Spectrometry Data Research Articles

Etude chimique et spectroscopique du système B(SCH3)3–B(NCS)3

Reaction of trimethylthioborate, B(SMe)3, with triisothiocyanatoborane, B(NCS)3, at room temperature gives mixtures containing B(SMe)3, the mixed compounds B(NCS)(SMe)2 and B(NCS)2(SMe) in low concentration, and association compounds. The previous compounds cannot be isolated due to equilibria being set up. Mass spectrometry, infrared and nmr data are reported. Structures involving S–B donor–acceptor bonds between the monomers are proposed for the association compounds {B(NCS)2(SMe)}2, {B(NCS)2(SMe)}2{B(NCS)3}, and {B(NCS)2(SMe)}2{B(NCS)3}2. Reaction of these compounds with trimethylamine yields Me3NB(NCS)3 and Me3NB(NCS)2(SMe). The same reaction with dimethylsulphide is incomplete and yields only Me2SB(NCS)3. Acidity strength decreases in the order B(NCS)3 > B(NCS)2(SMe) > B(NCS)(SMe)2 > B(SMe)3. This trend explains why dimerization of B(NCS)2(SMe) occurs whereas B(NCS)(SMe)2 is unassociated.

Reconstruction of gas chromatograms from interferometric gas chromatography/infrared spectrometry data

Reconstruction of gas chromatograms from interferometric gas chromatography/infrared spectrometry data

Methods to Determine Phytopharmaceuticals in Tobacco and Tobacco Products. 4th Report: A Procedure to Determine Vamidothion and its Metabolites/Methoden zur Bestimmung von Phytopharmaka in Tabak und Tabakerzeugnissen: IV. Mitteilung: Ein Bestimmungsverfahren fuer Vamidothion und seine Metaboliten

AbstractBased on previous work (7) a method to simultaneously determine vamidothion [I], vamidothion-sulfoxide [II] and vamidothion sulfone [III] in tobacco has been developed. The compounds are extracted with water/acetone/acetic acid from the tobacco, cleansed over an aluminium oxide column and then determined on the gas chromatograph with the specific sulphur detector. Rates of recovery are 70 % - 92 %, the determination level is 0.1 ppm. Mass spectrometry and nuclear magnetic resonance data of vamidothion [I], vamidothion-sulfoxide [ II ] and vamidothion-sulfone [III] are given.

Extraction of mass spectra free of background and neighboring component contributions from gas chromatography/mass spectrometry data

Extraction of mass spectra free of background and neighboring component contributions from gas chromatography/mass spectrometry data