【摘要】 建立了石墨炉原子吸收光谱法测定痕量银的方法。研究了仪器工作参数、分离条件及共存离子的干扰,确定了最佳测定条件。结果表明:地质样品经焙烧,用氢氟酸–盐酸–硝酸–高氯酸溶矿,在5%的盐酸介质中加入0.5m L 200 g/L的抗坏血酸溶液及0.25 m L 300 g/L的碘化钾溶液,并以2.0 m L 50 g/L的EDTA溶液掩蔽Cu2+,Pb2+,用2.0 m L甲基异丁基甲酮萃取分离银,在灰化温度500℃、原子化温度2 200℃条件下进行有机相测定。方法检出限为0.084μg/L,测定结果的相对标准偏差为1.89~3.91%(n=6),对国家一级标准物质测定,结果与标准值相符合。更多还原

【Abstract】 A graphite furnace atomic absorption spectrometry method for the determination of trace silver was developed based on MIBK extraction and separation in the medium of HCl–ascorbic acid–KI–EDTA. EDTA was used for shielding Cu2+, Pb2+. The working parameters of the instrument, separation condition and the interference of coexisting ions were investigated. Under the optimal conditions such as ashing temperature 500℃, atomization temperature 2 200℃, using MIBK extracting silver in the medium of HCl–ascorbic acid–KI–EDTA and organic phase detection, the detection limit was 0.084 μg/L and the relative standard deviation of determination results was 1.89%–3.91%(n=6). By using this method to detect the national standard samples, the results were consistent with standards values.更多还原