TY - JOUR T1 - Accurate determination of 3-alkyl-2-methoxypyrazines in wines by gas chromatography quadrupole time-of-flight tandem mass spectrometry following solid-phase extraction and dispersive liquid-liquid microextraction. AU - Fontana,Ariel, AU - Rodríguez,Isaac, AU - Cela,Rafael, Y1 - 2017/07/29/ PY - 2017/05/22/received PY - 2017/07/26/revised PY - 2017/07/27/accepted PY - 2017/8/6/pubmed PY - 2017/10/13/medline PY - 2017/8/6/entrez KW - Dispersive liquid–liquid microextraction KW - Gas chromatography time-of-flight mass spectrometry KW - Methoxypyrazines KW - Solid-phase extraction KW - Wine analysis SP - 30 EP - 36 JF - Journal of chromatography. A JO - J Chromatogr A VL - 1515 N2 - A new reliable method for the determination 3-alkyl-2-methoxypyrazines (MPs) in wine samples based on the sequential combination of solid-phase extraction (SPE), dispersive liquid-liquid microextraction (DLLME) and gas chromatography (GC) quadrupole time-of-flight accurate tandem mass spectrometry (QTOF-MS/MS) is presented. Primary extraction of target analytes was carried out by using a reversed-phase Oasis HLB (200mg) SPE cartridge combined with acetonitrile as elution solvent. Afterwards, the SPE extract was submitted to DLLME concentration using 0.06mL carbon tetrachloride (CCl4) as extractant. Under final working conditions, sample concentration factors above 379 times and limits of quantification (LOQs) between 0.3 and 2.1ngL-1 were achieved. Moreover, the overall extraction efficiency of the method was unaffected by the particular characteristics of each wine; thus, accurate results (relative recoveries from 84 to 108% for samples spiked at concentrations from 5 to 25ngL-1) were obtained using matrix-matched standards, without using standard additions over every sample. Highly selective chromatographic records were achieved considering a mass window of 5mDa, centered in the quantification product ion corresponding to each compound. Twelve commercial wines, elaborated with grapes from different varieties and geographical origins, were processed with the optimized method. The 2-isobutyl-3-methoxypyrazine (IBMP) was determined at levels above the LOQs of the method in half of the samples. SN - 1873-3778 UR - https://www.unboundmedicine.com/medline/citation/28778530/Accurate_determination_of_3_alkyl_2_methoxypyrazines_in_wines_by_gas_chromatography_quadrupole_time_of_flight_tandem_mass_spectrometry_following_solid_phase_extraction_and_dispersive_liquid_liquid_microextraction_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0021-9673(17)31129-9 DB - PRIME DP - Unbound Medicine ER -