Quantification of folpet and phthalimide in food by gas chromatography and mass spectrometry: Overcoming potential analytical artefacts. (15th September 2018)

• Record Type: Journal Article
• Authors: Huertas-Pérez, José Fernando; Ernest, Marion; Varela, Jesús; Badoud, Flavia
• Is Part Of: Food chemistry. Volume 260(2018)
• Page Start: 213
• Page End: 220
• Publication Date: 2018-09-15
• Subjects: Folpet -- Phthalimide -- Modified QuEChERS -- Gas chromatography -- Mass spectrometry -- Negative chemical ionization; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2018.04.002
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: GC-NCI-MS and GC-EI-MS/MS were compared for folpet and phthalimide quantification. GC-EI-MS/MS was appropriate for routine analysis. Optimized QuEChERS minimized folpet degradation and phthalimide contamination. Each matrix trigger folpet breakdown differently throughout the analytical process. Abstract: Accurate quantification of folpet is problematic because it degrades into phthalimide during sample preparation and analysis by gas chromatography (GC). Thus, EU regulation was recently modified to include phthalimide in the folpet residue definition. However, recent studies have shown that phthalimide could also be generated from different sources, which could lead to an overestimation of the phthalimide content and therefore to false positives. GC coupled with either negative chemical ionisation and single quadrupole mass spectrometry, or electron ionisation with triple quadrupole mass spectrometry (GC-EI-MS/MS), were evaluated for the determination of folpet and phthalimide in food. Both methods were validated in 4 different matrices namely apple puree, rice flour, raspberry puree and infant formula. Better selectivity and precision were obtained with GC-EI-MS/MS. Negligible amounts of phthalimide was found in blank matrices, and validation results met the SANTE/11813/2017 criteria in all matrices at the LOQ concentration levels by using GC-EI-MS/MS.