title: Preparation of a calibrant as certified reference material for determination of the Fusarium mycotoxin zearalenone.
abstract: In the field of mycotoxin analysis, substantial problems shown by high between-laboratory standard deviations and noncomparable and nontraceable results have been caused by the lack of proper calibrants for external calibration. During a large-scale Standard Measurement and Testing project of the European Commission (EC) dealing with preparation and certification of reference materials for determination of the mycotoxin zearalenone (ZON) in maize, a ZON calibrant in acetonitrile was prepared and checked for purity, homogeneity, and stability. Before certification, on the basis of preparation, the calibrant was checked in a mini-interlaboratory study by UV spectrophotometric determination. The molar absorptivities of ZON in acetonitrile at 236, 274, and 314 nm were established, and as a main result, a common reference wavelength of 274 nm with molar absorptivity of 12623 +/- 111 L/mol x cm can be recommended for ZON in acetonitrile. A concentration and expanded uncertainty of the ZON calibrant of 9.95 +/- 0.08 microg/mL was calculated as a preliminary value before final evaluation through the certification panel of the EC.
authors.affiliation: Institute for Agrobiotechnology (IFA-Tulln), Center for Analytical Chemistry, Konrad Lorenz Strasse 20, A 3430 Tulln, Austria.
authors.forename: Ralf D
authors.initials: RD
authors.lastname: Josephs
authors.forename: Rudolf
authors.initials: R
authors.lastname: Krska
authors.forename: Susan
authors.initials: S
authors.lastname: MacDonald
authors.forename: Pete
authors.initials: P
authors.lastname: Wilson
authors.forename: Hans
authors.initials: H
authors.lastname: Pettersson
mesh_terms: D000097:Acetonitriles; D002138:Calibration; D004355:Drug Stability; D008433:Mathematics; D011786:Quality Control; D012015:Reference Standards; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D003313:Zea mays / Q000737:chemistry; D015025:Zearalenone / Q000032:analysis*
chemical_list: D000097:Acetonitriles; D012996:Solutions; D015025:Zearalenone; C032159:acetonitrile