ChemInform Abstract: TRIMETHYLSILYL DERIVATIVES OF TITANIUM

AbstractA qualitative and quantitative procedure has been developed for the determination of humectants in manufactured tobacco by gas-chromatographic method with a flame ionization detector. It consists of extraction with methanol, concentration of the extract and treatment with Tri-Sil reagents. The operating gas-chromatographic conditions are set forth. Samples of tobacco containing glycerine, propylene glycol, diethylene glycol, triethylene glycol, 1-3 butylene glycol and sorbitol have been analysed with recoveries, for the first five ones, in the range of 95-104 %. In order to verify that each chromatographic peak corresponded to the relative glycol, with no interference by other silylated compounds, the mass spectra were obtained through the combination of gas-chromatography with mass spectrometry. The results achieved confirm, as far as tobacco is concerned, that the procedure is accurate and precise. The same method for the determination of humectants was extended to cigarette smoke. Even though this involves morecomplicated problems, as compared to tobacco, because of the presence of silylated compounds, it was found that, for certain glycols, the gas-chromatography of the trimethyl derivatives can be also used as a method of analysis. The mass spectra of some polyhydric alcohols are shown

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Strukturvergleich bei 9,10-Dihydro-9,10-anthrylen-Verbindungen des Magnesiums und des Alkylaluminiums / Comparison between the Structures of 9,10-Dihydro-9,10-anthrylene Compounds of Magnesium and Alkylaluminium

Zeitschrift für Naturforschung B ◽

10.1515/znb-1985-1115 ◽

1985 ◽

Vol 40 (11) ◽

pp. 1504-1510 ◽

Cited By ~ 7

Author(s):

Herbert Lehmkuhl ◽

Abdul Shakoor ◽

Klaus Mehler ◽

Carl Krüger ◽

Yi-Hung Tsay

Keyword(s):

Ring Size ◽

Coordination Geometry ◽

Chemical Behaviour ◽

Trimethylsilyl Derivatives ◽

Derivatives Of

In magnesium as well as in aluminium derivatives of anthracene (1−4, 8) and its trimethylsilyl derivatives (5, 6 and 11), the metals occupy the axial positions at C9 and CIO, to form five-, seven- or ten-membered metallacycles, respectively, in 1−3, 5, 6 and 11. It appears that the metalla-ring size, and thus the coordination geometry of the bridging metal is of influence upon the chemical behaviour.

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29Si-Kernresonanzuntersuchungen an N-Trimethylsilyl-substituierten Aminen und Amiden / 29Si Nuclear Magnetic Resonance Studies on N-Trimethylsilyl Derivatives of Amines and Amides

Zeitschrift für Naturforschung B ◽

10.1515/znb-1977-0212 ◽

1977 ◽

Vol 32 (2) ◽

pp. 163-166 ◽

Cited By ~ 39

Author(s):

B. Heinz ◽

H. C. Marsmann ◽

U. Niemann

Keyword(s):

Nuclear Magnetic Resonance ◽

Aromatic Amines ◽

Chemical Shifts ◽

Substituent Effects ◽

Electronic Charge ◽

Magnetic Resonance Studies ◽

Basic Character ◽

Silyl Derivatives ◽

Trimethylsilyl Derivatives ◽

Derivatives Of

The 29Si chemical shifts of several trimethyl silyl derivatives of amines and amides are measured and compared to other chemical and theoretical properties such as the basicities or the electronic charge on the nitrogen or the hydrogen of the N-H group of the amine or the amide. Whereas the 29Si chemical shift of saturated amines can be rationalized in terms of substituent effects, the shifts of aromatic amines show some dependency on the basic character of the amine. There seems to be little correlation between 29Si chemical shifts and electronic charge, but there is a similarity of 29Si with 1H chemical shifts of the NH group, which is interpreted as depending on anisotropy effects.

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Monolithic Spin Column: A New Extraction Device for Analysis of Drugs in Urine and Serum by GC/MS and HPLC/MS

Journal of AOAC International ◽

10.1093/jaoac/94.3.765 ◽

2011 ◽

Vol 94 (3) ◽

pp. 765-774 ◽

Cited By ~ 8

Author(s):

Akira Namera ◽

Masakata Nagao ◽

Akihiro Nakamoto ◽

Shota Miyazaki ◽

Takeshi Saito

Keyword(s):

Correlation Coefficient ◽

Cause Of Death ◽

Spin Column ◽

The World ◽

Extraction Device ◽

Derivatizing Reagent ◽

Trimethylsilyl Derivatives ◽

Derivatives Of ◽

Urine And Serum ◽

Good Agreement

Abstract A monolithic spin column was developed for the extraction of analytes from biological materials. This column was constructed by packing a monolithic silica disk into a spin column. Sample loading, washing, and elution of the target drugs were accomplished simply by centrifugation of the column. Opiates and benzodiazepines are abused throughout the world. Identification and quantification of these drugs is very important to solve crimes or the cause of death. Three opiates (morphine, codeine, and dihydrocodeine) were extracted from urine and serum by using the column. After conversion to trimethylsilyl derivatives of the opiates by vigorous mixing with the derivatizing reagent, the solution was subjected to GC/MS. A linear curve was observed for opiates from 10 to 2500 ng/mL in urine and 5 to 1200 ng/mL in serum, respectively (correlation coefficient > 0.996). For benzodiazepines, the hydroxyl metabolites of triazolam and etizolam were extracted from urine using the column, and the eluate was directly analyzed by HPLC/MS without evaporation. The LOD values were at the ppb level, with RSD values lower than 15%. The proposed methods were successfully applied to clinical and forensic cases, and good agreement of results was obtained compared to conventional methods.

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