Gas chromatography coupled to mass spectrometry (GC-MS) is an essential instrument for high-throughput metabolomics studies especially for VOCs profiling. GC-MS utilizes a quadrupole mass spectrometer capable of high-speed scanning, which enables reliable and fast metabolites identification that are biologically relevant. Generally, samples are normally derivatized prior to GC-MS analysis in order to reduce their polarity and facilitate chromatographic separation. The electron ionization (EI) mass spectra obtained are reproducible and suitable for library matching, mass spectral collections being readily available.

Metabolomics is the study of identification and quantification of small molecules present in biological systems. It is a powerful tool comprises of analytical technologies and multivariate analysis for holistically probing large data sets. The massive development in equipment and software for data collection and analyses had led to rapid progress, with NMR and MS being the most important metabolomic platforms with wide applications in chemical, biological, pharmaceutical and medical sciences. High reproducibility is one of the fundamental advantages of NMR spectroscopy. NMR spectrometers are capable of analyzing the identity, structure, concentration, and behavior of molecules without destroying the samples. In addition, NMR metabolomics continues to make significant contributions to the identification of biomarkers to aid in the diagnosis and treatment of various diseases.