离子色谱法测定聚合物材料中铬(Ⅵ)含量

IC Determination of Chromium(Ⅵ) in Polymers

采用离子色谱法测定聚合物材料中的铬(Ⅵ)含量。取粒径小于250μm的聚合物样品用0.5mol·L-1氢氧化钠溶液提取3h。分取适量提取液经过滤及RP柱净化后,通过IonPac AG19保护柱及DIONEX IonPac AS19阴离子分离柱分离,先后用25mmol·L-1和50mmol·L-1的氢氧化钠溶液淋洗分离柱,采用抑制电导检测器检测。铬(Ⅵ)的质量浓度在0.10~10.0mg·L-1范围内与其峰面积呈线性关系,检出限(3s/k)为7mg·kg-1。对聚氯乙烯(PVC)样品连续测定8次,测定值的相对标准偏差为9.2%。用标准加入法进行方法的回收试验,测得回收率在95.2%~105%之间。

Content of Cr(Ⅵ)in polymer materials was determined by IC.The polymer sample with granular size<250μm was extracted for 3hwith 0.5mol·L-1 NaOH solution.An appropriate aliquot of the extract was purified by filtration and passing through the RP column.IonPac AG19 protective column and DIONEX IonPac AS19 anion separation column were used for separation and 25mmol·L-1 and 50mmol·L-1 NaOH solutions were used for elution.Inhibitorty conductivity detection was adopted in the determination.Linear relationship between values of peak area and mass concentration of Cr(Ⅵ)was kept in the range of 0.10-10.0mg·L-1 with detection limit(3s/k)of 7mg·kg-1.Precision of the method was tested with the PVC sample for 8determination,value of RSD found was 9.2%.Test for recovery was performed by standard addition method,giving recovery in the range of 95.2%-105%.