RESUMO
Palladium on carbon-ethylenediamine complex [Pd/C(en)] catalyzed deuteration of N(6)-benzyladenine-d(5), which is a plant growth regulator, to introduce 5 deuterium atoms, while use of Pd/C as a catalyst led to a complete removal of N(6)-benzyl group. The corresponding deuterated N(6)-benzyladenine was successfully used as a surrogate compound for the quantitative analysis of residual benzyladenine in crops using LC/MS/MS.
Assuntos
Cinetina/análise , Cinetina/síntese química , Reguladores de Crescimento de Plantas/análise , Reguladores de Crescimento de Plantas/síntese química , Compostos de Benzil , Cromatografia Líquida , Deutério , Cinetina/química , Reguladores de Crescimento de Plantas/química , Purinas , Espectrometria de Massas em TandemRESUMO
A simplified method for the determination of benzylaminopurine in agricultural products by LC/MS was investigated. Benzylaminopurine in agricultural products was extracted with acetone and the extract was concentrated to below 30 mL. Buffer solution of pH 9.0 and ethyl acetate were added to the residue, and the solution was shaken. The ethyl acetate layer was evaporated to dryness, and the residue was dissolved in acetone-n-hexane (1 : 1). The solution was applied to a SAX/PSA mini-column, which was then rinsed with acetone-n-hexane (1 : 1). Benzylaminopurine was eluted with acetone-n-hexane (1 : 1) containing 1% water. The eluates were evaporated to dryness, and the residue was dissolved in 10 mmol/L ammonium acetate-methanol (1 : 1). Benzylaminopurine was analyzed by LC/MS. The MS detection was performed in the selected ion monitoring (SIM) mode, with detection of the M+H(+) ion of benzylaminopurine (m/z 226) generated by electrospray ionization (ESI). Recoveries of benzylaminopurine from 15 agricultural products were in the range of 83.1-97.2%. The limits of detection (S/N=3) of benzylaminopurine in all samples except green tea and in green tea were 0.0003 and 0.0012 microg/g, respectively.
Assuntos
Compostos de Benzil/análise , Produtos Agrícolas/química , Purinas/análise , Cromatografia Líquida/métodos , Espectrometria de Massas/métodosRESUMO
Recently, there has been substantial interest in the new high-pressure polymorphs of GeO2 synthesized in the laboratory. Previous investigators reported the synthesis of 'CaCl2-type', 'alpha-PbO2-type' and 'pyrite-type (modified-fluorite-type)' GeO2 at pressures of 30-130 GPa in laser-heated diamond anvil cells. In order to provide definitive information about the new high-pressure polymorphs, we performed Rietveld refinements of the structures. The structure refinements confirm that two of these high-pressure phases do have the alpha-PbO2-type and pyrite-type (modified-fluorite-type) structures.
