碱性三苯甲烷类染料——乙基紫[C.I.№.42600(1957版)]已广泛用于萃取光度法,目前已建立了测定微量锑、铼、铊、硼、银、金、钽、碘和磷的方法。本文应用乙基紫作显色剂,找出溴汞酸与乙基紫形成的缔合物易为苯、甲苯所萃取,可用来比色测定汞。本文较详细地探讨了萃取比色的主要条件,其它离子的干扰,并做了岩石矿物中微量汞的分析。实验表明,本法在选择性、灵敏度、稳定性及重现性等方面均获得较满意的结果。 (一)主要试剂与仪器 1.乙基紫:Chroma,配制成0.015％水溶液,过滤后备用。 2.汞的标准溶液:准确称取光谱纯二氯化汞0.6768克溶于水,在1000毫升容量瓶中稀 Alkaline triphenylmethane dyes - ethyl violet [CI No. 42,600 (1957 edition)] has been widely used in the extraction spectrophotometry, has been established for the determination of trace amounts of antimony, rhenium, thallium, boron, silver, gold, tantalum, Methods of iodine and phosphorus. In this paper, ethyl violet was used as a chromogenic reagent to find out the association between bromine mercuric acid and ethyl violet is easily detected by benzene and extracted by toluene, which can be used for the colorimetric determination of mercury. In this paper, the main conditions of colorimetric extraction are discussed in detail, the interference of other ions and the analysis of trace mercury in rock minerals. Experiments show that this method obtains more satisfactory results in terms of selectivity, sensitivity, stability and reproducibility. (A) of the main reagents and equipment 1. Ethyl violet: Chroma, formulated as 0.015% aqueous solution, filtered and reserved. Mercury standard solution: Accurately weigh the spectrum of pure mercury dichloride 0.6768 grams dissolved in water, diluted in 1000 ml volumetric flask