【摘要】 <正> 作者在研究应用醌亚胺类碱性染料——酚藏花红(Phenosafranine,C.I.№.50200)萃取分光光度法测定汞和金的基础上,发现溴铊酸或氯铊酸络阴离子与酚藏花红阳离子在硫酸介质中形成红色的离子缔合物,易为混合溶剂环已烷+丁酮(3+2)所萃取,在529nm处有最大吸收,可用来萃取比色测定微量铊。本文较详细地研究了萃取比色的主要条件,其它离子的干扰情况,并将此法应用于烟灰和岩石矿物中的微量铊的分析,获得较满意的结果。更多还原

【Abstract】 A new sensitive spectrophotometric method for the determination of trace thallium was described. Phenosafranine reacts with TlBr₄^- to form a red colour association complex with an absorption maximum at 529 nm. The apparent a value at 529nm is 6. 65×10⁴ and the Sandell sensitivity is 3.1×10^-3μg/cm². The complex can be extracted into a mixture of cyclo-hexane-butanone（3: 2）. Optimum conditions for the extraction are found to be 5 drops of 30% hydrogen peroxide in 10 ml solution, 0. 5% ferric chloride, 0. 8N in sulfuric acid, 0. 02M in sodium bromide and 0. 03% of pheno-safranine, and extracting with 10. 00 ml of cyclohexane-butanone（3: 2）for 1. 5 min. Beer′s law is obeyed for 0 to 20μg/10 ml of thallium. The color of the extract is stable for up to 100 min at room temperature. From the results in determination of 1 ml aliquot of 10μg of Tl, the method gives a mean absorbance value of 0. 647 with a standard deviation of 4. 1×10^-3 absorbance unit and relative standard deviation of 0. 63%. The method is satisfactory for analysing Tl in flue ash and ores.更多还原