离子色谱法测定工作场所空气中六价铬含量

IC Determination of Hexavalent Chromium in Air of Working Place

摘要: 采用离子色谱法测定工作场所空气中六价铬的含量。采用碱性微孔滤膜采集工作场所空气样品，经4.0 mmol·L^-1碳酸钠溶液超声洗脱后，选用Metrosep A Supp 4-250型阴离子色谱柱（250 mm×4.0 mm）进行色谱分离。以4.0 mmol·L^-1碳酸钠-1.0 mmol·L^-1碳酸氢钠混合液为流动相，抑制型电导检测器测定。六价铬的质量浓度在0.01~10.0 mg·L^-1内与其峰面积呈线性关系，方法的检出限（3S/N）为4×10^-3mg·L^-1。加标回收率在95.2%~97.6%之间，测定值的相对标准偏差（n=6）在2.2%~3.8%之间。

Abstract: IC was applied to the determination of hexavalent chromium in air of working place. Air sample of working place was collected by alkline microporous membrane filter, and the Cr(Ⅵ) on the filter was eluted ultrasonically with 4.0 mmol·L^-1 Na₂CO₃ solution. Metrosep A Supp 4-250 anionic column (250 mm×4.0 mm) was used for chromatographic separation. Mixture of 4.0 mmol·L^-1 Na₂CO₃ and 1.0 mmol·L^-1 NaHCO₃ solution was used as mobile phase, and restraining conductance detector was used in determination. Linear relationship between values of peak area and mass concentration of hexavalent chromium was kept in the range of 0.01-10.0 mg·L^-1, with detection limit (3S/N) of the method of 4×10^-3mg·L^-1. Values of recovery found by standard addition method were in the range of 95.2%-97.6%, and values of RSD's (n=6) in the range of 2.2%-3.8%.