HPLC determination of glyoxal in aldehyde solution with 3-methyl-2-benzothiazolinone hydrazone

Based on the absorption property of a diazine that can be formed by reaction of glyoxal and 3-methyl-2-benzothiazolinone hydrazone (MBTH) in the Ultraviolet-visible (UV-vis) spectral region, a HPLC method was developed for the determination of glyoxal in acetaldehyde solution. Glyoxal was derivatised from MBTH and the derivatives (diazine) were analyzed by HPLC for identification and quantification. The determination was performed on a ZORBAX Eclipse XDB-C18 column (4.6 × 250 mm, 5 μm) at 35°C with an injection volume of 10 μL, using a mixture of acetonitrile-water solvent (99:5, v:v) as a mobile phase with a flow rate of 0.8 mL·min−1. The proper derivative reaction conditions were the temperature of 70°C, MBTH to carbonyl molar ratio of 12, and reaction time of 110 min. The glyoxal diazine was a yellow dye with a maximum molar absorptivity at 401 nm and its retention time was 5.2 min under optimal HPLC conditions. The standard curve for glyoxal had a strong linear relationship with a regression coefficient (R2 = 0.999) in the range of 0.002–0.020 g·L−1. The analysis of glyoxal in an oxidising solution gave accurate results with a relative standard deviation (RSD) value of 0.55%. The average relative recovery was 102%. This efficient HPLC technique is also proposed for detecting other dicarbonyl compounds besides glyoxal.