Determination of Tetracycline in Pharmaceutical Preparation by Molecular and Atomic Absorption Spectrophotometry and High Performance Liquid Chromatography via Complex Formation with Au(III) and Hg(II) Ions in Solutions

Table 4

Percentage relative error for determination of TC-Au(III) and TC-Hg(II) complexes by direct and standard addition UV-vis methods.

Complex	State of drug	Stated concentration (mg/unit)	Found direct calb.; (mg/unit)	% Erel	Found st. add. calb.; (mg/unit)	% Erel
TC-Au(III)	Capsule	250	251.950	+0.780	259.925	+3.970
TC-Hg(II)	Capsule	250	252.375	+0.950	257.757	+3.103