Single-laboratory validation of a method for ergosterol determination in cereals

Abstract

Ergosterol (ERG) is a sterol produced by most fungi, but not by most plants. Thus, measurement of ERG in cereals makes it possible to determine the presence of fungi in cereals that can cause quality problems, such as mycotoxin contamination. This study developed and performed a single-laboratory validation for a method to test for ERG in various cereals. ERG was extracted by refluxing samples for 1 h with methanol-sodium hydroxide. ERG was extracted from the extract with hexane and then purified using a silica gel cartridge column. ERG was then separated and detected by reverse-phase high-performance liquid chromatography (HPLC). ‘Within-day’ recoveries of ERG at low levels were 92–99% with relative standard deviations (RSDs) of 3.2–6.5%. ‘Between-day’ recoveries of ERG at low levels were 97% and RSDs were 4.2–10.2%, respectively. Average recoveries of ERG over the range from 1.0 to 100.0 mg kg⁻¹ were 81–105% and RSDs were 3.9–16.3%.

Keywords:

• ergosterol
• cereals
• mycotoxin
• method validation
• liquid chromatography

Acknowledgements

The authors thank Dr Chris Maragos for his suggestions during the preparation of this manuscript. This research was supported by a Development of evaluation and management methods for supply of safe, reliable and functional food and farm produce from the Ministry of Agriculture, Forestry and Fisheries of Japan.