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 3

Regression equation, correlation coefficient, 𝑡-test concentration ranges, detection limits, and RSD% direct and standard addition calibration curves of TC-Au complex by using uv-visible spectrophotometry.

Method	Regr. eq.; 𝑌=𝐵𝑥+𝐴	Correlation coefficient (𝑟)	Line range; (µg/mL)	D.L. (µg/mL)	𝑡-test statistic; (calcd)	Tabulated 𝑡-test two tailed 95% C.I.	RSD%; (𝑛=4)	Mean; Rec.%
TC-Au(III) complex
Direct	𝑌=0.0093𝑥−0.0080	0.9991	5–70	0.7403	0.3994	2.365	0.9617	100.780
Standard addition	𝑌=0.0115𝑥+0.1133	0.9989	5–70		0.8320	2.365	1.2855	103.970
TC-Hg(II) complex
Direct	𝑌=0.0100𝑥−0.037	0.9989	5–70	0.5867	0.4791	2.365	0.9617	100.950
Standard addition	𝑌=0.0102𝑥+0.0963	0.9986	5–70		1.2126	2.365	1.2854	103.103