摘要
叶酸接受紫外光照后可转变成最大激发波长为 2 74nm、最大发射波长为 4 66nm的强荧光化合物。对光化学反应介质进行考察 ,发现在Na2 CO3 NaHCO3缓冲体系中所产生的光化学荧光最强 ,据此建立了流动注射在线光化学荧光分析法。试样在水载流的携带下与pH 9.5的Na2 CO3 NaHCO3缓冲溶液汇流后 ,通过一个盘绕在 6 W低压汞灯上的PTFE编结式光化学反应器。在反应器中所生成的荧光化合物直接通入荧光计的流通池测定荧光强度。在最佳条件下 ,动态线性范围可达 0 .0 0 1～ 4mg L ,检测限为 0 .1 6μg L,采样速率达80 h ,1 1次测定浓度分别为 0 .0 1和 0 .1mg L的叶酸标准溶液所得到的RSD分别为 1 .0 %和 0 .2 %。
Upon exposure to ultraviolet-irradiation folic acid was transformed to a strongly fluorescent compound with a maximum excitation wavelength of 274 nm and a maximum emission wavelength of 466 nm. Investigation into them medium for the photochemical reaction revealed that the most intensive photochemical fluorescence was induced in Na2CO3-NaHCO3 buffer. Based on these observations, a flow injection on-line photochemical spectrofluorimetry was developed. A sample band, carried by a water stream, was merged with a pH 9.5 Na2CO3 - NaHCO3 buffer stream. The mixed solution was driven to pass a knotted polytetrafluoroethylene photochemical reactor that was freely coiled around a 6-W low-pressure mercury lamp. The fluorescent compound produced in the reactor Was directly delivered to a flow-through-cell where the fluorescence intensity was measured. Under the optimized conditions a detection limit of 0.16 mug/L was achieved at the sampling rate of 80/h. Eleven determinations of standard solutions containing both 10 and 100 mug/L folic acid gave RSDs of 1.0% and 0.2%, respectively. Linear dynamic range was observed in the range of 1 similar to 4000 mug/L. The developed approach was successfully applied to the determination of folic acid in tablets.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2003年第2期229-231,共3页
Chinese Journal of Analytical Chemistry
基金
浙江省教育厅资助科研项目
关键词
流动注射
光化学荧光法
药物制剂
叶酸
维生素Bc
测定
folic acid
flow injection
spectrofluorimetry
photochemical reaction
pharmaceutical preparation
