催化光度法测定不同芦荟提取液中微量锌

Catalytic spectrophotometric determination of microamount zinc in extracted solution of Aloe barbadensis

目的:研究催化光度法测定芦荟醇提取液、水提取液和芦荟消化液中微量元素锌的含量.方法:在表面活性剂聚山梨酯-80存在下,于pH 9.50氨-氯化铵缓冲溶液中,Hg2+催化加速Zn2+与meso-4(4-甲基,3-磺基苯基)卟啉(WTPS4)的显色反应.结果:Zn2+与TTPS4、聚山梨酯-80形成稳定的三元配合物,其ε=3.86×105,Zn2+浓度在0.005～0.100 mg·L-1范围内符合比尔定律,检出限为0.001 mg·L-1;芦荟消化液中锌含量＞芦荟醇提取液中锌含量＞芦荟水提取液中锌含量.结论:聚山梨酯-80对Zn2+与TTPS4显色有增敏,而Hg2+催化加速Zn2+与TTPS4显色反应,应用本法可直接测定7种芦荟提取液中锌含量,结果满意.

A new catalytic spectrophotometric method was applied to determine microamount zinc in Aloe barbadensis extracted with EtOH.H2O,or digested by HNO3-H2O2. METHODS In the presence of nonionic surfactant Tween -80 and NH3NH4Cl buffer of pH 9. 5,Zn^2＋ reacted with meso-tetra-（4-methyl-3-sulfonatehenyl） porphin（TTPS4 ）colourably using Hg^2＋ as catalyzer. RESULTS The complex had an absorption maximun at 430 nm,and its molar absorptivity was 3.86 ×10^5 ,Beer＇s law was obeyed in the concentration range of 0. 005 - 0. 100 mg·L^-1. The detection limit is 0. 001 mg· L^-1 content of zinc in digested Aloe barbadensis〉content of zinc in extracted EtOH solution of Aloe barbadensis〉content of zinc in extracted H2O solution Aloe barbadensis. CONCLUSION The method has been used for the determination of microamount zinc in extracted solution from Aloe barbadensis.