地质样品中微量金银的在线分离富集方法

DETERMINATION OF TRACE GOLD-SILVER IN GEOLOGICAL SAMPLES BY FLOW INJECTION ON-LINE SEPARATION AND PRECONCENTRATION- FLAME ATOMIC ABSORPTION SPECTROMETRY

提出用ＶＳ－Ⅱ型强碱性阴离子交换纤维定量富集、硫脲解脱，流动注射在线分离富集—火焰原子吸收光谱法测定地质样品中痕量金银的分析方法。该方法检出限低，金为１．４μｇ／ｍＬ，银为０．３５μｇ／ｍＬ，相对标准偏差均小于２％，采样频率为１２０次／ｈ，用于地质样品中痕量金银的直接测定，结果令人满意。

The comtination technique of the flow injection on-line separation and preconcentration with VS-Ⅱ type anion exchange filter-flame atomic absorption spectrometry was used to determine the trace elements gold and silver in geological samples. The analysing solution with acidity 3% (HCl and HNO 3) passed through the column at a flow rate of 4.8 mL/min, the enrichment time was 20 s, gold and silver on the column can easily be eluted with thiouea at a flow rate of 2.0 mL/min, and introduced into the nebulizer burner system of FAAS. The detection limit is 1.4 ng/mL for gold and 0.35 ng/mL for silver; the relative standard deviations (n=6.20 ng/mL, Au, Ag) are less 2.0%, Abouct 120 samples can be analysed in an hour. The method has been applied to determine trace Au and Ag in geologcal samples with satisfactory results.