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

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 mul per analysis). The system is fully automated using software written in LabVIEW(TM). The method is linear up to 6% (v/v) (R-2 = 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. (C) 2003 Elsevier B.V. All rights reserved.