Quantitative determination of taurine and related biomarkers in urine by liquid chromatography–tandem mass spectrometry

Current urinary bladder cancer diagnosis is commonly based on a biopsy obtained during cystoscopy. This invasive method causes discomfort and pain in patients. Recently, taurine and several other compounds such as L-phenylalanine and hippuric acid in urine were found to be indicators of bladder cancer. However, because of a lack of sensitive and accurate analytical techniques, it is impossible to detect these compounds in urine at low levels. In this study, using liquid chromatography–tandem mass spectrometry (LC-MS/MS), a noninvasive method was developed to separate and detect these compounds in urine. ¹⁵N₂-L-glutamine was used as the internal standard, and creatinine acted as an indicator for urine dilution. A phenyl-hexyl column was used for the separation at an isocratic condition of 0.2% formic acid in water and 0.2% formic acid in methanol. Analytes were detected in multiple-reaction monitoring with positive ionization mode. The limit of detection range is 0.18–6 nM and the limit of quantitation ranges from 0.6 to 17.6 nM. The parameters affecting separation and quantification were also investigated and optimized. Proper clinical validation of these biomarkers can be done using this reliable, fast, and simple method. Furthermore, with simple modifications, this method could be applied to other physiological fluids and other types of diseases.     

Group-specific fragmentation of pesticides and related compounds in liquid chromatography–tandem mass spectrometry

Current strategies in the LC–MS analysis of pesticides and related compounds in environmental samples, fruits and vegetables, and biological samples mostly rely on the selection of appropriate precursor/product-ion combinations (transitions) for selected reaction monitoring (SRM), often based on automated parameter optimization and selection of the transition. Such a procedure does not require any information on the type of fragmentation reaction involved in the generation of the product ion from the selected precursor ion. However, such information does become important in untargeted screening for unknown contaminants in environmental and food samples, which are generally based on a combination of high-resolution mass spectrometry and (multistage) tandem mass spectrometry. With this in mind, the group-specific fragmentation behaviour has been studied for six classes of pesticides and herbicides, i.e., triazines, organophosphorous pesticides, phenylurea herbicides, carbamates, sulfonylurea herbicides, and chlorinated phenoxy acid herbicides. When relevant, some comparison was made between fragmentation of protonated molecules in MS–MS and of molecular ions generated by electron ionization in GC–MS.     

Pre-concentration of phenolic compounds in water samples by novel liquid–liquid microextraction and determination by gas chromatography–mass spectrometry

Pre-concentration and determination of 8 phenolic compounds in water samples has been achieved by in situ derivatization and using a new liquid–liquid microextraction coupled GC–MS system. Microextraction efficiency factors have been investigated and optimized: 9 μL 1-undecanol microdrop exposed for 15 min floated on surface of a 10 mL water sample at 55 °C, stirred at 1200 rpm, low pH level and saturated salt conditions. Chromatographic problems associated with free phenols have been overcome by simultaneous in situ derivatization utilizing 40 μL of acetic anhydride and 0.5% (w/v) K₂CO₃. Under the selected conditions, pre-concentration factor of 235–1174, limit of detection of 0.005–0.68 μg/L (S/N = 3) and linearity range of 0.02–300 μg/L have been obtained. A reasonable repeatability (RSD ≤ 10.4%, n = 5) with satisfactory linearity (0.9995 ≥ r² ≥ 0.9975) of results illustrated a good performance of the present method. The relative recovery of different natural water samples was higher than 84%.     

Simultaneous determination of NOGE-related and BADGE-related compounds in canned food by ultra-performance liquid chromatography–tandem mass spectrometry

An improved analytical method enabling rapid and accurate determination and identification of bisphenol F diglycidyl ether (novolac glycidyl ether 2-ring), novolac glycidyl ether 3-ring, novolac glycidyl ether 4-ring, novolac glycidyl ether 5-ring, novolac glycidyl ether 6-ring, bisphenol A diglycidyl ether, bisphenol A (2,3-dihydroxypropyl) glycidyl ether, bisphenol A (3-chloro-2-hydroxypropyl) glycidyl ether, bisphenol A bis(3-chloro-2-hydroxypropyl) ether, and bisphenol A (3-chloro-2-hydroxypropyl) (2,3-dihydroxypropyl) ether in canned food and their contact packaging materials has been developed by using, for the first time, ultra-performance liquid chromatography coupled with tandem mass spectrometry. After comparison of electrospray ionization and atmospheric pressure chemical ionization in positive and negative-ion modes, tandem mass spectrometry with positive electrospray ionization was chosen to carry out selective multiple reaction monitoring analysis of novolac glycidyl ethers, bisphenol A diglycidyl ether, and its derivatives. The analysis time is only 5.5 min per run. Limits of detection varied from 0.01 to 0.20 ng g(-1) for the different target compounds on the basis of a signal-to-noise ratio (S/N) = 3; limits of quantitation were from 0.03 to 0.66 ng g(-1). The relative standard deviation for repeatability was <8.01%. Analytical recovery ranged from 87.60 to 108.93%. This method was successfully applied to twenty samples of canned food and their contact packaging materials for determination of migration of NOGE, BADGE, and their derivatives from can coatings into food.     

Residue analysis of glucocorticoids in bovine milk by liquid chromatography–tandem mass spectrometry

A sensitive liquid chromatography–tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of 13 steroidal anti-inflammatory drugs in bovine milk is presented. Due to their weakly acid nature, analytes were separated by ion suppression reversed phase chromatography and detected in positive-ion mode by a high flow electrospray source. Dexamethasone-d4 was used as internal standard. The sample preparation was simple and reliable; it included acidic deproteinization of milk followed by sample enrichment and clean-up, utilizing a C18 solid phase extraction cartridge. Recoveries exceeded 70% with an intra-day precision not larger than 12%. The efficiency of the sample clean-up and internal standardization rendered negligible the matrix effect, estimated by comparing standard and matrix-matched calibration curves. A small-scale reconnaissance was carried out on several raw and whole fresh milk samples. A large number of analyzed samples showed a chromatographic peak, in the retention time window of cortisol, at levels included between its decision limit (CCα) and detection capability (CCβ). As a result of a heat-induced transformation, an isomeric product of triamcinolone was observed during the extract evaporation. Since this rearrangement might occur during the milk pasteurization process, LC-MS/MS and ¹H-NMR investigations were performed out to conclusively differentiate the two isomers. One- and two-dimensional proton NMR spectra were able to identify the transformation product as 9a-fluoro-11b,16a-trihydroxy-17b-hydroxymethyl-D-homoandrosta-1,4-diene-3,17a-dione.     

Simultaneous quantification of multiple classes of phenolic compounds in blood plasma by liquid chromatography–electrospray tandem mass spectrometry

A method using high performance liquid chromatography–electrospray tandem mass spectrometry (LC–ESI-MS/MS) in positive ion mode was developed for the simultaneous analysis of 30 phenolic compounds, including four estrogens, bisphenol A (BPA), 10 hydroxylated polybrominated dephenyl ethers (OH-PBDEs) and 15 bromophenols (BRPs), in blood plasma. In the present method, derivatization with dansyl chloride was employed, and all the derivertized target compounds were well resolved on a 100 mm Xbridge C18 column with acetonitrile and 0.1% formic acid as the mobile phases. Purification procedures, such as liquid–liquid extraction and silica-gel chromatography, were applied to reduce matrix effects in the sample extract and remove excess derivatizing reagents, thus permitting selective and sensitive detection of the target phenolic compounds. The limit of quantification for all analytes, with a signal-to-noise ratio of ∼10, was 2–30 pg/g (plasma weight) except for 6-OH-BDE-137 (30 pg/g) and 3-BRP (60 pg/g). The method was validated for recoveries (68–100%), accuracy (84–110%) and precision (3.7–11%) using charcoal-stripped bovine blood plasma spiked with all target compounds (500 and 5000 pg/mL). Finally, the method was applied to analyze six blood plasma samples from frogs and cormorants, where two natural estrogens, one BPA, one OH-PBDE and four BRPs were detected. The greatest total concentrations of estrogens coincided with the least total concentrations of other phenolic compounds for both species. The proposed method based on derivatization followed by LC–MS/MS provides a novel method to simultaneously monitor multiple groups of phenolic compounds in blood plasma.     

The determination of β-agonist residues in bovine tissues using liquid chromatography–tandem mass spectrometry

We aimed to develop a rapid, simple and reproducible method based on LC–tandem mass spectrometry (LC–MS/MS) to analyze β-agonist residues (clenbuterol, zilpaterol, ractopamine and isoxsuprine) in bovine tissues. The method was validated in accordance with the European Council Decision 2002/657/EC. The samples were homogenized, and then 10 mL of an acetate buffer was added to a 5-g sample. The sample was then centrifuged at 12,000 rpm and filtered. Sodium hydroxide (2 m ) was added to adjust pH of the sample that was centrifuged again. The extract was filtered through a solid-phase extraction column. The residue was re-dissolved in 250 μL acetonitrile and then subjected to LC–MS/MS. The separation was done on a C₁₈ column. The mobile phase consisted of 0.1% formic acid in deionized water and 0.1% formic acid in methanol. The mean recoveries of β-agonists were in the range of 84.3%–119.1% with relative standard deviations (%RSDs) of 0.683%–4.05%. Decision limits and detection capabilities of the analytes ranged from 0.0960 to 4.9349 μg/kg and from 0.0983 to 5.0715, respectively. This method was used to detect four β-agonists in 100 bovine muscle, 100 liver and 100 kidney tissues from a slaughterhouse. No residue was found above the maximum residue limit level.     

Enantiomeric determination of azole antifungals in wastewater and sludge by liquid chromatography–tandem mass spectrometry

A sensitive and reliable liquid chromatographic-tandem mass spectrometric method for enantiomeric determination of five chiral azole antifungals (econazole, ketoconazole, miconazole, tebuconazole, and propiconazole) in wastewater and sludge has been established and validated. An isotope-labeled internal standard was used for quantification. Recovery of the individual enantiomers was usually in the range of 77-102 % for wastewater and 71-95 % for sludge, with relative standard deviations within 20 %. No significant difference (p>0.05) was observed between recovery of pairs of enantiomers of the chiral azole antifungals except for those of tebuconazole. Method quantification limits for individual enantiomers were 0.3-10 ng L(-1) and 3-29 ng g(-1) dry weight for wastewater and sludge, respectively. The method was used to investigate the enantiomeric composition of the azole pharmaceuticals in wastewater and sludge samples from a sewage treatment plant in China. Enantiomers of miconazole, ketoconazole, and econazole were widely detected. The results showed that the azole antifungals in wastewater and sludge were generally racemic or marginally non-racemic. The method is a useful tool for investigation of the enantiomeric occurrence, behavior, and fate of the chiral azole antifungals in the environment.     

Determination of perfluorinated compounds in mollusks by matrix solid-phase dispersion and liquid chromatography–tandem mass spectrometry

Perfluorinated compounds (PFCs) have been used for over 40 years in different commercial and industrial applications mainly as surfactants and surface protectors and have become an important class of marine emerging pollutants. This study presents the development and validation of a new analytical method to determine the simultaneous presence of eight PFCs in different kinds of mollusks using matrix solid-phase dispersion (MSPD) followed by liquid chromatography–tandem mass spectrometry (LC-MS/MS). Simplicity of the analytical procedure, low volume of solvent and quantity of sample required, low global price, and integration of extraction and clean-up into a single step, are the most important advantages of the developed methodology. Solvent, solid support (dispersing agent), clean-up sorbent, and their amounts were optimized by means of an experimental design. In the final method, 0.5 g of sample are dispersed with 0.2 g of diatomaceous earth and transferred into a polypropylene syringe containing 4 g of silica as clean-up sorbent. Then, analytes are eluted with 20 mL of acetonitrile. The extract is finally concentrated to a final volume of 0.5 mL in methanol, avoiding extract dryness in order to prevent evaporation losses and injected in the LC-MS/MS. The combination of this MSPD protocol with LC-MS/MS afforded detection limits from 0.05 to 0.3 ng g⁻¹. Also, a good linearity was established for the eight PFCs in the range from limit of quantification (LOQ) to 500 ng mL⁻¹ with R ² > 0.9917. The recovery of the method was studied with three types of spiked mollusk and was in the 64–126% range. Moreover, a mussel sample was spiked and aged for more than 1 month and analyzed by the developed method and a reference method, ion-pair extraction, for comparison, producing both methods statistically equal concentration values. The method was finally applied to the determination of PFCs in different kinds of mollusks revealing concentrations up to 8.3 ng g⁻¹ for perfluoroundecanoic acid.     

Trace determination of sulphur mustard and related compounds in water by headspace-trap gas chromatography–mass spectrometry

A method for trace determination of sulphur mustard (HD) and some of its cyclic decomposition compounds in water samples has been developed using headspace-trap in combination with gas chromatography–mass spectrometry (GC–MS). Factorial design was used for optimisation of the method. The trap technology allows enrichment and focusing of the analytes on an adsorbent, hence the technique offers better sensitivity compared to conventional static headspace. A detection limit of 1 ng/ml was achieved for HD, while the cyclic sulphur compounds 1,4-thioxane, 1,3-dithiolane and 1,4-dithiane could be detected at a level of 0.1 ng/ml. The method was validated for the stable cyclic compounds in the concentration range from the limit of quantification (LOQ: 0.2–0.4 ng/ml) to hundred times LOQ. The within and between assay precisions at hundred times LOQ were 1–2% and 7–8% relative standard deviation, respectively. This technique requires almost no sample handling, and the total time for sampling and analysis was less than 1 h. The method was successfully employed for muddy river water and sea water samples.     

Development and validation of a pressurized liquid extraction liquid chromatography–tandem mass spectrometry method for perfluorinated compounds determination in fish

This paper describes the development and validation of an analytical methodology to determine eight perfluorinated compounds (PFCs) in edible fish using pressurized liquid extraction (PLE) with water and solid-phase extraction (SPE) with an ion-exchanger as extraction and pre-concentration procedures, followed by liquid chromatography–quadrupole-linear ion trap mass spectrometry (LC–QqLIT–MS). The rapidity and effectiveness of the proposed extraction procedure were compared with those most commonly used to isolate PFCs from fish (ion-pairing and alkaline digestion). The average recoveries of the different fish samples, spiked with the eight PFCs at three levels (the LOQ, 10 and 100 μg kg⁻¹ of each PFC), were always higher than 85% with relative standard deviation (RSD) lower than 17%. A good linearity was established for the eight PFCs in the range from 0.003–0.05 to 100 μg kg⁻¹, with r > 0.9994. The limits of quantification (LOQs) were between 0.003 and 0.05 μg kg⁻¹, which are well below those previously reported for this type of samples. Compared with previous methods, sample preparation time and/or LOQs are reduced. The method demonstrated its successful application for the analysis of different parts of several fish species. Most of the samples tested positive, mainly for perfluoropentanoic acid (PFPA), perfluorobutane sulfonate (PFBS) and perfluorooctanoic acid (PFOA) but other of the eight studied PFCs were also present.     

Qualitative detection of desmopressin in plasma by liquid chromatography–tandem mass spectrometry

This work describes a liquid chromatography–electrospray tandem mass spectrometry method for detection of desmopressin in human plasma in the low femtomolar range. Desmopressin is a synthetic analogue of the antidiuretic hormone arginine vasopressin and it might be used by athletes as a masking agent in the framework of blood passport controls. Therefore, it was recently added by the World Anti-Doping Agency to the list of prohibited substances in sport as a masking agent. Mass spectrometry characterization of desmopressin was performed with a high-resolution Orbitrap-based mass spectrometer. Detection of the peptide in the biological matrix was achieved using a triple-quadrupole instrument with an electrospray ionization interface after protein precipitation, weak cation solid-phase extraction and high performance liquid chromatography separation with an octadecyl reverse-phase column. Identification of desmopressin was performed using three product ions, m/z 328.0, m/z 120.0, and m/z 214.0, from the parent ion, m/z 535.5. The extraction efficiency of the method at the limit of detection was estimated as 40% (n = 10), the ion suppression as 5% (n = 10), and the limit of detection was 50 pg/ml (signal-to-noise ratio greater than 3). The selectivity of the method was verified against several endogenous and synthetic desmopressin-related peptides. The performance and the applicability of the method were tested by analysis of clinical samples after administration of desmopressin via intravenous, oral, and intranasal routes. Only after intravenous administration could desmopressin be successfully detected.     

Quantitative determination of capsaicinoids by liquid chromatography–electrospray mass spectrometry

Eight naturally occurring capsaicinoids have been determined in Capsicum by use of high-purity standards, with norcapsaicin as an internal standard. The solid standards were rigorously checked for purity. The sensitivity of electrospray ionization (ESI), atmospheric-pressure chemical ionization (APCI), and coordination ion-spray (CIS; with silver) toward the capsaicinoids were measured and compared. The highest sensitivity was found for positive-ion ESI. Method validation of the liquid chromatography–ESI-mass spectrometry (LC–ESI-MS) determination is reported, including tests for repeatability (4%), detection limit (5 pg injected), linear range (20–6 ng injected), quantitation (excellent linearity; <2% relative standard deviation), and recovery (99–103%). The major and minor capsaicinoids in a commercial plant extract and in chili pepper fruits were quantified.Electronic Supplementary Material Supplementary material is available for this article at     

Analysis of nucleosides and nucleotides in infant formula by liquid chromatography–tandem mass spectrometry

A method for the simultaneous analysis of nucleosides and nucleotides in infant formula using reversed-phase liquid chromatography–tandem mass spectrometry is described. This approach is advantageous for compliance testing of infant formula over other LC-MS methods in which only nucleotides or nucleosides are measured. Following sample dissolution, protein was removed by centrifugal ultrafiltration. Chromatographic analyses were performed using a C₁₈ stationary phase and gradient elution of an ammonium acetate/bicarbonate buffer, mass spectrometric detection and quantitation by a stable isotope-labelled internal standard technique. A single laboratory validation was performed, with spike recoveries of 80.1–112.9 % and repeatability relative standard deviations of 1.9–7.2 %. Accuracy as bias was demonstrated against reference values for NIST1849a certified reference material. The method has been validated for the analysis of bovine milk-based, soy-based, caprine milk-based and hydrolysed milk protein-based infant formulae.

Determination of evodiamine and rutecarpine in human serum by liquid chromatography–tandem mass spectrometry

Evodiamine and rutecarpine are two kinds of indole alkaloids contained in the fruit of Evodiae fructus, which have been shown to exhibit various bioactivities in humans. A liquid chromatography–tandem mass spectrometric method (LC–MS/MS) was developed for the determination of evodiamine and rutecarpine in human serum. The serum was extracted by solid-phase extraction (SPE) and analyzed using a C18 column and a mobile phase consisting of methanol–water (85:15) solution containing 5 mmol/L ammonium formate at a flow rate of 0.5 mL/min. The mass spectrometer was operated in positive mode, employing the extracted ion chromatogram (EIC) for detection and quantitation of evodiamine (m/z 288) and rutecarpine (m/z 304). Good linear relationships between the peak area and the concentration were obtained in the ranges of 5.2–1040 ng/mL and 10.2–1020 ng/mL, with correlation coefficients (r) of 0.999 and 0.998, for evodiamine and rutecarpine, respectively. The repeatabilities (RSD, n=6) of quantitation for evodiamine and rutecarpine were 2.18–4.00% and 2.99–5.67%, respectively, and the recovery ranged from 90.5% to 98.1%. A comparative study of the different ionization and quantitation modes, including ESI–MS, ESI–MS/MS, APCI–MS and APCI–MS/MS, was also accomplished. The MS/MS fragmentation mechanism of the base peak ([M+H]⁺, m/z 304) of evodiamine was investigated in order to identify the analytes in more complicated body fluid samples.      

Development of a fast liquid chromatography–tandem mass spectrometry method for the determination of endocrine-disrupting compounds in waters

A fast liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS) method was developed to study five endocrine-disrupting compounds (4-n-nonylphenol, bisphenol A, estrone, 17β-estradiol and 17α-ethinylestradiol) in water. Different columns were tested; the chromatographic separation of the analytes was optimized on a Pinnacle DB biphenylic column with a water–acetonitrile gradient elution, which allowed the separation of the selected endocrine-disrupting compounds (EDCs) in less than 6 min. Quantitative analysis was performed in selected reaction monitoring (SRM) mode; two transitions were chosen for each compound, using the most abundant for quantitation. Calibration curves using bisphenol A-d ₁₆ as internal standard were drawn, showing good correlation coefficients (0.9993–0.9998). All figures of merit of the method were satisfactory; limits of detection were in the low pg range for all analytes. The method was then applied to the determination of the analytes in real water samples: to this aim, polar organic chemical integrative samplers (POCIS) were deployed in the influent and in the effluent of a drinking water treatment plant in Liguria (Italy). The EDC level was rather low in the influent and negligible in the outlet, reflecting the expected function of the treatment plant.     

Trace determination of nine haloacetic acids in drinking water by liquid chromatography–electrospray tandem mass spectrometry

A simple, fast and sensitive liquid chromatography–electrospray tandem mass spectrometry method was established for trace levels of nine haloacetic acids (HAAs) in drinking water. Water samples were removed of residual chlorine by adding l-ascorbic acid, and directly injected after filtered by 0.22 μm membrane. Nine HAAs were separated by liquid chromatography in 7.5 min, and the limits of detection were generally between 0.16 and 0.99 μg/L except for chlorodibromoacetic acid (1.44 μg/L) and tribromoacetic acid (8.87 μg/L). The mean recoveries of nine target compounds in spiked drinking water samples were 80.1–108%, and no apparent signal suppression was observed. Finally, this method was applied to determine HAAs in the tap water samples collected from five waterworks in Shandong, China. Nine HAAs except for monochloroacetic acid, monobromoacetic acid, dibromochloroacetic acid and tribromoacetic acid were detected, and the total concentrations were 7.79–36.5 μg/L. The determination results well met the first stage of the Disinfectants/Disinfection By-Products (D/DBP) Rules established by U.S.EPA and Guidelines for Drinking-water Quality of WHO.     

Determination of cyclopiazonic acid in food and feeds by liquid chromatography–tandem mass spectrometry

A new, fast and efficient multiple reaction monitoring (MRM) high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) method for the determination of cyclopiazonic acid (CPA) in mixed feed, wheat, peanuts and rice is presented. The analytical methodology involves sample extraction with an alkaline methanol–water mixture, defatting with hexane and quantification using HPLC–MS/MS without further treatment of sample extracts. Reversed-phase liquid chromatography using a C18 stationary phase coupled to negative mode electrospray triple quadrupole tandem mass spectrometry was applied. The limit of detection was 5 μg/kg while the limit of quantification was 20 μg/kg in the matrices investigated. The detector response was found to be linear over the range 25–250 μg/kg in feed and 25–500 μg/kg in wheat, peanuts and rice. The mean overall recoveries (n = 18) of CPA varied from 79% to 114% in the range of concentrations studied over a period of 4 months. Mean recoveries (n = 3 or 6) of CPA in wheat, peanuts and rice varied from 70% to 111%, 77% to 116% and 69% to 92%, respectively. The method was successfully applied to the analysis of feed and rice samples artificially infected with the fungal strain Penicillium commune, where the toxin was found at different levels.     

Quantitative determination of rifampicin in aquatic products by stable isotope-dilution high liquid chromatography–tandem mass spectrometry

Rifampicin is a semi-synthetic broad-spectrum antibiotic obtained from rifamycin B. It is one of the most effective first-line antituberculosis drugs and is widely used in clinical practice. In the present study, we describe a rapid and sensitive method for the determination of rifampin in aquatic products by stable isotope-dilution high liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Samples were extracted with the acetonitrile, degreased by hexane, and then concentrated by nitrogen blowing. After separation using a C₁₈ column with a mixture of acetonitrile and water as mobile phase, it was determined by HPLC–MS/MS using the stable isotope-dilution calibration method. The performance of our method was validated. The limit of detection was 0.25 μg kg⁻¹ and the limit of quantification was 0.5 μg kg⁻¹. At the three spiked levels of 0.5, 1.0 and 5.0 μg kg⁻¹, the average recoveries of rifampicin in different aquatic products were between 75.28 and 107.6%, and the relative standard deviation ranged from 0.81 to 13.23%. This method was successfully applied for the determination of rifampin in different kinds of aquatic products and rifampicin residue was found in aquatic products obtained from markets in Beijing, China.     

High-throughput determination of pesticide residues in food commodities by use of ultra-performance liquid chromatography–tandem mass spectrometry

A rapid, simple, and sensitive multiresidue method for analysis of 53 pesticides in fruit and vegetables by ultra-performance liquid chromatography (UPLC) coupled to triple-quadrupole tandem mass spectrometry (MS-MS) has been developed and validated. Prior to analysis, analytes were extracted by use of buffered QuEChERS (quick, easy, cheap, effective, rugged, safe) methodology without further cleanup for non fatty matrices. Chromatographic conditions were optimised in order to achieve a fast separation in multiple reaction monitoring (MRM) mode. Indeed, more than 50 pesticides can be separated in less then 10 min. Four common representative matrices (cucumber, orange, strawberry, and olive) were selected to investigate the effect of different matrices on recovery and precision. Mean recoveries ranged from 70 to 109% with relative standard deviations lower than 20% for all the pesticides assayed in the four selected matrices. The method has been applied to the analysis of 200 vegetable samples, and imidacloprid was the pesticide most frequently found, with concentrations ranging from 0.01 to 1.00 mg kg⁻¹. This methodology combines the advantages of both QuEChERS and UPLC-MS-MS producing a very rapid, sensitive, and reliable procedure which can be applied in routine analytical laboratories.