Determination of ethanol in liquor by near-infrared spectrophotometry with flow injection

• Main Authors: Tipparat P., Lapanantnoppakhun S., Jakmunee J., Grudpan K.
• Format: Article
• Language: English
• Published: 2014
• Online Access: http://www.scopus.com/inward/record.url?eid=2-s2.0-0035896196&partnerID=40&md5=48e3689873de7a05e48109cc7ec16910; http://www.ncbi.nlm.nih.gov/pubmed/18968213; http://cmuir.cmu.ac.th/handle/6653943832/5024
• Institution: Chiang Mai University

A simple procedure for the determination of ethanol in a liquor by near-infrared (NIR) spectrophotometry with flow injection (FI) is proposed. A liquor sample is equilibrated off-line with dried chloroform to extract ethanol into the organic phase. The extract is injected into a carrier stream of dried chloroform passing through a home-made flow through cell (1 mm path length) sitting in a NIR spectrophotometer for continuous monitoring of absorbance at 2305 or 2636 nm. The ethanol content can be evaluated from a calibration established by a plot of change in absorbance versus concentration of ethanol standard solutions. Optimization of the system will be discussed. A calibration is linear in the range of 20-50% (v/v) ethanol. A throughput of 240 injections h-1 can be obtained. The procedure is validated by comparing the results with an analysis using gas Chromatography. © 2001 Elsevier Science B.V.