cyhexatin and triphenyltin

A method for the simultaneous determination of cyhexatin, triphenyltin and fenbutatin oxide residues in fruits and vegetables was developed by Grignard derivatization and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). The samples were firstly digested by HC1/THF (1 :10, v/v), then extracted by hexane and followed by the derivatization with Grignard reagent (EtMgBr). Then after purification using florisil SPE columns, the sample extracts were finally analyzed by GC-MS/MS. The qualitative and quantitative determinations of the three organotin pesticides were performed by the tandem mass in multiple reaction monitoring (MRM) mode. By using apple as a representative matrix, the limits of detection (LODs) obtained by the proposed method for cyhexatin, triphenyltin and fenbutatin oxide were 2. 0, 1. 5 and 3.4 μg/kg (as Sn), respectively. The average recoveries for the three organotin pesticides were in the range of 72.4%-107. 1% at the spiked levels of 10, 20, 50 and 200 μg/kg (as Sn) and the relative standard deviations (RSDs) ranged from 0. 4% to 14. 2%. The proposed method was validated to have good linearity, high sensitivity, selectivity and accuracy for the simultaneous determination of cyhexatin, triphenyltin and fenbutatin oxide in fruits and vegetables. The sensitivity of this method can meet the requirements of the inspection for the three organotin pesticides at the level of maximum residue limits (MRLs) set by China and some other countries.

Topics: Fruit; Gas Chromatography-Mass Spectrometry; Limit of Detection; Organotin Compounds; Pesticide Residues; Tandem Mass Spectrometry; Trialkyltin Compounds; Vegetables

In order to clarify the interaction mechanism between organotin compounds and organisms, the effects of these compounds on the development of a benthonic filter-feeding invertebrate were studied. Embryos of the ascidian Styela plicata were obtained in laboratory by cross-fertilization and their development was followed in vivo after incubation with 0.1, 1, and 10 microM organotin compounds for various exposure times. Moreover, embryos selected at opportune stages after incubation with 10 microM tributyltin (TBT) or triphenyltin (TPT) for 1 hr were observed at the electron microscope to recognize cell alterations. Results indicate that organotins significantly affect all stages of ascidian development in a dose- and time-dependent manner and the most sensitive stages are gastrula and neurula. These compounds are able to block development, giving rise to anomalous embryos with irreversible effects. The order of inhibition appears to be strongly dependent on the organotin liposolubility: TBT > dibutyltin (DBT) > monobutyltin (MBT) and TPT > tricyclohexyltin (TCHT). The mitosis block of blastomeres in the early stages may be related to an inhibition of the microtubule polymerization. Observations with light and electron microscopes reveal globeshaped blastomeres with large intercellular spaces in the morula and gastrula stages, suggesting a toxic damage with alteration of the cytoskeleton. Moreover, the occurrence of electron-dense precipitates of organotins in the inner membrane of mitochondria and morphological changes of their cristae suggest an inhibitory effect on oxidative phosphorylation which is conspicuous in the gastrula stage. In this stage, the size of the electron-dense aggregates grow from 50-70 to 110-170 nm, while at the same time the alteration of the cristae increases.

Topics: Animals; Cytoskeleton; Embryo, Nonmammalian; Female; Larva; Male; Microscopy, Electron; Mitochondria; Organotin Compounds; Solubility; Survival Rate; Trialkyltin Compounds; Urochordata