ISOSBESTIC DUAL WAVELENGTH SPEOTROPHOTOMETRIC SIMULTANEOUS DETERMINATION OF ZINC AND OADMIUM USING meso-TETRAKIS[4-(TRIMETHYLAMMONIUM) PHENYL] PORPHINE

Iin this paper an isosbestic dual--wavelength spectrophotometric method for the simultaneous determination of zinc and cadmium using meso--tetrakis [4-(trimethylammonium) phenyl] porphine has been developed. The interference from excess of reagent was masked by adding lead ions solution.The molar absorptivities (Ae) for zinc and cadmium were 6. 54 × 105 and 4. 27 × 105 L. mol-1. cm-1,respectively. The method could be used to determine zinc and cadmium in synthetic mixtures, and the satisfied results were obtained.

双波长分光光度法测定芦荟苷的含量

目的 :应用等吸收点双波长分光光度法对芦荟中芦荟苷含量测定进行研究。方法 :依据芦荟苷与芦荟大黄素的光谱特征 ,选择 36 1.4nm为测定波长 ,480 .9nm为参比波长。结果 :芦荟苷线性范围 1× 10 -6～ 1× 10 -4 mol/L ,回收率为 97.4%～10 1.6 % ,RSD为 0 .5 5 %～ 0 .74% ,芦荟大黄素对测定不干扰。结论 :本方法简便可靠 ,重现性好 。