催化固体基质室温燐光法测定痕量硒

Catalytic Solid Substrate-room Temperature Phosphorescence Method for Determination of Trace Selenium

基于HCl-KCl缓冲溶液和100℃反应20min条件下，氯酸钾能氧化苯肼（R1）生成氯化重氮离子，进而与1，2-二羟基萘-3，6-二磺酸（R2）作用生成红色偶氮化合物的反应，而红色偶氮化合物在滤纸基质上发射强而稳定的固体基质室温燐光（RTP），Se（Ⅳ）可催化氯酸钾氧化R1与R2之间的反应，结果导致RTP急剧增强，从而建立了催化氯酸钾氧化R1-R2体系固体基质室温燐光法（SSR TP）测定痕量硒的新方法．在最佳条件下，Se（Ⅳ）的量为1．60～320 fg／斑（浓度范围0．0040-0．80ng／mL，0．40μL点样量）与发射光强度的△Ip值成线性关系，工作曲线的回归方程△Ip=13．12＋0．4839m Se（Ⅳ）（fg／斑），n=6，相关系数r=0．9991，检出限为0．28fg／斑（对应浓度为7．0×10^-13gSe（Ⅳ）／mL（n=11）。对0．0040和0．80ng／mL Se（Ⅳ）分别进行11次的测定，其RSD为2．8％与3．5％．该方法重现性好、灵敏、准确，用于蛋黄与枸杞子中硒含量的测定，结果满意．同时讨论了催化SSRTP机理．

A new method for the determination of trace selenium based on solid sobstrate-ronm temperature phosphorimetry （SSRTP） has been established. This method was based on the fact that in HCl-KCl buffer solution, potassium chlorate could oxidize phenyl hydrazine to form chloridize diazo-ion after being heated at 100℃ for 20 rain, and then the diazo-ion reacted with 1, 2-dihydroxynaphthalene-3, 6-disullonic acid to form red azo-compoand which could emit strong room temperature phosphorescence （RTP） signal on filter paper. Selenium could catalyze potassium chlorate oxidizing the reaction between phenyl hydrazine and 1, 2-dihydroxynaphlhalene-3, 6-disnlfonic acid, which caused the sharp enhancement of SSRTP. Under the optimum condition, the relationship between the phosphorescence emission intensity （△Ip） and the content of selenium obeyed Beer＇s law when the concentration of selenium is within the range of 1.60-320 fg spot-t （or 0.0040-0.80 ng/mL with a sample volume of 0.4 μL）. The regression equation of working curve can be expressed as△Ip = 13.12 ＋ 0.4839 m Se （Ⅳ） （fg spot-1） （n = 6）, with correlation coefficient r = 0.9991 and a detection limit of 0.28 fg spot-1 （corresponding to a concentration range of 7.0×10^-13 g/mL Se （Ⅳ）, n = 11）. Alter Ⅱ-told measurement, R.S.D. was 2.8 and 3.5%, for the samples containing 0.0040 and 0.80 ng/mL of Se （IV）, respectively. This accurate and sensitive method with good repeatability has been successfully applied to the determination of trace selenium in Chinese wollberry and egg yolk with satisfactory results. The mechanism of the enhancement of phosphorescence was also discnssed.