Development of an analysis method for determination of residues and metabolite in rice and oat by ultra-high performance liquid chromatography coupled to tandem mass spectrometry

In this study, a new method was developed for the analysis of the residues and their metabolites of 8 mycotoxins in rice and oat by ultra-high performance liquid chromatography tandem mass spectrometry. All analytes were extracted using "dilute and shoot" and first step QuEChERS extraction. The developed method was validated to test the reliability of the analyses. Solvent composition and volume, shaker speed and time were optimized in dilute and shoot method to obtain the highest yield. QuEChERS extraction was performed according to EN 15662 method. The optimum conditions were determined in terms of composition of the mobile phase, flow rate, column temperature, injection volume and gradient composition in liquid chromatography. Sheath and auxiliary gas flow rates, capillary and vaporizer temperatures and spray voltage were optimized to detect the analytes in high selectivity and sensitivity in mass spectrometry. Linearity, dynamic range, selectivity, limit of detection, limit of quantification, accuracy and precision were determined in method validation. As a result of the research, while maximum 99.0% of the analytes can be extracted with the 1st Step QuEChERS method, this rate is 98.4% in the dilute and shoot method. The fact that the recovery values and relative standard deviation values are close to each other in both methods indicates that the dilute and shoot method can be used successfully instead of the QuEChERS method, thus saving the cost of the extraction kit. In addition, in both methods, time and cost were saved by preparing samples without a cleaning step. Data obtained as a result of method validation showed that this method is suitable for analysis of trace amounts of analytes with high selectivity, accuracy and precision.