Determination of ethanol in distilled liquors using sequential injection analysis with spectrophotometric detection Original Research Article

A sequential injection analysis method using spectrophotometric detection has been developed for the determination of ethanol in spirit samples. Low-cost reagents (0.2 M potassium dichromate and 4 M sulphuric acid) are used, and reagent usage is minimal (200 μl per analysis). The system is fully automated using software written in LabVIEW™. The method is linear up to 6% (v/v) (R2=0.9995) with a detection limit of 0.09% (v/v). RSDs (n=10) are <1% in the range 1–6% (v/v) and the sample throughput is 19 samples h−1. Measured results for commercial spirit samples were in excellent agreement with their advertised ethanol strengths.