RESUMO
An analytical method was developed to determine the phenoxyacid herbicides 2,4-D, MCPA and mecoprop in kidney tissue from animals where poisoning is suspected. Samples were Soxhlet extracted using diethyl ether and the extracts cleaned-up using anion exchange solid phase extraction cartridges. Analysis was performed using liquid chromatography with negative-ion electrospray tandem mass spectrometry (LC-MS/MS). The method was evaluated by analysing control kidney samples fortified at 1 and 5 mg/kg. Mean recoveries ranged from 82 to 93% with relative standard deviations from 3.2 to 19%. The limit of detection was estimated to be 0.02 mg/kg.
Assuntos
Ácido 2,4-Diclorofenoxiacético/análise , Ácido 2-Metil-4-clorofenoxiacético/análogos & derivados , Ácido 2-Metil-4-clorofenoxiacético/análise , Cromatografia Líquida/métodos , Rim/química , Extração em Fase Sólida/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Ácido 2,4-Diclorofenoxiacético/isolamento & purificação , Ácido 2,4-Diclorofenoxiacético/intoxicação , Ácido 2-Metil-4-clorofenoxiacético/isolamento & purificação , Ácido 2-Metil-4-clorofenoxiacético/intoxicação , Animais , Suínos , Espectrometria de Massas em TandemRESUMO
We report the development of a qualitative method to detect the addition of blood-based binding agents to food products. The method is based on the detection of species-specific marker peptides, fibrinopeptides, released from the blood protein fibrinogen during gelling of the blood protein by thrombin. The fibrinopeptides were isolated from foods spiked with commercial bovine binding agent by acid precipitation followed by enrichment using solid-phase extraction and analysed by liquid chromatography electrospray ionisation triple quadrupole mass spectrometry. Fibrinopeptide A was found to be an effective marker in fresh, processed and cooked food matrices spiked with 5% (v/w) bovine binding agent.
Assuntos
Análise Química do Sangue/métodos , Cromatografia Líquida de Alta Pressão/métodos , Fibrinogênio/análise , Aditivos Alimentares/análise , Análise de Alimentos/métodos , Carne/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Peixes , Contaminação de Alimentos/análise , Coloração e Rotulagem/métodos , SuínosRESUMO
A robust and sensitive method for the determination of ethylenethiourea (ETU) and iso-propylenethiourea (i-PTU) in foods is reported. ETU and i-PTU were extracted by blending with dichloromethane (DCM) in the presence of sodium sulphate, sodium carbonate, thiourea and ascorbic acid. 2H4-ETU and n-PTU were used as internal standards. After filtration the DCM was removed by rotary evaporation and the extract re-dissolved in water before analysis by reversed-phase liquid chromatography with detection by atmospheric pressure chemical ionization-mass spectrometry using a double focusing mass spectrometer at a resolution of 5000. Mean recoveries of ETU and i-PTU from fruit-based, cereal-based and meat-based infant foods, potato chips and tinned potatos at 0.01 mg kg(-1) and from pizza and yoghurt at 0.02-0.1 mg kg(-1) were 95% and 97% respectively. Precision, including both repeatability and internal reproducibility, was in the range of 3.1-13.1%.
Assuntos
Etilenotioureia/análise , Análise de Alimentos/métodos , Tioureia/análogos & derivados , Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Alimentos/análise , Manipulação de Alimentos , Fungicidas Industriais/análise , Espectrometria de Massas/métodos , Oxirredução , Reprodutibilidade dos Testes , Tioureia/análiseRESUMO
A multi-residue screening method was developed for the simultaneous analysis of 73 pesticides and their metabolites using high-performance liquid chromatography coupled with electrospray tandem mass spectrometry. These pesticides were determined under a single set of experimental conditions involving a simple acetonitrile extraction without the requirement for a clean-up step. Validation was achieved at 0.01 and 0.1 mg kg(-1) levels in apple, lettuce and orange. Recoveries were in the range 77-124% for the majority of pesticides.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Alimentos/análise , Frutas/metabolismo , Praguicidas/análise , Verduras/metabolismo , Frutas/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray , Verduras/químicaRESUMO
A method for determination of triforine using high-performance liquid chromatography with electrospray tandem mass spectrometry was developed. A simple ethyl acetate extraction with solvent exchange into water/methanol was used for sample preparation. The method was validated at 0.01 and 0.05 mg kg(-1) levels in apple, tomato and tinned blackcurrants. Recoveries were in the range 56.6-99.8% and no matrix suppression or enhancement effects were observed.
