title: Development and validation of an analytical method for the determination of semicarbazide in fresh egg and in egg powder based on the use of liquid chromatography tandem mass spectrometry.
abstract: In this work the development of a method to determine semicarbazide (SEM) in fresh whole egg and in whole egg and egg white powders as those used in the food industry, by using LC-MS/MS is described. The method is based on a recently validated one for the determination of SEM in baby food. SEM is extracted from egg with 0.2 mol L(-1) hydrochloric acid and derivatised with 2-nitrobenzaldehyde. The extract is neutralised and purified by passing through a solid phase extraction (SPE) cartridge. The 2-nitrobenzaldehyde derivative is eluted with ethyl acetate. The eluate is evaporated to dryness and the residue re-dissolved in methanol:water mobile phase. SEM is determined by reversed-phase LC-MS/MS. The "in-house" validation of this method has been performed taking into account the "Harmonized guidelines for single-laboratory validation of methods of analysis" (IUPAC Technical report) and the Commission Decision (2002/657/EC). The performance characteristics of the method were established by in-house validation procedures employing assays with standard solutions, sample blanks and spiked samples. Linearity, matrix effect, trueness, precision, selectivity, limits of detection and of quantification were determined. The fitness for purpose of this method was assessed based on its performance characteristics. LOD's of 0.15 and 0.4 microg kg(-1) for whole fresh egg and industrial egg powders, respectively, were obtained. The LOQ for fresh whole egg was 0.2 microg kg(-1) and for industrial egg powders 0.8 microg kg(-1). Linear calibration curves were obtained in the ranges 1-100 and 0.8-400 microg kg(-1) for fresh whole egg and the egg powders, respectively.
authors.affiliation: European Commission, Directorate General Joint Research Centre, Institute for Reference Materials and Measurements, Retieseweg 111, 2440 Geel, Belgium.
authors.forename: Szilard
authors.initials: S
authors.lastname: Szilagyi
authors.forename: Beatriz
authors.initials: B
authors.lastname: de la Calle