Krska Rudolf, Welzig Elvira, Drs Elisabeth, Josephs Ralf D, Schothorst Ronald C, Van Egmond Hans P, Pettersson Hans, Chan Danny, MacDonald Susan
University of Natural Resources and Applied Life Sciences, Center for Analytical Chemistry, Department for Agrobiotechnology, IFA-Tulln, Vienna, Konrad Lorenz Strasse 20, A-3430 Tulln, Austria.
J AOAC Int. 2006 Nov-Dec;89(6):1573-80.
Thirteen European laboratories experienced in the analysis of mycotoxins participated in an intercomparison study within a European Commission-funded project. Goals of the study were to check the fitness for purpose of a small batch of gravimetrically prepared calibrants; to compare individually prepared calibrants with common calibrants; to check the feasibility of toxin mixtures as calibrant solutions; and to give recommendations on the production of future certified reference materials (CRMs) with regard to the nature of the calibrant and the means of certification. Each laboratory received ampules of each common calibrant containing single toxins [solution containing either deoxynivalenol (DON), 3-acetyl-DON (3-Ac-DON), nivalenol (NIV), or 15-acetyl-DON (15-Ac-DON)] and 3 ampules of toxin-mixture (solutions of DON + 3-Ac-DON + NIV in acetonitrile) of known concentrations (about 20 microg/mL). Ampules with single toxins (solution containing either DON, 3-Ac-DON, NIV, or 15-Ac-DON) and a toxin-mixture (solutions of DON + 3-Ac-DON + NIV in acetonitrile) of unknown concentrations were distributed to the participants for quantification. The participating laboratories used mainly high-performance liquid chromatography (HPLC)-diode array detection UV for DON, 3-Ac-DON, NIV, and 15-Ac-DON; gas chromatography-electron capture detection (GC-ECD) and GC-mass spectrometry methods were used sparingly. Linear calibration curves were achieved by >90% of the participants. Relative between-day variation (RSDr) of 26% of the laboratories was greater than the target value of 5% for HPLC, and RSDr of 32% of the laboratories was greater than the desired value of 10% for GC. Relative between-laboratory variation (RSDR) of the GC results obtained with single common calibrants was greater than the target value of 16% for all laboratories. RSDR of the HPLC results for the common unknown single toxin solutions was less than the target value of 8% except for 15-Ac-DON. Generally, better recoveries were observed from common calibrants (102% for mix calibrants and 98% for single calibrants) than from individually prepared calibrants (95%). This international comparison study clearly showed the high scattering of results in the analysis of type-B trichothecenes, particularly when GC was used. Obviously, this intercomparison study was not suited for the certification of B-trichothecenes. A certification of the proposed calibrant material was therefore recommended on the basis of its gravimetrical preparation.
13个在霉菌毒素分析方面经验丰富的欧洲实验室参与了欧盟委员会资助项目中的一项比对研究。该研究的目标是检查一小批重量法制备的校准物是否适用于目标；将单独制备的校准物与通用校准物进行比较；检查毒素混合物作为校准溶液的可行性；并就未来有证标准物质（CRM）的生产，在校准物的性质和认证方法方面给出建议。每个实验室收到了每种含有单一毒素的通用校准物的安瓿（含有脱氧雪腐镰刀菌烯醇（DON）、3-乙酰-DON（3-Ac-DON）、雪腐镰刀菌烯醇（NIV）或15-乙酰-DON（15-Ac-DON）的溶液）以及3个已知浓度（约20微克/毫升）的毒素混合物（DON + 3-Ac-DON + NIV的乙腈溶液）的安瓿。将含有单一毒素（含有DON、3-Ac-DON、NIV或15-Ac-DON的溶液）和未知浓度的毒素混合物（DON + 3-Ac-DON + NIV的乙腈溶液）的安瓿分发给参与者进行定量分析。参与实验室主要使用高效液相色谱（HPLC）-二极管阵列检测紫外法分析DON、3-Ac-DON、NIV和15-Ac-DON；气相色谱-电子捕获检测（GC-ECD）和气相色谱-质谱法使用较少。超过90%的参与者获得了线性校准曲线。26%的实验室HPLC的日间相对变化（RSDr）大于目标值5%，32%的实验室GC的RSDr大于预期值10%。对于所有实验室，使用单一通用校准物获得的GC结果的实验室间相对变化（RSDR）大于目标值16%。除15-Ac-DON外，通用未知单一毒素溶液的HPLC结果的RSDR小于目标值8%。一般来说，通用校准物（混合校准物为102%，单一校准物为98%）的回收率比单独制备的校准物（95%）更好。这项国际比对研究清楚地表明，在B型单端孢霉烯族毒素分析中结果的离散度很高，尤其是使用GC时。显然，这项比对研究不适用于B型单端孢霉烯族毒素的认证。因此，建议根据其重量法制备对提议的校准物材料进行认证。
