硫堇荧光猝灭法测定痕量亚硝酸根  

Determination of Trace Amount of Nitrites by the Quenching Effect on the Fluorescence Emitied by Thionine

作　　者：沈荣[1] 刘琴芳 

机构地区：[1]安徽职业技术学院化工系,合肥230051 [2]国家农副加工食品质量监督检验中心,合肥230050

出　　处：《安徽职业技术学院学报》2008年第3期8-9,共2页Journal of Anhui Vocational & Technical College

基　　金：安徽省高等学校自然科学研究项目(KJ2007B226)

摘　　要：文章研究了在稀硫酸介质中亚硝酸根与硫堇发生的重氮化反应，基于硫堇的荧光强度随亚硝酸根的加入量增加而明显降低的现象，建立了荧光猝灭法测定痕量亚硝酸根的新方法。方法的激发波长为530nm，发射波长为620nm。在硫酸浓度为0．1mol／L，反应时间为30min的条件下，硫堇的荧光强度与亚硝酸根的加入量在10-240μg／L NO2^-间存在线性关系，方法的检出限为6．3μg／L NO2^-。方法操作简便，反应迅速，灵敏度高，已用于水样中痕量亚硝酸根的测定，并对反应的机理进行了讨论。A new fluotescence quenching method has been developed to determine nitrite in water samples. The method is based on the diazo-reaction between nitrite ion and thionine in dilute sulfuric acid medium. The fluotescence intensity is measured at excitation and emission wavelengths of 530nm and 620nm, respectively. The optimum experimental conditions have been confirmed and the concentration of suifuric acid is 0. 1 mol/L, the reaction time was 30 min. Under the selected conditions, the relationship is obtained between the fluorescence intensity and nitrite concentration in the range 10-240 μg/L NO2^-. The detection limit is 6.3μg/L NO2^-. The method is applied to detertime trace nitrite in water samples. The mechanism involved in the reaction is also discussed.

关 键 词：荧光猝灭法 硫堇 亚硝酸根 水样 

分 类 号：O6-3[理学—化学]