2-羟基-5-磺酸基苯基重氮氨基偶氮苯与铊(Ⅲ)显色反应的分光光度法研究

研究了 2 羟基 5 磺酸基苯基重氮氨基偶氮苯 (HSDAA)与铊 (Ⅲ )的显色反应 ,在TritonX 10 0存在下和 0 72～ 0 99mol·L-1 氨水介质中 ,铊 (Ⅲ )与HSDAA有高灵敏的显色反应 ,生成 1∶2红色配合物 ,最大吸收波长在 516nm处 ,铊量在 0～ 0 8mg·L-1 范围内符合比尔定律 ,表观摩尔吸光系数为 1 0 4× 10 5L·mol-1 ·cm-1 。在体系中加入酒石酸钠和氰化钠 ,可大大提高试剂的选择性 ,已用于合成水样中痕量铊的直接测定 ,结果令人满意

Spectrophotometric Study of Color Reaction of Chromogenic Reagent 2-hydroxy-5-sulfo-benzenediazoaminoazobenzene(HSDAA) with Thallium(Ⅲ)

The chromogenic reaction of the 2-hydroxy-5-sulfo-benzenediazoaminoazobenzene(HSDAA) with thallium was studied in this paper. In the presence of Triton X-100 and in ammonia medium of 0.72-0.99 mol.L-1, HSDAA reacts sensitively with thallium (III) to form a red complex with molar radio of 1:2. The apparent molar absorptivity is 1.04 x 10(5) L.mol-1.cm-1 at the maximum absorption wavelength of 516 nm. Beer's law is obeyed in the concentration range of 0-0.8 mg.L-1 Tl(III). Adding NaC4H4O6 and NaCN in the system can improve selectivity of the chromogenic agent greatly. The method has been applied to the direct determination of trace amounts of thallium in sample of synthetic water with satisfactory results.