Determination of volatile components in ginger using gas chromatography-mass spectrometry with resolution improved by data processing techniques

Abstract

Ginger is widely used as either a food product or an herbal medicine in the world. In this paper, a method was developed for determining volatile components in essential oils from both dried and fresh ginger by use of gas chromatography-mass spectrometry (GC-MS) and chemometric approaches. With the resolution improvement by chemometric methods upon two-dimensional data from GC-MS, the drifting baseline can be corrected. In addition, the peak purity can be assessed and the number of chemical components and their stepwise elution in the peak clusters can be identified. The peak clusters investigated are then resolved into pure chromatograms and related mass spectra for each of the components involved. Finally, with the pure chromatograms and related mass spectra obtained, the chemical components can be qualitatively identified based on the similarity searches in the MS databases and the chromatographic retention times. Quantitative determination can be conducted using the overall volume integration approach. The results showed that 140 and 136 components were separated and that 74 and 75 of them were tentatively identified, which accounted for about 62.82 and 47.11% of the total relative content for dried and fresh ginger, respectively. In comparison with the chromatographic fingerprints of essential oils from dried and fresh ginger, 60 of the volatile components determined match with each other. The study demonstrated that the use of chemometric resolution based on two-dimensional data can mathematically enhance the separation ability of GC-MS and assist qualitative and quantitative determination of chemical components separated from complicated practical systems such as foods, herbal medicines, and environmental samples.