石墨探针收集,GPFAAS测定APM中痕量铝

一定规格的多孔石墨探针可在一特制的过滤装置中直接收集大气微粒物质(APM),通过石墨探针炉原子吸收光谱(GPFAAS)直接测定其中痕量铝的含量。采用基体改良剂Mg(NO_3)_2,含量低于2.5ng,吸光度(峰面积方式)低于0.25的铝,其分析校正曲线显示良好的线性且无记忆效应发生。采用本法测定标准参比材料(SRM 1604,城市微粒物质),铝的回收率为101％,相对标准偏差为3.8％,测定实验室大气微粒物质中铝的含量为749ng/m~3,相对标准偏差为8.1％。

DIRECT DETERMINATION OF TRACE ALUMINIUM IN ATMOSPHERIC PARTICULATE MATTER BY GRAPHITE PROBE FURNACE ATOMIC ABSORPTION SPECTROMETRY AFTER COLLECTION WITH A GRAPHITE PROBE FILTER

Direct determination of aluminium in atmospheric particulate matter (APM) was done using an integrated filtration and analysis system. The filtration and analysis system consisted of a porous electrographite plate which was used for the purpose of filtering APM and subsequently as a probe in graphite probe furnace atomic absorption spectrometry. The memory effect observed with higher amounts of aluminium were eliminated by reducing filtration times to below the amounts that produce memory effect. No memory effect was observed with less than 2. 5ng of aqueous standard of aluminium when magnesium nitrate was used as a chemical modifier for aluminium. The absorbance range (Peak-area mode) without memory effect was below 0. 25 A. s for aluminium. The analytical calibration curve for the aqueous standard of aluminium (Peak-area mode) showed excellent linearity in the range of absorbance. The result of analysis of the National Bureau of Standards (NBS), Standard Reference Material (SRM) No. 1648, Urban Particulate Matter , gave recovery of 101% and a precision of 3. 8% R. S. D. for aluminium. The result of analysis of APM in our laboratory atmosphere was Al 749ng/m3, precision 8. 1% R. S. D.