Determination of ergosterol on mouldy building materials using isotope dilution and gas chromatography-tandem mass spectrometry

Ergosterol content of building materials was quantified using gas chromatography-tandem mass spectrometry (GC-MS-MS) in an ion trap with external ionisation. Hydrolysing the samples by classic extraction at 85 degreesC for 90 min in vials was faster, more precise and safer than microwave assisted extraction. [4-(2)H(2)]ergosterol was synthesised and used as internal standard, giving method standard deviation of 5-10% from 10 to 30 ng to 10-15 mug ergosterol in the sample. The use of GC-MS-MS meant that no solid-phase extraction clean-up was needed, so one person could easily prepare 40-80 samples per day. (C) 2000 Elsevier Science BN. All rights reserved.