Gas chromatography/tandem mass spectrometry with long-term alkaline transesterification for the determination of esters of monochloropropanediols and glycidol with fatty acids in edible vegetable oils and fats
Introduction. The article discusses the method of determination of 2-, 3-monochloropropanediol (2-MCPDE, 3-MCPDE) and glycidyl (GE) fatty acids esters in edible vegetable oils and fats by slow alkaline transesterification and GC-MS/MS. Many toxicological data showed these substances to have the potential for human health risks if consumed; in addition, existing determination methods have various limitations. So, there is a need to expand the variety of 2-MCPDE, 3-MCPDE and GE determination methods. Materials and methods. 2- and 3-MCPD esters, and glycidyl esters in their corresponding free forms were measured by slow alkaline transesterification with GC-MS/MS. Results. Multiple reactions monitoring mode parameters were optimized. Compared to SIM operating mode, MRM mode improved the selectivity and increased the signal-to-noise ratio. The method was linear in the range of 0.3 mg/kg - 30.0 mg/kg for each analyte. Recovery, tested in this range, was found to be 87.5%-113.6 %. Conclusion. The method discussed here was based on the ISO 18363-2: 2018 standard. In contrast to the last one, we used tandem chromatography-mass spectrometry to detect analytes and a method of absolute calibration with internal standards to quantitate them. In addition, it is proposed to analyze a spiked sample during the sequence of unknown samples to improve the quality of results.