流动注射在线离子交换分离富集原子吸收测定地质物料中痕量银

Determination of Trace silver in Geol ogical Material s by Flow Injection Flame Atomic Absorption Spectrometrywith On-line Ion-exchange Separation and Preconcentration

采用流动注射在线离子交换分离富集技术使［ＡｇＣｌ＿２］￣－通过装填有４１０哌啶树脂的微型柱而被吸附，随后用硫脲梯度洗脱，再用原子吸收法进行测定。每次消耗样品溶液６．６ｍｌ，进样频率为２８次／ｈ时浓集倍率２２。方法检出限０．３μｇ／Ｌ（３σ），对于含Ａｇ３０μｇ／Ｌ试样进行１２次测定，其平均值为２９．０μｇ／Ｌ精度（ＲＳＤ）为２．９％，方法经地质标样分析验证可靠。

he silver is first converted into its[ AgCl_]￣- complex to allow its absorption on a micro-column packed with piperidine resin 4 1 0.The Ag is eluted with thiourea and determined by AAS. The method consumes 6. 6ml sample solution in every determination,with an enrichmentfactor of 22. The detection limit is 0.3μg/L(3σ)at a sampling frequency of 28 samples per hour.The precision is 2.9%RSD(n=12)at the 30μg/L level.The method has been applied to the determination of trace silver in geological samples with satisfactory results.