Chlormequat and mepiquat are growth regulators. They delay the cells’ longitudinal growth, which has the effect of strengthening the grain’s haulm. In the case of stone fruits, the use of growth regulators promotes formation of fruit, and the strengthening of the stems delays early falling of fruit. Chlormequat and mepiquat are determined using mass spectrometry with electrospray ionisation on the basis of characteristic disintegration of the quasi-molecule ions.
Fig 1: Chormequat’s two characteristic mass transfers:
1st transfer m/Q -> m/Q 58
|Fig 2: Active ingredient standard solution (0.2 mg/kg)||Fig 3: Grain samples (0.2 mg/kg)|
Fig 4: Chlormequat full scan spectrum with QTRAP technology (from 1 precursor ion)