碱消解-电感耦合等离子体发射光谱法测定聚氯乙烯中的六价铬

Determination of Hexavalent Chromium in Polyvinyl Chloride by Alkali DigestionInductively Coupled Plasma Optical Emission Spectrometry

聚氯乙烯(PVC)样品加入50mL碱性消解液(30g/L碳酸氢钠-20g/L氢氧化钠),加入0.2g氯化镁和0.5mL磷酸氢二钾-磷酸二氢钾缓冲溶液。在水浴温度为90~95℃,旋转转速为140r/min,消解时间为60min的条件下消解。采用电感耦合等离子体发射光谱仪(ICPOES)对提取液中的六价铬含量进行测定。结果表明,测试方法具有良好的线性关系,仪器拟合线性回归方程为:I=22750C+1071.7,相关系数为0.9997;方法检出限为1.03mg/kg,定量限为5.15mg/kg,加标回收率在89.4%~92.4%,相对标准偏差在2.3%~8.5%。本方法简单,易操作,稳定性好,结果准确可靠。

Add 50 mL alkaline digestion solution(30 g/L sodium bicarbonate-20 g/L sodium hydroxide), 0.2 g magnesium chloride and 0.5 mL dipotassium hydrogen phosphate-potassium dihydrogen phosphate buffer solution to polyvinyl chloride(PVC) sample.Decompose under the conditions of water bath temperature of 90 ~ 95℃, rotating speed of 140 rpm and digestion time of 60 minutes. Inductively coupled plasma emission spectrometer(ICP-OES) was used to determine the hexavalent chromium content in the extract. The results show that the test method has a good linear relationship, and the linear regression equation fitted by the instrument is: I=22750C+1071.7, and the correlation coefficient is 0.9997;The detection limit of the method is 1.03 mg/kg, the quantitative limit is 5.15 mg/kg, the recovery rate is 89.4% ~ 92.4%, and the relative standard deviation is 2.3% ~8.5%. This method is simple, easy to operate, stable and accurate.