一种快速检测中药材中二氧化硫残留量的荧光探针的合成及其应用

Synthesis and application of a fluorescent molecular probe for rapid detection of sulfur dioxide residues in traditional Chinese herbs

建立一种增强型（turn-on）罗丹明衍生物荧光探针检测HsO3-和硫磺熏蒸中药材中二氧化硫残留量的方法。此方法基于探针中的醛基和HSO3在pH4．8的水醇条件下发生加成反应，伴随有罗丹明衍生物中的螺内酰胺开环可使探针荧光明显增强，荧光增强程度与HS03-的浓度呈线性相关，线性范围0．005～20μmol／L，相关系数r=0．9985。此方法对HSO3-具有高灵敏度和选择性，检测限低至2．0nmol／L。常见的阴阳离子及还原性物质对HS0i的检测均没有干扰。此外，将此荧光探针用于检测硫磺熏蒸中药材二氧化硫残留量，操作简便、快速，回收率良好。

A fluorescence method based on a ＂turn-on＂ rhodamine derivative fluorescent probe was developed for the detection of hydrogen sulfite ions and sulfur dioxide residues in sulfur-fumigated herbs. This method was real- ized through a well-known aldehyde-bisulfite addition reaction accompanied by a ring opening of spirolactam of probe molecule in pH 4. 8 aqueous ethanol media which resulted in a significant fluorescence and color change. The fluorescence enhancement was linearly proportional to the concentrations of bisulfite ranging from 0. 005 to 20 μmol/L with a correlation coefficient of 0. 998 5. The detection limit was low as to 2.0 nmol/L and there was no interference with other familiar co-existing anions, cations and reducing reagents indicating high sensitivity and selectivity of the proposed method. In addition, the novel probe was successfully applied for the identification of sulfur dioxide residues in herbs with a satisfactory recovery in five real samples.