Gas‐chromatographic headspace analysis of phenol and cresols in soils by direct acetylation

Abstract

SummaryA quick, simple and selective procedure has been developed for the determination of phenol, o-cresol, m-cresol, and p-cresol in soil samples. The method is based on the gas chromatographic headspace analysis of phenols as acetate derivatives. These acetates were prepared directly in the wetted soil samples by acetic anhydride in the presence of KHCO3. With this procedure sample handling is reduced to a minimum as desorption and derivatization of the analytes are developed from the wetted samples inside the vial of the head space sampler. The acetate esters were analyzed using a 60 m x 0.56 mm DIIDP capillary column (di-isodecyl-phthalate), using 2-chlorophenol as an internal standard. The detection limit was between 0.03-0.08 pg g-' for the different species considered. Soil samples having carbon contents lower than 5 % can he analyzed by the proposed procedure.

Validated High Resolution Mass Spectrometry-Based Approach for Metabolomic Fingerprinting of the Human Gut Phenotype

“…The following 9 compounds could not be detected: phenol, p-cresol, cholesterol, glycolic acid, oleic acid, linoleic acid, meso-erythrol, citrazinic acid, and piperidine. In general, phenol and p-cresol detection are described by GC/MS following derivatization. , Glycolic acid and meso-erythrol could only be detected upon direct infusion. These compounds were most likely too polar to be retained by the HSS T3 column.…”

“…According to the FDA, a CV of 15% from the nominal value is acceptable for a single bioanalytical test, when operating closely to the limit of quantification, 20% remains acceptable. 37 The calculated recoveries were between 97.2% ± 7.1% and 104.8% ± 8.5% taking a CV range of 0.4 to 8.1% into account. The individual validation data are summarized in Table S2.…”

“…In general, phenol and p-cresol detection are described by GC/ MS following derivatization. 35,36 Glycolic acid and mesoerythrol could only be detected upon direct infusion. These compounds were most likely too polar to be retained by the HSS T3 column.…”

Simultaneous determination of ammonia, aliphatic amines, aromatic amines and phenols at µg l–1 levels in environmental waters by solid-phase extraction of their benzoyl derivatives and gas chromatography-mass spectrometry

“…13 Separation of phenols by GC is often inadequate and characterized by the occurrence of broad and tailing peaks. [14][15][16] Although it is possible to minimize the problem of peak tailing due to interactions of aromatic amines with active sites in the injector or the column, it is tedious to maintain good peak shape. [17][18][19] Derivatization is therefore recommended to enhance extraction efficiency and improve chromatographic performance.…”

“…[17][18][19] Derivatization is therefore recommended to enhance extraction efficiency and improve chromatographic performance. 20 Acetylation is the most common derivatization method for the determination of phenols by GC-FID 14,15 or GC-MS. 16,21 Nuclear bromination of aromatic amines 19 or replacement of the amino group by iodine 17,18 has been used with GC-ECD. Iodinated aromatic compounds have much greater electron affinity, at least by a factor of 150, 17 than other haloaromatics.…”