离子色谱法测定汽车尾气净化催化剂中Cl-和NO3-的含量

离子色谱法测定汽车尾气净化催化剂中Cl^-和NO₃^-的含量

摘要: 汽车尾气净化催化剂样品（0.5 g），用3%（体积分数）氨水溶液（30 mL）超声提取。所得提取液中的Cl^-和NO₃^-用IonPac AS11-HC （4 mm×250 mm）作为分离柱，以17 mmol·L^-1氢氧化钾溶液为淋洗液进行色谱分离，用抑制型电导检测器测定。Cl^-和NO₃^-的质量浓度均在0.1~10.0 mg·L^-1内与其对应的峰高呈线性关系，Cl^-和NO₃^-的检出限依次为0.004，0.019 mg·L^-1。方法用于实际样品分析，并进行加标回收试验，测得回收率在98.8%~116%之间，测定值的相对标准偏差（n=7）不大于2.0%。

Abstract: The sample of automobile tail gas purification catalyst (0.5 g) was ultrasonically extracted with ammonia 3% (φ) solution (30 mL). Cl^- and NO₃^- ion in the extract were separated by IC, using IonPac AS11-HC (4 mm×250 mm) column as separation column and 17 mmol·L^-1 KOH solution as eluant. Restrain conductance detector was used in the determination. Linear relationships between values of peak height and mass concentration of Cl^- and NO₃^- were kept in the same range of 0.1-10.0 mg·L^-1, with detection limits of Cl^- and NO₃^- of 0.004, 0.019 mg·L^-1 respectively. The proposed method was applied to the analysis of substantial samples and recovery was tested by standard addition method, giving values of recovery in the range of 98.8%-116% and RSD's (n=7) no more than 2.0%.