum conditions, it shows the good linear relationships (r≥0.999 1) between the mass concentration and the peak areas when the concentrations of gluconate, chloride, sulfate and thiosulfate were in the range of 5.0 to 100.0,0.1 to 30.0,1.0 to 50.0,1.0 to 50.0 mg· L^-1, respectively. The recovery rate ranged from 80.6% to 113.9% with the relative standard deviations (RSDs) within 2.5% (n=7).What's more, detection limits calculated at S/N=3 are within 50.23 and 13.44 μg· L^-1. The method has been applied to detect the anions in the water reducing agent, which shows high selectivity, sensitivity and accuracy, meanwhile easy to implement.