title: High accuracy determination of malachite green and leucomalachite green in salmon tissue by exact matching isotope dilution mass spectrometry.
abstract: A high accuracy method for the quantification of malachite green (MG) and leucomalachite green (LMG) in salmon is described. Analytical challenges including the effects of analyte instability and matrix suppression were minimised by the use of exact matching isotope dilution mass spectrometry. The developed method included overnight extraction in acidified acetonitrile/ammonium acetate buffer and analysis by LC-MS/MS utilising isotopic internal standards. This method was used to determine the level of MG and LMG in a sample of salmon used in an international inter-comparison organised by the Comité Consultatif pour la Quantité de Matière (CCQM). The sum of MG and LMG was found to be 9.32+/-0.98ngg(-1) at the 95% confidence interval (relative expanded uncertainty 10.5% (k=2)). This encompassed the mean and median of the CCQM inter-comparison.
authors.affiliation: LGC, Mass Spectrometry, Queens Road, Teddington, Middlesex TW11 0LY, UK. zoe.hall@lgc.co.uk
authors.forename: Zoe
authors.initials: Z
authors.lastname: Hall
authors.forename: Chris
authors.initials: C
authors.lastname: Hopley
authors.forename: Gavin
authors.initials: G
authors.lastname: O'Connor
mesh_terms: D000818:Animals; D002138:Calibration; D002247:Carbon Isotopes / Q000737:chemistry; D002853:Chromatography, Liquid; D015394:Molecular Structure; D011865:Radioisotope Dilution Technique / Q000592:standards; D015203:Reproducibility of Results; D012394:Rosaniline Dyes / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D012474:Salmon / Q000378:metabolism*; D053719:Tandem Mass Spectrometry / Q000379:methods* / Q000592:standards
chemical_list: D002247:Carbon Isotopes; D012394:Rosaniline Dyes; C005095:malachite green; C015320:leucomalachite green