A Multi-pumping Flow System for Fast Spectrophotometric Determination of Simvastatin

A flow-based system with solenoid micro-pumps is proposed for fast simvastatin (SMT) determination in pharmaceutical preparations. The method is based on the inhibition of methyl orange bromination in the presence of the analyte with spectrophotometric detection. A linear response was observed between 5.0 and 35 mg L-1 SMT with a detection limit of 1.2 mg L-1 (99.7% confidence level). The coefficient of variation (n = 20) and sampling rate were estimated as 3.3% and 80 determinations per hour, respectively. Reagents consumption was estimated as 3.5 μg of NaBrO3, 9.5 μg of methyl orange and 400 μg of NaBr per determination, generating 4.5 mL of waste. The results for pharmaceutical samples agreed with those obtained by the reference chromatographic procedure at the 95% confidence level. The procedure is a fast, greener and reliable alternative for SMT determination.