Determination of trinexapac-ethyl and its metabolite in wheat and soil by UPLC-MS /MS method

An ultra performance liquid chromatography-tandem mass spectrometric method was developed for the determination of trinexapac-ethyl and its metabolite trinexapac acid in wheat and soil. Residues were extracted from wheat straw,seed and soil with acetonitrile-0. 1mol / L phosphate,then cleaned-up by liquid-liquid extraction with sodium chloride,the water in extract was removed,and finally the upper acetonitrile was directly analyzed by ultra performance liquid chromatography-tandem mass spectrometry( UPLC-MS / MS) in a multiple reaction monitoring( MRM) mode via electrospray ionization. The method was validated at three fortification levels in wheat and soil. The validation results as follows: the correlation coefficients of the standard calibration curves for trinexapac-ethyl and trinexapac were all over 0. 999 in their own concentration ranges,the average recoveries of the two compounds were between 73. 8% and 98. 2%,with the relative standard deviations( RSD) of 0. 5% and 4. 8%; the limits of detection( S / N≥10) of trinexapac-ethyl and trinexapac were 0. 05 mg / kg and 0. 5mg / kg.