Development of multidimensional chromatographic technique for improved analysis of Thai food

Abstract

In this work, simple two-dimensional (2D) chromatographic technique was developed to separate compounds in highly complex sample. The technique is called LCxGC-MS, involving the use of liquid chromatography (LC) as the first dimensional separation technique and the conventional GC-MS as the second dimensional separation. In this work, the green curry paste was selected as the sample for the analyses since it has a complicated chemical profile that has not been investigated in detail before. The LCxGC-MS results were compared with that obtained from the conventional GC-MS in the aspects of the number of identified compounds and quality of the MS spectra of the compounds. The LCxGC-MS and the conventional GC-MS technique analysis could identify 106 and 63 compounds in green curry paste, respectively, by comparison between the experimental MS spectra with that from the NIST database. Moreover, the signal intensities obtained with LCxGC-MS is enhanced and less complex than that with GC-MS analysis. This allows compound identification with higher confidence as indicated by the higher MS match scores obtained with LCxGC-MS. The compounds in different classes and the odor active compounds were also reported and discussed. This investigation emphasizes that multidimensional chromatographic technique is more effective, accurate and reliable than onedimensional chromatographic technique.