勘查地球化学找矿中重要指示元素的野外快速分析法（二）银的分析方法

RAPID FIELD ANALYTICAL METHODS FOR IMPORTANT INDICATOR ELEMENTS IN GEOCHEMICAL EXPLORATION: (Ⅱ) ANALYTICAL METHOD OF SILVER

发展了一种可在野外快速测定０．０１０—５０μｇ／ｇ银量的新方法。此法由两个各自独立而又配套的部分组成。一是直接测定０．２５—５０μｇ／ｇ银量的Ａｇ－ＴＭＫ－ＳＤＳ三元络合物光导比色测定法；二是测定０．０１０—０．２５μｇ／ｇ银量的巯基棉分离富集微珠析出比色法。可在同一份试液中依次完成。前者检出限为０．００６μｇ／ｍｌ（Ｋ＝３）；测定铜、铅和锌矿石标样ＧＳＯ－Ｃｕ－１（含银３．８７μｇ／ｇ）、ＧＳＯ－Ｐｈ－１（含银１４．７μｇ／ｇ）和ＧＳＯ－Ｚｎ－１（含银１３．５μｇ／ｇ）中的银，ＲＤＳ（ｎ＝１１）分别为１．６％、３．７％和３．４％；后法可检出５ｎｇ／ｇ银；测定地球化学标样ＧＳＤ－３（含银０．５９μｇ／ｇ）中的银，ＲＳＤ（ｎ＝１１）为６．ｔ％。方法较为简便、快速、准确和灵敏。用光导比色计测定，结果准确度、精度均有较大改善，且与室内原子吸收法相当。故所定方法具有广阔的应用前景。

A new method has been developed for rapid field determination of 0. 010-50μg-g silver. The method consists of two independent yet correlated parts: one is Ag-TMK-SDS tribasic complex light-guide colorimetric determination methood for directly determining 0. 25-50μ/g silver,and the other is mercapto group isolation and enrichment micrcbead-separating colorimetry for determining 0. 010-0. 25μg/g silver. These two parts can be comploted successively in the same test liquid.The former has a detection limit of 0. 006μg/ml (k= 3), and for determining silver in copper, lead and Zinc standard ore samples GSO-Cu-1 (containing silver 3. 81μg/g), GSO-Ph- 1 (containing silver 14.7μg/g) and GSO-Zn-1 (containing silver 13. 5μg/g), RSD(n =11) values are 1.6%, some 3.7%and 3. 4 % respectively; the latter can detect 5 ng/g silver, and for determining silver in geochemical standard sample GSD-3 (containing silver 0. 5μg/g), RSD (n=11) is 6. 6 %. Tee method is fairly simple, convenient, accurate and sensitive. With a light-guide colorimeter, the determinations are remarkably improved in accuracy and precision, being equivalent to results obtained by atomic absorption method, and this suggests that the method has a bright future ill application.