Determination of free fatty acids as pentafluorobenzyl esters by electron capture gas chromatography

Gyllenhaal, Olle; Brötell, Harald; Hartvig, Per

doi:10.1016/s0021-9673(00)87787-0

Cited by 71 publications

(18 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This finding was in accordance to that of Gyllenhaal et al [20] who postulated that alkylation rather than extraction was the rate-determining step in the extractive alkylation procedure. Figure 4 illustrates the effect of PFB-Br concentration on the HA response at pH 10 with 0.2 mol/L TBA.…”

Section: Optimizationsupporting

confidence: 93%

See 1 more Smart Citation

Analysis of urinary biomarkers for exposure to alkyl benzenes by isotope dilution gas chromatography-mass spectrometry

Marais

Laurens²

2005

J. Sep. Science

View full text Add to dashboard Cite

A validated GC-MS method for the analysis of urinary metabolites of alkyl benzenes is reported. Metabolites for exposure to toluene, xylene and ethylbenzene were analyzed simultaneously using stable isotope substituted internal standards. The method entailed acidic deconjugation of urine samples followed by extractive alkylation with pentafluorobenzyl bromide as alkylating agent. The resulting pentafluorobenzyl derivatives of ortho-, meta-, para-cresol, mandelic acid (MA), hippuric acid (HA) and ortho-, meta-, para-methylhippuric acid (MHA) were then quantified by SIM. Optimized reaction conditions for the extractive alkylation step are reported. The derivatives were found to be sufficiently stable for overnight batch analysis. The LODs were below 0.1 micromol/L for the cresols and below 1 micromol/L for MA and the HAs. Within-batch precision for o-MHA was 7%, for m-MHA 5%, for p-MHA 5.2% and below 5% for the rest of the analytes.

show abstract

Section: Optimizationsupporting

confidence: 93%

“…An increase in the phase transfer catalyst concentration did not have an influence on the reaction time, opposed to the effect of increased alkylating agent concentration. This was in agreement with Gyllenhaal et al [20] and as a rule of thumb an excess of alkylating reagent should be used wherever possible.…”

Section: Optimizationsupporting

confidence: 91%

Analysis of urinary biomarkers for exposure to alkyl benzenes by isotope dilution gas chromatography-mass spectrometry

Marais

Laurens²

2005

J. Sep. Science

View full text Add to dashboard Cite

show abstract

“…The pH of the aqueous phase is adjusted to ensure complete ionization of the acidic substance which is then extracted as an ion pair with a tetraalkylammonium hydroxide into a suitable immiscible organic solvent. When pentafluorobenzyl bromide is used as the alkylating reagent, some additional care is necessary since the reagent is unstable under some conditions used for extractive alkylation, as well as being a potent lachrymatory agent [503]. RCOCT + R 4 Various tetraalkylammonium ions are used to form extractable ion pairs including tetrabutyl-, tetrapentyl-and tetrahexylammonium.…”

Section: Variousmentioning

confidence: 99%

Sample Preparation for Chromatographic Analysis

Poole

1991

Chromatography Today

View full text Add to dashboard Cite

“…Pentafluorobenzyl (PFB) derivatives of carboxylic acids offer certain advantages over the traditional methyl esters in GC work (7,8). First, the PFB reagent forms esters of significantly higher boiling points than those of the methyl esters.…”

mentioning

confidence: 99%

Combined Determination of Poly-β-Hydroxyalkanoic and Cellular Fatty Acids in Starved Marine Bacteria and Sewage Sludge by Gas Chromatography with Flame Ionization or Mass Spectrometry Detection

Odham

Tunlid

Westerdahl

et al. 1986

Appl Environ Microbiol

View full text Add to dashboard Cite

Extraction of lipids from bacterial cells or sewage sludge samples followed by simple and rapid extraction procedures and room temperature esterification with pentafluorobenzylbromide allowed combined determinations of poly-p-hydroxyalkanoate constituents and fatty acids. Capillary gas chromatography and flame ionization or mass spectrometric detection was used. Flame ionization permitted determination with a coefficient of variation ranging from 10 to 27% at the picomolar level, whereas quantitative chemical ionization mass spectrometry afforded sensitivities for poly-p-hydroxyalkanoate constituuents in the attomolar range. The latter technique suggests the possibility of measuring such components in bacterial assemblies with as few as 102 cells. With the described technique using flame ionization detection, it was possible to study the rapid formation of poly- ,-hydroxyalkanoate during feeding of a starved marine bacterium isolate with a complex medium or glucose and correlate the findings to changes in cell volumes. Mass spectrometric detection of short

show abstract

Determination of free fatty acids as pentafluorobenzyl esters by electron capture gas chromatography

Cited by 71 publications

References 21 publications

Analysis of urinary biomarkers for exposure to alkyl benzenes by isotope dilution gas chromatography-mass spectrometry

Analysis of urinary biomarkers for exposure to alkyl benzenes by isotope dilution gas chromatography-mass spectrometry

Sample Preparation for Chromatographic Analysis

Combined Determination of Poly-β-Hydroxyalkanoic and Cellular Fatty Acids in Starved Marine Bacteria and Sewage Sludge by Gas Chromatography with Flame Ionization or Mass Spectrometry Detection

Contact Info

Product

Resources

About