Application of two charge transfer complex formation reactions for selective determination of metformin hydrochloride in pharmaceuticals and urine

Future Journal of Pharmaceutical Sciences

Table 1 Results showing the effect of solvents on the absorbance of C-T complexes when 160 and 32 μg mL^-1 MEB used in the reaction in PCA and DDQ methods, respectively

Solvent	PCA method			DDQ method
Solvent	λmax^a, nm	Absorbance of blank at λmax	Absorbance of product of MEB and PCA at λmax	λmax^a, nm	Absorbance of blank at λmax	Absorbance of product of MEB and DDQ at λmax
Acetonitrile	530.0	0.013	0.496	460.0	0.006	0.520
Chloroform	525.0	0.014	0.232	450.0	0.018	0.315
Methanol	520.0	0.019	0.331	450.0	0.024	0.321
Ethanol	520.0	0.014	0.292	450.0	0.011	0.268
Acetone	520.0	0.014	0.232	445.0	0.017	0.260
1,4-Dioxane	520.0	0.018	0.124	450.0	0.019	0.160
Dichloromethane	525.0	0.023	0.212	450.0	0.022	0.302
Dimethylformamide	525.0	0.028	0.224	450.0	0.024	0.319