Quantitative analysis of blended oils by matrix-assisted laser desorption/ ionization mass spectrometry and partial least squares regression

Quantitative labeling of oil compositions has become a trend to ensure the quality and safety of blended oils in the market. However, methods for rapid and reliable quantitation of blended oils are still not available. In this study, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) was used to profile triacylglycerols in blended oils, and partial least squares regression (PLS-R) was applied to establish quantitative models based on the acquired MALDI-MS spectra. We demonstrated that this new method allowed simultaneous quantitation of multiple compositions, and provided good quantitative results of binary, ternary and quaternary blended oils, enabling good limits of detection (e.g., detectability of 1.5% olive oil in sunflower seed oil). Compared with the conventional GC-FID method, this new method could allow direct analysis of blended oils, analysis of one blended oil sample within minutes, and accurate quantitation of low-abundance oil compositions and blended oils with similar fatty acid contents.

Automated summary

This study developed a new method using MALDI-MS and PLS-R to quantitate triacylglycerols in blended oils, allowing simultaneous quantitation of multiple compositions with good limits of detection. The new method enables direct analysis of blended oils, rapid analysis of samples, and accurate quantitation of low-abundance oil compositions and blended oils with similar fatty acid contents, compared to conventional methods.