微波消解-火焰原子吸收光谱法测定铅烟灰和铅泥中银

Determination of silver in lead ash and lead mud by atomic absorption spectrometry after microwave digestion

采用王水和氟化铵在微波消解仪中消解样品,建立了火焰原子吸收光谱法测定铅烟灰和铅泥中银的方法。考察了溶样方法、消解试剂、微波消解程序、盐酸浓度和干扰离子对测定的影响。结果表明,以王水和氟化铵为消解试剂,采用三步消解程序即60℃、8atm/1min,70℃、13atm/2min,100℃、20atm/3min,效果最佳;铅泥和铅烟灰中的铜对银的测定没有影响;银浓度在0.2～10μg/mL范围内与吸光度呈线性关系,方法检出限为0.03μg/mL。采用本方法对铅烟灰和铅泥样品中的银进行分析,测得结果与常规溶样-原子吸收光谱法基本吻合,相对标准偏差(RSD,n=5)为1.1%～1.3%。

A novel method for the determination of silver in lead ash and lead mud was established by flame atomic absorption spectrometry after microwave digestion with aqua regia and ammonium fluor ide. Such experiment conditions were investigated as the influence of sample dissolution methods, di gestion reagents, microwave digestion program, hydrochloric acid concentration and interfering ions on the determination. The results indicated that the digestion effect was optimum with threestep di gestion program including 60 ℃ and 8 atm/l rain, 70℃ and 13 atm/2 min, 100 ℃ and 20 atm/3 min and aqua regia and ammonium fluoride as digestion reagents. Copper in lead ash and lead mud has no effect on the determination of silver. Experiment indicated that silver concentration within the range of 0. 210 /lg/mL had linear relationship with its absorbance. Detection limit of this method was 0.03 μg/mL. The proposed method was applied to the determination of lead ash and lead mud samples. The results were consistent with those obtained by conventional sample dissolutionatomic absorption spectrometry, and the relative standard deviations （RSDs, n=5） were 1.1%-1.3%.