mass spectrometry

A method for determining the 20 pesticides (azoxystrobin, boscalid, chlorpyrifos, cyprodinil, diazinon, dimethoate, fluazifop-P-butyl, malathion, metribuzin, penconazole, phosalone, pirimicarb, piri- miphos-methyl, prometryn, propargite, pyraclostrobin, pyrimethanil, triadimenol, triadimefon, trifloxystrobin) in grapes and tomatoes by high performance liquid chromatography with tandem quadrupole – time of flight mass spectrometry detector (HPLC-MS / TOF), using sample preparation QuEChERS.

In this paper the high efficiency of the anionic absorbent polymer in the sorption and desorption of samples of aqueous solutions of organic substances. Recommended that the optimal conditions for use as a sorbent sample of water objects of the environment in the process of chemical and analytical monitoring of environmental pollutants of natural and anthropogenic origin.

We found that under laser desorption and ionization conditions, quercetin, belonging to the flavonol family, undergoes a decay, which occurs through a photoinduced reaction followed by dimerization of the forming biradical and by the subsequent fragmentation of the dimer. Naringenin, belonging to the flavonone family, also undergoes similar fragmentation, but owing to the lack of conjugation in the C ring, the forming biradical particle is not capable of further dimerization in the same way as observed for quercetin because of its low stability.