催化过氧化氢氧化邻苯三酚红固体基质室温燐光猝灭法测定痕量钴

Determination of Trace Cobalt by Solid Substrate Room Temperature Phosphorescence Quenching Method on Hydrogen Peroxide Oxidizing Pyrogallol Red

基于硼砂缓冲液中聚丙烯酰胺（PAM）存在下，邻苯三酚红（PGR）于滤纸固体基质上能发射强而稳定的室温烧光，PAM可活化钴离子催化H2O2氧化PGR反应，使PGR的室温磷光猝灭，从而建立了测定痕量钴的新方法。该方法的线性范围为4．8—960（×10^-18g／斑）Co^2＋（浓度范围0．012—2．40×10^-9g／L，0．4μL／斑），工作曲线的回归方程△Ip=12．76＋0．1248mC02＋（×10^-18g／斑），n=7，相关系数r=0．9993；检出限为1．2×10^-18g／斑（对应浓度为3．0×10^-12g／L）。对4．8和960（×10^-18g／斑）Co^2＋重复测定11次（0．4μL点样量），RSD分别为3．6％和4．7％。用PAM比不加PAM时△Ip增加4．6倍。本方法灵敏、准确、简便快速、重现性好，用于党参、当归、川芎、金银花和VB12中的痕量钴测定，结果满意。

In the presence of polyacrylamide （PAM） and borax buffer solution, pyrogallol red （PGR） can emit the strong and stable phosphorescence on filter paper. And cobalt activated by polyacrylamide can catalyze the reaction of hydrogen peroxide oxidizing PGR, which causes its phosphorescence quenching. Based on the facts above, a new method for the determination of trace cobalt has been established. The phosphorescence intensity decrement （Alp） is proportional to the content of Co^2＋ when the concentration of Co^2＋ is within the range of 4.8 - 960.0 （ × 10^-18g/spot） （corresponding concentration is 0. 012 - 2.40（ × 10^-9 g/L）, sample volume 0.4 μL/spot）. The regression equation of working curve is Alp = 12.76 ＋ 0. 1248 m Co^2＋ （ × 10 ^-18 g/spot）, with correlation coefficient r =0. 9993 （n =7） and a detection limit of 1.2 × 10 ^-18 g/spot （ corresponding concentration is 3.0 × 10 ^-12g/L）. RSDs are 3.6% and 4.7% for samples containing 4.8 and 960.0 × 10^-18 g/spot of Co^2＋ , respectively （n = 11, sample volume： 0.4μL/spot）. The Alp for the system with polyacrylamide is 4.6 times higher than that without polyacrylamide. This sensitive, simple, rapid and repeatable method has been applied to analyze the content of cobalt in ligusticum accurate, wallichii, angelica, honeysuckle, dangshen and vitamin B12 （VB12） with satisfactory results.