ISSN:
1076-5174
Schlagwort(e):
Chemistry
;
Analytical Chemistry and Spectroscopy
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
Relative response factors (molar sensitivities relative to dibutyl phthalate) for homologous series of n-alkanes (C12—C26), trimethylsilyl esters of C10—C20 fatty acids (FAs) and bistrimethylsilyl derivatives of C8—C16 ω-hydroxy fatty acids (HOF As) were determined by integration of total ion chromatograms obtained using a conventional gas chromatograph-mass spectrometer in the electron impact ionization mode. For the alkanes up to C22 and for the FA-TMS derivatives up to C18 (C21 including the TMS carbons), response factors increased linearly with total number of carbons (r2 〉 0.99). The slope of this correlation (response factor = 0.0775n - 0.338, where n is the total number of carbon atoms in each analyte) is essentially identical with those determined in earlier studies for smaller molecules not containing silicon. For the HOFA derivatives up to C14 (C20 including TMS carbons), the molar response factors also increased linearly with total number of carbons, but for reasons not yet apparent the regression line for these homologs was different (response factor = 0.0330n + 0.456; r2 〉 0.99). Response factors for higher homologs in all three series fell below the regression line for the lower homologs, the deviation increasing with increasing molecular mass and increasing GC retention time. In all three series the upper limit to the linear portion of the correlation corresponded to the homolog whose GC retention time was ca 15 min under the conditions used; a high injection port temperature was found to be the most critical factor in extending the linear range of the correlation.
Zusätzliches Material:
2 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/jms.1190300711
Permalink
