地球化学调查中,可以把砷作为一种探途元素或指示元素。这是因为,砷较容易被物理或化学作用所疏散,形成围绕矿石沉积物的原生及次生晕。 本文所推荐的方法是利用硝酸-硫酸进行消化,然后加入硫代硫酸铵、苯、盐酸,再按照Jewett等人的程序以氯化物形式将砷(Ⅲ)萃入苯层中。苯层在用碳酸氢钠和酒石酸钾钠浸渍过的滤纸中蒸发后,用X射线荧光分析法测定盘上的砷。 In geochemical surveys, arsenic can be used as an excursion or indicator element. This is because arsenic is more easily dispersed by physical or chemical action, forming primary and secondary halo around the deposit of ore. The method recommended here is digestion with nitric acid-sulfuric acid followed by the addition of ammonium thiosulfate, benzene, hydrochloric acid, followed by extraction of arsenic (III) into the benzene layer as a chloride following the procedure of Jewett et al. The benzene layer was evaporated in filter paper impregnated with sodium bicarbonate and sodium potassium tartrate, and the arsenic on the disc was measured by X-ray fluorescence analysis.