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A rapid, simple and sensitive method based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) with an electrospray ionization (ESI) source for the simultaneous analysis of fourteen water-soluble vitamins (B1, B2, two B3 vitamers, B5, five B6 vitamers, B8, B9, B12 and C) in various food matrices, i.e. maize flour, green and golden kiwi and tomato pulp, is presented here. Analytes were separated by ion-suppression reversed-phase liquid chromatography in less than 10 min and detected in positive ion mode. Sensitivity and specificity of this method allowed two important results to be achieved: (i) limits of detection of the analytes at ng g(-1) levels (except for vitamin C); (ii) development of a rapid sample treatment that minimizes analyte exposition to light, air and heat, eliminating any step of extract concentration. Analyte recovery depended on the type of matrix. In particular, recovery of the analytes in maize flour was > or =70%, with the exception of vitamin C, pyridoxal-5'-phosphate and vitamin B9 (ca 40%); with tomato pulp, recovery was > or =64%, except for vitamin C (41%); with kiwi, recovery was > or =73%, except for nicotinamide (ca. 30%).

Within the European Union the use of anabolic steroids for promoting growth and improving meat-to-fat ratio in food-producing animals has been banned since 1988. For the unequivocal identification of hormone residues in a complex matrix such as meat we have developed a rapid, specific and sensitive liquid chromatography/tandem mass spectrometry (LC/MS/MS) method, in combination with a simple extraction procedure based on the matrix solid-phase dispersion (MSPD). The performances of a triple quadrupole (QqQ) and a quadrupole/time-of-flight (QqTOF) were compared: the QqQ mass spectrometer was found to be more sensitive for almost all studied analytes, but the selectivity was superior using the QqTOF system; the full-scan spectra (acquired without losing sensitivity), mass accuracy and resolution of the hybrid instrument enabled a more probatory analyte identification than that obtained selecting two multiple-reaction monitoring (MRM) transitions with a QqQ. Average recoveries ranged from 80 to 100%, and the detection capabilities (CCbetas) were less than 1.06 ppb with the QqQ instrument and less than 5.20 ppb with the QqTOF instrument for the bovine meat, which proved to be the most complex matrix., (Copyright (c) 2006 John Wiley & Sons, Ltd.)

A simple and rapid method using reversed-phase liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the simultaneous determination of the urinary metabolites of benzene, toluene, xylene and styrene in human urine specimens and standard solutions is described. A hybrid quadrupole/time-of-flight (QqTOF) mass spectrometer was compared for the determination of metabolite of aromatic solvents in urine samples. The metabolites selected were: trans,trans-muconic acid, hippuric acid, o-, m- and p-methylhippuric acid and phenylglyoxylic acid. The compounds were well separated from each other on narrow-bore 1-mm i.d. reversed-phase LC C-18 columns. Average recoveries for loading 100 microL of urine samples varied from 88-110% and the quantification limits were less than 30 ng/mL for each analyte (3 ng/mL for trans,trans-muconic acid). The qualitative information obtained (mass accuracy, resolution and full-scan spectra) with the QqTOF mass spectrometer allows a secure identification of analytes in biological matrices., (Copyright 2004 John Wiley & Sons, Ltd.)

This paper describes a rapid extraction method, based on a matrix solid-phase dispersion technique using diatomaceous earth as solid support and 50:50 (v/v) chloroform/methanol as extracting solvent, that can determine 11 free fatty acids in chocolate. The extraction procedure is followed by reversed-phase liquid chromatography/tandem mass spectrometry (LC/MS/MS) using a normal-bore (4.6 mm i.d.) C-18 column and an electrospray interface operating in the negative ion mode. The tandem mass spectra of selected compounds show that charge-remote fragmentation (CRF) mechanisms are occurring; the intensities of the CRF reactions increase with the carbon number and degree of unsaturation of the fatty acids. Average recoveries, evaluated by the standard addition method, vary between 79-103%, and the estimated quantification limits are less than 153 ng/g. The proposed method has been used to analyse nine chocolate samples from various price ranges, bought from supermarkets., (Copyright 2004 John Wiley & Sons, Ltd.)

A triple-quadrupole instrument and a hybrid quadrupole/time-of-flight (TOF) mass spectrometer were compared for the determination of pharmaceutical compounds in water samples. The drugs investigated were the analgesics Ibuprofen, Fenoprofen, Ketoprofen, Naproxen, and Diclofenac. The recently introduced Q2-pulsing function, which enhances the transmission of fragment ions of a selected m/z window from the collision cell into the TOF analyzer, improved the sensitivity of product ion scans on the quadrupole/TOF instrument. The selectivity is much better on quadrupole/TOF systems than on triple quadrupoles because the high resolving power of the reflectron-TOF mass analyzer permits high-accuracy fragment ion selection. This minimizes interferences from environmental matrices and allows acquisition of full spectra for selected analytes with better signal-to-noise characteristics than comparable spectra obtained with a scanned quadrupole. The qualitative information obtained (mass accuracy, resolution and full-scan spectra) by hybrid quadrupole/TOF mass spectrometry allows a more certain identification of analytes in environmental matrices at trace levels. Sample enrichment of water samples was achieved by a solid-phase extraction procedure. Average recoveries for loading 1 L of samples varied from 88 to 110%, and the quantification limits were less than 1.2 ng/L for the triple-quadrupole instrument (in MRM mode) and less than 3 ng/L for the quadrupole/TOF instrument., (Copyright 2003 John Wiley & Sons, Ltd.)

An evaluation was made of the feasibility of using reversed-phase liquid chromatography/tandem mass spectrometry with an electrospray interface (LC/ESI-MS/MS) to measure traces of phenoxyacid herbicides and their metabolites in surface and drinking water samples. The procedure involved passing 0.5 L of river and drinking water samples through a 0.5 g graphitized carbon black (GCB) extraction cartridge. Recovery was higher than 85% irrespective of the aqueous matrix in which the analytes were dissolved. A conventional 4.6-mm i.d. reversed-phase LC C-18 column operating with a mobile phase flow rate of 1 mL/min was used to chromatograph the analytes. A flow of 200 microL/min of the column effluent was diverted to the ESI source. The limits of detection (signal-to-noise ratio = 3) of the method for the pesticides considered in drinking and surface water samples are less than 0.1 ng/L for phenoxyacid herbicides, and about 5-10 ng/L for their metabolites (2,4-dichlorophenol and 4-chloro-2-methylphenol)., (Copyright 2001 John Wiley & Sons, Ltd.)

A sensitive and specific analytical procedure for determining arylphenoxypropionic herbicides in soil samples, using Ionspray ionization (ISI) liquid chromatography/mass spectrometry (LC/MS), is presented. Arylphenoxypropionic acids are a new class of herbicides used for selective removal of most grass species from any non-grass crop, commercialized as herbicide esters. Previous studies have shown that the esters undergo fast hydrolysis in the presence of vegetable tissues and soil bacteria, yelding the corresponding free acid. The feasibility of rapidly extracting arylphenoxypropionic herbicides from soil by accelerated solvent extraction (ASE) techniques was evaluated. Four different soil samples were fortified with target compounds at levels of 5 and 20 ng/g by following a procedure able to mimic weathered soils. Herbicides were extracted by a methanol/water (80:20 v/v) solution (0.12 M) of NaCl at 90 degrees C. After clean-up using graphitized carbon black (GCB) as absorbent, the extract was analyzed by HPLC/ISI-MS. The effect of concentration of acid in the mobile phase on the response of ISI-MS was investigated. The effects of varying the orifice plate voltage on the production of diagnostic fragment ions, and on the response of the MS detector, were also investigated. The ISI-MS response was linearly related to the amounts of analytes injected between 1 and 200 ng. The limit of detection (signal-to-noise ratio = 3) of the method for the pesticides in soil samples was estimated to be less than 1 ng/g.