碱消解-石墨炉原子吸收光谱法测定PM10中的六价铬

摘要

Being dispelled in 95℃ water by the addition of magnesium chloride and buffer medium of K2HPO4–KH2PO4 in alkaline medium. The concentration of Cr(Ⅵ) in PM10 of TEOMfilm was determined by graphite furnace absorption spectrometry. The concentration of Cr(Ⅵ) had good linearity with the asorbance in the range of 0.0–2.0μg/L with the correlation coefficient of 0.999 7. The detection limit was 2.10×10–6μg/m3 for Cr(Ⅵ) analysis in 1 000 m3 ambient air. The recovery was 89.0%–94.3%, and the relative standard deviation of determination results was 2.2%(n=7). The method meets the requirement of limit value of 2.5×10–5μg/m3 in the ambient air quality standards.%在碱性介质中，加入氯化镁和磷酸氢二钾–磷酸二氢钾缓冲溶液，95℃水浴消解溶出样品中的Cr(Ⅵ)，采用石墨炉原子吸收光谱法测定TEOM膜中PM10的Cr(Ⅵ)含量。Cr(Ⅵ)质量浓度在0.0～2.0μg／L范围内与吸光度线性良好，相关系数为0.9997。当采集1000 m3环境空气时，方法检出限为2.10×10–6μg／m3。实际样品加标回收率为89.0%～94.3%，测定结果的相对标准偏差为2.2%（n=7）。该法满足环境空气质量标准中规定的Cr(Ⅵ)年平均浓度2.5×10–5μg／m3限值的要求。