Spectrophotometric flow-injection method for determination of sorbic acid in wines

✍ Scribed by A. Rivero Molina; E. Vereda Alonso; M. T. Siles Cordero; A. García de Torres; J. M. Cano Pavón

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 121 KB
• Volume: 11
• Category: Article
• ISSN: 0895-7533
• DOI: 10.1002/(sici)1098-2728(1999)11:5<299::aid-lra9>3.0.co;2-n

✦ Synopsis

A simple, rapid, and accurate spectrophotometric flow-injection method was developed for the determination of sorbic acid in wines based on the oxidation of sorbic acid with K 2 Cr 2 O 7 /H 2 SO 4 at 100ЊC, followed by reaction of the resulting malonaldehyde with thiobarbituric acid, also at 100ЊC, to give a red product, the absorbance of which is measured at 532 nm. The method requires no prior distillation of the wine and allows a sampling rate of 40 per hour. The calibration graph was linear from 0 to at least 15 lg mL ‫1מ‬ (the linear correlation coefficient was 0.9997), and the detection limit (signal-to-noise ratio, 3) was 0.14 lg mL ‫1מ‬ . The relative standard deviation of ten replicate determinations was 1.58%. The method was applied successfully to the determination of sorbic acid in red and white wines.