Analysis of ergosterol for the detection of mold in soils by automated on-fiber derivatization headspace extraction–SPME-GC/MS

The estimate of ergosterol ([5,7,22-ergostatrien-3β-ol] has been used by many to relate its concentration to the amount of mold in soils. This new method using on-fiber derivatization–solid phase microextraction-GC/MS method for the analysis of ergosterol presents a quick and straightforward method where low detection limits (1.5 ppb) and good limit of quantitation range (3 ppb to 90 ppm) can be achieved with careful control of analytical parameters. After saponification of real soil samples, sampling without extensive workup can be performed and analysis by a standard addition method can be utilized to deduce the original sample concentration of ergosterol. Peak area extraction analysis by MS SIM on selected characteristic fragment ions gives results with RSD ≤ 2.2%.