Cyclopentadienylidenecarbonyl: the Major Primary Thermolytic Fragment of Salicylaldehyde

1971 ◽  
Vol 49 (22) ◽  
pp. 3602-3606 ◽  
Author(s):  
O. A. Mamer
Keyword(s):  
Temperature Dependence ◽  
Title Compound ◽  
Molecular Ions ◽  
Ion Source ◽  
Mass Spectrometric ◽  
Thermal Reactor ◽  
Helium Flow ◽  
Preparative Scale ◽  
Thermal Fragmentation ◽  
Chromatographic Mass

The thermal fragmentation of salicylaldehyde was studied from two aspects. Firstly, the temperature dependence of the intensity of the thermolytic fragment molecular ions was observed at 11 eV in the effluent from a helium flow thermal reactor attached through a helium separator to the ion source of a mass spectrometer. Secondly, the products of the thermolysis on a semi-preparative scale under trapping conditions were determined by coupled gas chromatographic – mass spectrometric analysis.The title compound is the major primary thermal fragment in this study and was trapped with methanol as carboxymethylcyclopentadiene.

Solvation of Cl− and O2− with H2O, CH3OH, and CH3CN in the gas phase

1973 ◽  
Vol 51 (15) ◽  
pp. 2507-2511 ◽  
Author(s):  
R. Yamdagni ◽  
J. D. Payzant ◽  
P. Kebarle
Keyword(s):  
High Pressure ◽  
Temperature Dependence ◽  
Gas Phase ◽  
Experimental Technique ◽  
Equilibrium Constants ◽  
Ion Source ◽  
Mass Spectrometric ◽  
Mass Spectrometric Detection ◽  
Free Energies

Determination of the temperature dependence of the equilibrium constants Kn,n−1 for the reactions A −Bn = A −Bn−1 + B where A− equals Cl− and O2− and B is HOH, CH3OH, or CH3CN leads to the corresponding ΔH0n−1, ΔG0n−1,n, and ΔS0n−1,n values. The experimental technique is based on mass spectrometric detection of ions escaping from a high pressure ion source. At n = 1, Cl− is solvated most strongly by methanol, then CH3CN and HOH. At higher n a cross over is observed with water becoming the best solvent. These results are in agreement with the positive transfer enthalpies and free energies for Cl− from the liquid solvents HOH → CH3OH and HOH → CH3CN reported in the literature.O2− is solvated more strongly than Cl− appearing thus as an ion of "size" intermediate between Cl− and F− Again CH3OH gives the highest interaction for n = 1, however for n > 1 water gives stronger interactions.

Gas Chromatographic/Mass Spectrometric Confirmation of Leucomalachite Green in Catfish (Ictalurus punctatus) Tissue

1995 ◽  
Vol 78 (4) ◽  
pp. 971-977 ◽  
Author(s):  
Sherri B Turnipseed ◽  
José E Roybal ◽  
Jeffrey A Hurlbut ◽  
Austin R Long
Keyword(s):  
Solid Phase Extraction ◽  
Ictalurus Punctatus ◽  
Solid Phase ◽  
Mass Spectrometric ◽  
Phase Extraction ◽  
Neutral Alumina ◽  
Ms Analysis ◽  
Solid Phase Extraction Cartridge ◽  
Leucomalachite Green ◽  
Chromatographic Mass

Abstract A gas chromatographic/mass spectrometric (GC/MS) method was developed to confirm the presence of leucomalachite green (LMG), a metabolite of the triphenylmethane dye malachite green (MG), in catfish tissue. Residues were isolated according to a previously described liquid chromatographic (LC)A/IS spectrometric analysis of MG and LMG in fish. In our isolation procedure, analytes are extracted from tissue with acetonitrile–buffer, partitioned into CH2CI2, and applied to neutral alumina and propylsulfonic acid solid-phase extraction cartridges. Before GC/MS analysis, extracts prepared for the LC determinative method are eluted from a cyano solid-phase extraction cartridge, extracted into organic solvent, and concentrated for GC/MS analysis. Selected ion monitoring was performed by using 5 diagnostic ions (m/z 330,329,253,210, and 165) of LMG. The method was validated by confirming LMG in tissue fortified with mixtures of MG and LMG (5 and 10 ng/g each) and in tissue from fish that had been exposed to low levels of MG.

Gas chromatographic-mass spectrometric confirmation of radioimmunoassay results for cannabinoids in blood and urine

1990 ◽  
Vol 46 (3) ◽  
pp. 219-230 ◽  
Author(s):  
A.J. Clatworthy ◽  
M.C.H. Oon ◽  
R.N. Smith ◽  
M.J. Whitehouse
Keyword(s):  
Mass Spectrometric ◽  
Chromatographic Mass
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