卟啉配合物-巯基棉体系分光光度法测定中药中铅、镉、铜

Analysis of Pb(Ⅱ), Cd(Ⅱ) and Cu(Ⅱ) in Chinese Medicine by the System of Porphyrin Complexes and Sulfhydryl Cotton Fiber

研究了卟啉与铅、镉、铜的反应及配合物的电子吸收光谱。结合巯基棉分离富集方法 ,将此金属卟啉配合物体系成功地应用于中药中微量铅、镉、铜的测定。方法简便 ,测定体系抗干扰的效果好 ,灵敏度高。实际样品测定的RSD在 3 3%～ 9 6 %之间。样品加标回收率在 90 %～ 1 0 3%之间。

The reaction of α β γ δ tetra( p sulfophenyl)porphyrin(TPPS 4) with Pb(Ⅱ), Cd(Ⅱ) or Cu(Ⅱ) has been studied in this article, and the spectra of the Pb(Ⅱ) TPPS 4, Cd(Ⅱ) TPPS 4 and Cu(Ⅱ) TPPS 4 show the spectral absorption of these complexes with high sensitivity. The molar absorptivities of Pb(Ⅱ) TPPS 4, Cd(Ⅱ) TPPS 4 and Cu(Ⅱ) TPPS 4 are 2 5×10 5 L·mol -1 ·cm -1 , 5 2×10 5 L·mol -1 ·cm -1 and 4 2×10 5 L·mol -1 ·cm -1 , respectively. With the sulfhydryl cotton fiber separation enrichment method, this analytical system of porphyrin complexes has been successfully applied to determining the trace amounts of Pb(Ⅱ), Cd(Ⅱ) and Cu(Ⅱ) in Ginkgo bilobal leaves and tea leaves. The RSD of determining 10 -6 10 -7 g·g -1 Pb(Ⅱ), Cd(Ⅱ) or Cu(Ⅱ) in samples lies between 3 3% 9.6%, and the recovery of added standard lies between 90% 103%.The proposed analytical method has the advantage of high sensitivity, simplicity and high efficiency of interfere resisting.