title: Extraction of ergosterol from peaty soils and determination by high performance liquid chromatography.
abstract: The ergosterol content of soil can be used as an indicator of fungal activity. A method has been developed for the extraction and determination of ergosterol in organic soils, as part of a study to assess the correlation between fungal activity and the sequestration of metal pollutants. The moisture content of the soil affected the extraction process. Four consecutive extractions with methanol removed >95% of the ergosterol that can be obtained from the fresh sample (63% moisture) by exhaustive extraction. By freeze drying the soils prior to extraction (a) up to 35% more ergosterol was extracted after a single extraction, (b) >90% of the recoverable ergosterol was collected in two extractions and (c) the repeatability of the extraction was improved. Storage of soil extracts in the absence of light prevents degradation of ergosterol. A previously reported method for determination of ergosterol by HPLC has been improved by modification of the eluant composition. With 46% methanol/46% acetonitrile/8% dichloromethane, ergosterol was eluted with good resolution approximately 8 min after injection of 20 mul of the extract. The detection limit of the HPLC method was 0.5 mug/ml ergosterol, equivalent to 0.06 mug/g in 25 g fresh soil. Changes in ergosterol contents of peaty soil treated with fungicide, and in samples of the peaty podzol and a humus iron podzol in the vicinity of fungal fruiting bodies, have been determined.
authors.affiliation: Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, U.K.
authors.forename: P
authors.initials: P
authors.lastname: Anderson
authors.forename: C M
authors.initials: CM
authors.lastname: Davidson
authors.forename: D
authors.initials: D
authors.lastname: Littlejohn
authors.forename: A M
authors.initials: AM
authors.lastname: Ure
authors.forename: C A
authors.initials: CA
authors.lastname: Shand
authors.forename: M V
authors.initials: MV
authors.lastname: Cheshire