Analysis of heterocyclic amines in food products: interlaboratory studies

A feasibility study and two interlaboratory exercises on the determination of selected heterocyclic amines (HAs) in beef extract, organised in the framework of a European project, are presented. The aim of these exercises was to improve the quality of the laboratories and to evaluate the performance of a standardised analytical method and also the methods currently used by each of the participants for the analysis of these compounds. Three lyophilised portions of a commercial beef material previously spiked with HAs at different concentration levels ranging from 10 to 75 ng g−1 were used as laboratory reference materials (lot A, B and C). Firstly, a feasibility study was carried out using a test standard solution and the beef extract (lot A), which contained only five HAs. Then, two interlaboratory exercises were carried out using the laboratory reference materials lot B and lot C, containing 10 selected HAs at two different concentration levels, 75 and 10 ng/g, respectively. The results obtained by all participant laboratories using the proposed method showed satisfactory agreement and the CV(%) between-laboratories obtained were from 8.3 to 24.1% for lot B and from 8.7 to 44.5% for lot C. The standardised method evaluated in these collaborative studies is therefore proposed for the analysis of HAs in food material. Moreover, LC–MS is recommended as the most suitable technique for the analysis of a large number of HAs in food samples.