苯基荧光酮沉淀捕集-GFAAS测定痕量镓、锗、钼和铟

以苯基荧光酮沉淀捕集溶液中的痕量镓、锗、钼和铟，用石墨炉原子吸收法进行测定。研究了溶液酸度、苯基荧光酮(PF)用量、陈化时间、溶液体积以及共存元素的影响。最佳条件分别为：Ga(Ⅲ)：500 mL pH≈2溶液中加入10.00 mg·mL-1 PF 2.00 mL，陈化4h;Ge(Ⅳ)：500 mL pH≈2溶液中加入10.00 mg·mL-1 PF 4.00 mL，陈化10 h;Mo(Ⅴ)：1 000 mL pH≈3溶液中加入10.00 mg·mL-1 PF 3.00 mL，陈化6 h;In(Ⅲ)：100 mL pH≈5溶液中加入10.00 mg·mL-1 PF 4.00 mL，陈化10 h。实验显示，苯基荧光酮沉淀对痕量镓、锗、钼和铟的捕集过程以后沉淀为主。方法检出限(3s)：镓0.12 ng·mL-1, 锗0.30 ng·mL-1, 钼0.046 ng·mL-1,铟2.7 ng·mL-1。该方法成功地用于石墨炉原子吸收测定水溶液、国家地质标准物质和锌精矿中痕量镓、锗、钼和铟。

Precipitation Trapping with Phenylfluorone and Determination of Trace Gallium, Germanium, Molybdenum and Indium by GFAAS

The preconcentration of trace gallium, germanium, molybdenum and indium by trapping with precipitation of phenylfluorone (PF), and the determination of the elements by GFAAS were developed. The effects such as those of acidity, amounts of PF, aging time, volume of test solution, and the coexistent ions on the preconcentration of the trace elements were examined in detail. The optimum conditions of preconcentration for Ga(III) were pH approximately 2 test solution 500 mL with added 10.00 mg x mL(-1) PF (2.00 mL) and aging for 4 h, those for Ge(IV) were pH approximately 2 test solution 500 mL with added 10.00 mg x mL(-1) PF (4.00 mL) and aging for 10 h, those for Mo(V) were pH approximately 3 test solution 1 000 mL with added 10.00 mg x mL(-1) PF (3.00 mL) and aging for 6 h, and those for In(III) were pH approximately 5 test solution 100 mL with added 10.00 mg x mL(-1) PF (3.00 mL) and aging for 10 h. The experiment results showed that the main contribution to trapping trace gallium, germanium, molybdenum and indium with PF precipitation was post-precipitation instead of coprecipitation. The detection limits (3s) were 0.12 ng x mL(-1) for gallium, 0.30 ng x mL(-1) for germanium, 0.046 ng x mL(-1) for molybdenum and 2.7 ng x mL(-1) for indium. The developed methods were successfully applied to the determination of trace amount of the elements in water samples, geological standard reference materials, and zinc concentrate samples by graphite furnace atomic absorption spectrometry.