Development and single laboratory validation of a method for citrinin

Abstract

Citrinin (CIT) is a nephrotoxic secondary metabolite produced by several fungal species. CIT contamination has been reported in many cereals. Recently CIT contamination of red mold rice, used as an artificial colour, received attention because a CIT producing Monascus species was used in its production. Therefore, we developed a relatively simple method, immunoaffinity column clean-up followed by high performance liquid chromatographic (IAC-HPLC) detection, to determine CIT in red mold rice and several other commodities, and performed a single laboratory validation of the method. CIT was extracted by shaking for 30 min with 70% methanol, after which the extract was purified using an immunoaffinity column. The isolated CIT was quantitated by HPLC with fluorescence detection. Recoveries of CIT from red mold rice and koji-rice at levels of 50-2,500 µg/kg were 81-88%. RSDs, estimated with naturally contaminated red mold rice at 50, 200 and 400 µg/kg were 5.1%, 2.8% and 4.1%, respectively. Recoveries of CIT from cereals and mushroom samples at 50, 200 and 400 µg/kg were 60-123%, 69-88% and 73-100% with RSDs of 2.1-7.8%, 1.7-9.2% and 0.6-5.3%, respectively.