2-(2-喹啉偶氮)-1,3-二羟基苯光度法测定环境样品中锰的研究

Study on spectrophotometric determination of manganese in environmental samples with 2-(2-quinolinazo)-1,3-dihydroxybenzene

研究了 2 ( 2 喹啉偶氮 ) 1,3 二羟基苯 (QADHB)与Mn2 + 的显色反应 ,在 pH 10的氯化铵 -氨水缓冲介质中 ,于水包油型 (O/W )微乳液存在下 ,QADHB与Mn2 + 反应生成 3∶1稳定络合物 ,λmax =5 60nm ,ε =8 3 8× 10 4 。在 2 5mL溶液中锰质量在 0～ 2 0 μg内符合比尔定律 ,方法用于环境样品中锰含量的测定 ,结果令人满意。

The color reaction of 2-(2-quinolinazo)-1,3-dihydroxybenzene(QADHB) with Mn^(2+) was studied.In the medium of NH_4Cl-NH_3·H_2O buffer solution (pH10)and in the presence of microemulsion [sodium dodecyl sulfonate(SDS)∶n-butylalcohol∶n-heptane∶water(10∶4∶1∶85)] QADHB can react with Mn^(2+) to form a stable (3∶1) complex.The apparent molar absorptivity is 8.38×10^(-4) L·mol^(-1)·cm^(-1) at 560 nm.Beer’s law is obeyed in the range of 0～20 μg/25 mL.This method can be applied to the determination of manganese in environmental sample with good results.