1-(4-安替比林)-3-(对苯磺酸)三氮烯光度法测定废水中镉(Ⅱ)

Spectrophotometric determination of cadmium in wastewater with 1-(4-antipyrine)-3-(sulfanilic acid)-triazene

探讨了1-(4-安替比林)-3-(对苯磺酸)三氮烯(ASTA)与镉的反应,建立了直接测定废水中镉的光度分析方法。试验表明,在硼砂-氢氧化钠介质中,镉与ASTA形成1∶2的红色络合物,该络合物的最大吸收峰位于505nm,表观摩尔吸光系数为2.7×105 L.mol-1.cm-1。10mL溶液中,镉量在0.3～5.0μg之间符合比尔定律,检出限为0.1mg/L。方法已用于电镀废水样中镉的测定,结果与原子吸收光谱法相一致,方法的回收率在104%～105%之间,相对标准偏差(n=6)小于3.9%。

The reaction of 1-（4-antipyrine）-3-（sulfanilic acid）-triazene（ASTA） with cadmium was studied to establish a direct photometric determination of cadmium in wastewater.The results showed that in the mixed medium of Na2B4O7-NaOH,cadmium reacted with ASTA to form a 1∶2 red complex.The complex had maximum absorption at 505 nm with the apparent molar absorptivity of 2.7×105 L·mol-1·cm-1.0.3-5.0 μg of Cd（Ⅱ） obeyed Beer＇s law in 10 mL of solution and the detection limit was 0.1 mg/L.This method had been applied to the determination of cadmium in wastewater samples, whose results were in consistency obtained by AAS method.Recovery was in the range of 104%-105% and the RSD（n=6） was lower than 3.9%.