Rapid and quantitative determination of urea in milk by reaction headspace gas chromatography

Abstract In this paper, an efficient and robust technique based on reaction headspace gas chromatographic analysis for the quantification of urea in milk is presented, which is realized by measuring formed carbon dioxide from the enzymatic hydrolysis of urea under the catalysis of enzyme urease. It was observed that the headspace equilibration was finished in 40 min at 35 °C. The new technique was proved to be accurate (relative errors ≤7.17%) and precise (relative standard deviations ≤2.93%). In addition, compared with the reference spectrophotometric technique, the new technique has a higher sample throughput. The proposed approach is simple, fast and has the potential to be a practical tool for the batch analysis of urea in milk production and processing.