Application of quantitative spectral deconvolution 1H NMR (qsd-NMR) in the simultaneous quantitative determination of creatinine and metformin in human urine†
Determination of residual creatinine and metformin in urine is essential for estimating creatinine clearance and monitoring the therapeutic effect of metformin, respectively, in type 2 diabetes mellitus (T2DM) patients. This report describes the validation of the quantitative spectral deconvolution 1H NMR method (qsd-NMR) and its application in simultaneous determination of creatinine and metformin concentrations in human urine. Two different approaches, namely, the single-individual and the mixture of standards, were successfully developed and validated against referenced concentrations. The method was subsequently tested for the determination of the two analytes in healthy human urine spiked with metformin. The results showed that the method was selective with high linearity, accuracy, and precision. The method based on the single-individual standard approach was more suitable for creatinine, while that based on the mixture of standards was more suitable for metformin quantitative determinations. The results suggested that the method is potentially useful in the determination of creatinine and metformin concentrations in the urine of T2DM patients undergoing metformin treatment.