Research Article Open Access

GC-MS Analysis and PLS-DA Validation of the Trimethyl Silyl-Derivatization Techniques

Kamalrul Azlan Azizan1, Syarul Nataqain Baharum1, Habtom W. Ressom2 and Normah Mohd. Noor3
  • 1 Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
  • 2 Department of Oncology, Georgetown Lombardi Comprehensive Cancer Center, Georgetown University, Medical Center, Washington, D.C., United States
  • 3 School of Bioscience and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia


Problem statement: Comparison and validation analysis of the conventional and power-adjusted Microwave-Assisted (MA) techniques of TMS derivatization using Gas Chromatography-Mass Spectrometry (GC-MS) and Multivariate Analysis (MVA) of Partial Least Squares Analysis (PLS-DA). Further improvement of the conventional technique using vigorous shaking was tested and analyzed. Approach: Cross-validation and response permutation test of PLS-DA and S-plot of Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA) was applied to the extracellular data of Lactococcus lactis, which was analyzed by GC-MS. The analyzed samples were firstly derivatized using Methoximination (MeOX) and N-methyl-N-trimethylsilyl fluoroacetamide (MSTFA) followed by conventional and power-adjusted Microwave-Assisted (MA) heating treatment. Results: The supervised PLS-DA applied to extracellular data failed to show the same clustering results between conventional and power-adjusted Microwave-Assisted (MA) techniques. It was suggested that the type of heating used in the derivatization techniques had affected the detection of groups of metabolites. Furthermore using the UV-scaling method, S-plot and Variable Importance for Projection (VIP), about 40 metabolites that were responsible towards the clustering and separation showed in PLS-DA score plots were successfully indicated. Conventional technique with vigorous shaking showed clear clustering according to groups compared to MA technique. Conclusion: Type of heating applied to the TMS derivatization showed effects towards the detection of metabolites where conventional technique indicated strong clustering compared to MA technique.

American Journal of Applied Sciences
Volume 9 No. 7, 2012, 1124-1136


Submitted On: 5 March 2012 Published On: 4 June 2012

How to Cite: Azizan, K. A., Baharum, S. N., Ressom, H. W. & Noor, N. M. (2012). GC-MS Analysis and PLS-DA Validation of the Trimethyl Silyl-Derivatization Techniques. American Journal of Applied Sciences, 9(7), 1124-1136.

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  • PLS-DA
  • L. lactis
  • TMS derivatization
  • Microwaved Assisted (MA)
  • Variable Importance for Projection (VIP)
  • Multivariate Analysis (MVA)
  • conventional technique