title: Feasibility study for producing a carrot/potato matrix reference material for 11 selected pesticides at EU MRL level: material processing, homogeneity and stability assessment.
abstract: The feasibility for producing a matrix reference material for selected pesticides in a carrot/potato matrix was investigated. A commercially available baby food (carrot/potato-based mash) was spiked with 11 pesticides at the respective EU maximum residue limits (MRLs), and further processed by either freezing or freeze-drying. Batches of some 150 units were produced per material type. First, the materials were assessed for the relative amount of pesticide recovered after processing (ratio of pesticide concentration in the processed material to the initially spiked pesticide concentration). In addition, the materials' homogeneity (bottle-to-bottle variation), and the short-term (1 month) and mid-term (5 months) stability at different temperatures were assessed. For this, an in-house validated GC-EI-MS method operated in the SIM mode with a sample preparation procedure based on the QuEChERS ("quick, easy, cheap, effective, rugged, and safe") principle was applied. Measurements on the frozen material provided the most promising results (smallest analyte losses during production), and also freeze-drying proved to be a suitable alternative processing technique for most of the investigated pesticides. Both the frozen and the freeze-dried material showed to be sufficiently homogeneous for the intended use, and storage at -20°C for 5 months did not reveal any detectable material degradation. The results constitute an important step towards the development of a pesticide matrix reference material.
authors.affiliation: European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, 2440 Geel, Belgium.
authors.forename: Helena
authors.initials: H
authors.lastname: Saldanha
authors.affiliation: European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, 2440 Geel, Belgium.
authors.forename: Berit
authors.initials: B
authors.lastname: Sejerøe-Olsen
authors.affiliation: European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, 2440 Geel, Belgium.
authors.forename: Franz
authors.initials: F
authors.lastname: Ulberth
authors.affiliation: European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, 2440 Geel, Belgium.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Emons
authors.affiliation: European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, 2440 Geel, Belgium. Electronic address: reinhard.zeleny@ec.europa.eu.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Zeleny
mesh_terms: D018552:Daucus carota / Q000737:chemistry*; D005240:Feasibility Studies; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D010575:Pesticides / Q000032:analysis / Q000737:chemistry*; D011198:Solanum tuberosum / Q000737:chemistry*
chemical_list: D010575:Pesticides
keywords: Feasibility study; Food; GC–MS; Homogeneity; Matrix reference material; Pesticides; Processing; Stability