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将大气飘尘样品收集到0.8微米微孔滤膜内,用HNO_3-H_2SO_4混酸将样品消化。在负压发生器内用1%NaBH_4将样品中的砷和硒还原为氢化物。使用真空泵将氢化物直接吸入到电热、真空石英管原子化器中,同时用原子吸收仪器测量样品信号的峰值吸光度。本法测量砷和硒的检出限分别为0.61和0.06纳克。
The air-borne dust samples were collected into 0.8 micron microporous membrane, HNO_3-H_2SO_4 mixed acid samples were digested. Arsenic and selenium in the sample were reduced to hydride with 1% NaBH 4 in a negative pressure generator. Hydride was aspirated directly into an electrothermal, vacuum quartz tube atomizer using a vacuum pump, while the peak absorbance of the sample signal was measured with an atomic absorption spectrometer. The detection limit of arsenic and selenium in this method are 0.61 and 0.06 ng respectively.