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1 引言 锑的光度法日渐增多。用三羟基荧光酮测定锑是一类重要方法。有人曾在较强酸度下用4,5-二溴苯基荧光酮(DBPF)测定锑,选择性虽高,但灵敏度尚不高(ε=(5.6～7.8)×10~4)。为寻找一种更为灵敏的方法,故本文研究了如题示的显色反应。结果表明,Sb(Ⅲ)与DBPF及CTMAB形成了灵敏度很高的稳定络合物,其λ_(max)为578nm,ε_(578)=3.96×10~5L·mol~(-1).cm~(-1),是锑的胶束增效光度法中最为灵敏的反应。用巯基棉分离富集锑,测定了铜合金中的痕量锑,得到了满意的结果。 2 实验部分 2.1 仪器与试剂 721型分光光度计;pHS-2型酸度计。锑标准溶液:用99.99％锑粉按常法配制成20.0及5.Oμg Sb(Ⅲ)/ml(硫酸介质);1.O×10~(-3)mol/L的DBPF乙醇溶液;5.O×10~(-2)2mol/L的CTMAB溶液;pH4.5缓冲溶液(六次甲基四胺-盐酸);1.0×10~(-2)mol/L菲啰啉(Phen)溶液;将自制巯基棉装入直径为8mm长约10cm的一端拉细出口内径为2～3mm的玻璃管中。试剂皆为AR级;皆用去离子水配制。 2.2 实验方法 移取适量的Sb(Ⅲ)标准溶液(或试液)于10ml容量瓶中,依次加入0.5ml Phen溶液,1.0ml CTMAB溶液,3滴2,4-二硝基酚,用HCl及NaOH溶液调至淡黄色。加入2.5ml pH4.5缓冲溶液,0.50ml的DBPF溶液,用水定容。置于70℃水浴中加热10min,取出,流水?
1 Introduction Antimony photometric method is increasing. Determination of antimony with trihydroxyfluorone is an important class of methods. Some people have been using strong acidity 4,5- dibromophenylfluorone (DBPF) Determination of antimony, the selectivity is high, but the sensitivity is not high (ε = (5.6 ~ 7.8) × 10 ~ 4). In order to find a more sensitive method, this paper studies the color reaction as shown. The results show that Sb (Ⅲ) forms stable complexes with DBPF and CTMAB with λ max of 578 nm and ε 578 of 3.96 × 10 -5 L · mol -1 .cm ~ (-1), is the most sensitive reaction of antimony micellar synergistic spectrophotometry. The antimony was separated and enriched with mercapto cotton, and trace amounts of antimony in the copper alloy were measured. Satisfactory results were obtained. 2 Experimental 2.1 Instruments and reagents 721 spectrophotometer; pHS-2-type pH meter. Antimony standard solution: 99.99% antimony powder according to the usual preparation of 20.0 and 5. Oμg Sb (Ⅲ) / ml (sulfuric acid medium); 1.O × 10-3 mol / L of DBPF ethanol solution; O × 10 -2 mol / L CTMAB solution; pH 4.5 buffer solution (hexamethylene tetramine-HCl); 1.0 × 10 -2 mol / L phenanthridine solution; The self-made mercapto cotton into the diameter of 8mm long about 10cm one end of the narrow outlet diameter of 2 ~ 3mm glass tube. Reagents are all AR grade; all with deionized water preparation. 2.2 Experimental Methods Pipette appropriate amount of Sb (Ⅲ) standard solution (or test solution) in 10ml volumetric flask, followed by the addition of 0.5ml Phen solution, 1.0ml CTMAB solution, 3 drops of 2,4-dinitrophenol, with HCl and NaOH solution adjusted to pale yellow. Add 2.5ml pH4.5 buffer solution, 0.50ml DBPF solution, with water volume. Placed in 70 ℃ water bath heated 10min, remove, running?