荧光分光光度法测定痕量亚硝酸根-基于对劳氏紫的荧光猝灭作用

Fluorospectrophotometric Determination of Traces of Nitrite Ion By Its Fluorescence Quenching Effect on Thionine

摘要: 在盐酸介质中亚硝酸根能与劳氏紫发生重氮化偶联反应,基于劳氏紫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-荧光分光光度法测定痕量亚硝酸根的方法,线性范围为0.04~0.40 mg·L-1,用于泡菜样品中痕量亚硝酸根的测定,测得回收率在96%~104%之间.

Abstract: In a dil.HCl medium,the fluorescence of thionine was quenched by NO-2 due to diazotization reaction.The magnitude of decrease in fluorescence intensity (ΔF) measured at (λex) 602 nm and (λem) 622 nm,was directly proportional to the concentration of NO-2 ion in the range of 0.04-0.40 mg·L-1.The proposed method was used in the determination of trace amounts of NO-2 in samples of pickles,giving values of recovery in the range from 96% to 104%.