Ion Trap Mass Spectrometry Detector Research Articles

Application of a hybrid large pore mesoporous silica functionalized with β-cyclodextrin as sorbent in dispersive solid-phase extraction. Toward sustainable sample preparation protocols to determine polyphenolic compounds in Arbutus unedo L. fruits by UHPLC-IT-MS/MS

A quick, sensitive and selective analytical reversed-phase method using ultra-high performance liquid chromatography coupled to an ion-trap mass spectrometry detector (UHPLC-IT-MS/MS) was employed for the simultaneous determination of nine phenolic compounds (PCs) in strawberry tree (SBT) berries. The sample treatment included a solid-liquid extraction followed by a dispersive solid-phase extraction (dSPE) procedure using a hybrid large pore mesoporous silica (LP-MS) functionalized with β-cyclodextrin (β-CD) as sorbent material. For this purpose, the initial synthesized LP-MS was modified with β-CD following three different synthetic routes, obtaining three new functionalized materials (denoted LP-MS-β-CD-R1, LP-MS-β-CD-R2 and LP-MS-β-CD-R3). All synthesized materials were comprehensively characterized, showing excellent textural properties, and they were also tested as sorbent materials in the extraction of PCs by comparison of SPE and dSPE procedures. The LP-MS-β-CD-R2 as sorbent material in the dSPE procedure showed the best potential to extract and purify the target PCs, being more effective than the other materials and compared with the SPE procedure. The performance of the proposed dSPE-UHPLC-IT-MS/MS method was validated in terms of selectivity, linearity, LOD, LOQ, trueness, precision, and matrix effect, achieving good analytical method performance and demonstrating its feasibility and practicality for the quantification of PCs in SBT fruits. The analysis of the investigated SBT berries revealed, mainly, high contents of arbutin reaching concentrations up to 5979 µg/g dry weight, followed by catechin (661 µg/g dry weight). Arbutin was, undoubtedly, the major PC determined in all SBT berry samples analyzed, being the most prominent and showing a high concentration compared to that of other polyphenols determined in other red berries.

A comparative study of phenolic composition and antioxidant activity in commercial and experimental seedless table grapes cultivated in a Mediterranean climate

Grapes are important sources of phenolic compounds, which have multiple beneficial effects on human health. Scientific advances in the field of genetics have allowed the production of seedless table grape varieties, which are highly demanded by consumers because of their nutritional value and their easy consumption. In this study, total phenolic content (TPC), radical scavenging activity (RSA) and total anthocyanin content (TAC), were determined in 65 seedless table grape varieties (41 experimental and 24 commercial varieties). Ultra-high performance liquid chromatography coupled to an ion-trap mass spectrometry detector (UHPLC-IT-MS/MS) was used to identify and quantify some phenolic acids, flavan-3-ols, flavonols and stilbenes in 14 experimental varieties. TPC ranged from 17 to 250 mg gallic acid equivalents/100 g fresh weight (FW), RSA ranged from 15 to 269 mg Trolox equivalents/100 g FW and TAC ranged from 0 to 168 mg cyanidin-3-glucoside/100 g FW. The RSA assay showed high correlation (R2 = 0.90) between the TPC and the antioxidant activity of the 65 seedless table grapes analyzed. In the vast majority of the new experimental varieties analyzed, the TPC and TAC were similar to those of some common table grapes with seeds, indicating promising perspectives for their commercialization as potential sources of these bioactive compounds. In 6 grape varieties, high concentrations of catechin, procyanidin B2, epicatechin, quercetin 3-β-d-glucoside, 4-hydroxybenzoic acid, vanillic acid, caftaric acid and rutin were found, which would indicate that the regular intake of these varieties would be highly recommended.

Changes in phenolic composition in olive tree parts according to development stage

The aim of this study was to investigate the changes in the phenolic profile in different organs (buds, flowers, fruits and leaves) from Chemlali olive variety cultivated in the Center of Tunisia according to development stage. Phenolics recovery was carried out using aqueous methanol from freeze-dried powdered tissues. The extracts were then analyzed by using high performance liquid chromatography coupled to time of flight and ion trap mass spectrometry detectors. Qualitatively, secoiridoids, flavonoids, simple phenols, cinnamic acid derivatives and lignans were identified in the analyzed extracts. Quantitatively, floral buds showed the highest phenolic contents compared to the other tissues under study. The highest content of secoiridoids was observed for unripe fruit extract, whereas the highest content of flavonoids was registered for floral buds.

Application of a hybrid ordered mesoporous silica as sorbent for solid-phase multi-residue extraction of veterinary drugs in meat by ultra-high-performance liquid chromatography coupled to ion-trap tandem mass spectrometry

A quick, sensitive and selective analytical reversed-phase multi-residue method using ultra-high performance liquid chromatography coupled to an ion-trap mass spectrometry detector (UHPLC-IT-MS/MS) operating in both positive and negative ion mode was developed for the simultaneous determination of 23 veterinary drug residues (β-blockers, β-agonists and Non-Steroidal Anti-inflammatory Drugs (NSAIDs)) in meat samples. The sample treatment involved a liquid-solid extraction followed by a solid-phase extraction (SPE) procedure. SBA-15 type mesoporous silica was synthetized and modified with octadecylsilane, and the resulting hybrid material (denoted as SBA-15-C18) was applied and evaluated as SPE sorbent in the purification of samples. The materials were comprehensively characterized, and they showed a high surface area, high pore volume and a homogeneous distribution of the pores. Chromatographic conditions and extraction procedure were optimized, and the method was validated according to the Commission Decision 2002/657/EC. The method detection limits (MDLs) and the method quantification limits (MQLs) were determined for all the analytes in meat samples and found to range between 0.01–18.75μg/kg and 0.02–62.50μg/kg, respectively. Recoveries for 15 of the target analytes ranged from 71 to 98%. In addition, for comparative purpose SBA-15-C18 was evaluated towards commercial C18 amorphous silica. Results revealed that SBA-15-C18 was clearly more successful in the multi-residue extraction of the 23 mentioned analytes with higher recovery values. The method was successfully tested to analyze prepacked preparations of mince bovine meat. Traces of propranolol, ketoprofen and diclofenac were detected in some samples.

Rapid and simple determination of acrylamide in conventional cereal-based foods and potato chips through conversion to 3-[bis(trifluoroethanoyl)amino]-3-oxopropyl trifluoroacetate by gas chromatography coupled with electron capture and ion trap mass spectrometry detectors

A new, simple, rapid and fully validated method based on gas chromatography coupled with Electron capture and ion trap mass spectrometry detectors (GC-ECD and GC-IT/MS) is presented for quantitative analysis of acrylamide contaminant in conventional cereal-based foods and potato chips. Before analysis acrylamide was efficiently derivatized with trifluoroacetic anhydride, the effects of temperature, reaction time and catalyst on the acylation reaction were evaluated. Chromatographic analysis was performed on SE-54 capillary column; good retention and peak response of the acrylamide derivative achieved under the optimal conditions. The analytical method has been fully validated by assessment of the following parameters: LODs and LOQs (1 and 25ngg−1 by GC-ECD and 2 and 36ngg−1 by GC-IT/MS, with a Relative Standard Deviations <4 and <6, respectively), linearity (R2 above 0.981 in the range 0.005–50μgg−1) and extraction recovery (ranging between 91% and 99%, RSD below 4.0, for acrylamide spiked at levels of 1, 20, 50 and 100ngg−1). Furthermore, the method proposed requires no clean-up step of the acrylamide derivative to be performed prior to injection.The developed method has been successfully applied to determine acrylamide in different commercial cereal-based foods (including French fries and potato chips).

Study of XAD-2 adsorbent for the enrichment of trace levels of phthalate esters in hydroalcoholic food beverages and analysis by gas chromatography coupled with flame ionization and ion-trap mass spectrometry detectors

An analytical method based on solid-phase extraction (SPE) with Amberlite XAD-2 adsorbent used as stationary phase for determining phthalate esters (PAEs) in hydroalcoholic food beverages by GC–FID (and peak confirmation by GC–IT/MS) has been set up. The XAD-2 resin shows excellent properties for determining PAEs in solutions at very large alcoholic range (10–40% v/v): 500mL of hydroalcoholic solution spiked with a PAE mixture solution (20pgμL−1 of each PAE) and containing 25gL−1 of NaCl are passed onto a cartridge containing 500mg XAD-2 adsorbent and re-extracted for GC analysis. The effects of NaCl concentration (0, 12, 25 and 50gL−1) and different solvents (CS2, toluene, acetone, n-hexane, ethyl acetate) are extensively studied as well the PAE recoveries both in hydroalcoholic aqueous solutions (ranging between 94% and 103% with a Relative Standard Deviation, RSD, below 8.3) and spiked (5, 10 and 25pgμL−1 of each PAE) real samples (between 90% and 106% with a RSD below 9.9). The correlation coefficients (R2) of each PAE vary between 0.9830 and 0.9950 and they are calculated in the linear range 5–100pgμL−1. The limits of detection (LOD) in GC–FID vary between 1.21 and 2.51pgμL−1 (RSD⩽11.1) whereas the Limits of Quantification (LOQ) range between 2.42 and 5.03pgμL−1 (RSD⩽8.9) whereas the infra-day and inter-day repeatabilities calculated as RSD for hydroalcoholic solutions, are between 6.5% and 13.7%.

Microwave‐assisted extraction of edible Cicerbita alpina shoots and its LC‐MS phenolic profile

Crude extracts obtained from the edible shoots of Cicerbita alpina using microwave-assisted extraction have been qualitatively profiled by liquid chromatography coupled with an ion trap mass spectrometry detector and an electrospray ionization interface (LC/ESI-MS(3) ) for their phenolic content. The main challenge of the present investigation was to create a working strategy designed to obtain a rich phenolic profile despite the limited amount of starting plant material and phytochemical data available. The best extraction conditions (temperature 90 °C; time 5 min; solvent methanol:water 50:50; sample weight 3 g) were achieved using a full factorial 2(4) experimental design. Fifteen compounds, including flavonoid conjugates and phenolic acid derivatives, were detected and tentatively identified. The total phenolic content varied from 93.58 mg g(-1) gallic acid equivalents (GAE), for the cultivated plant to 10.54 mg g(-1) GAE for the wild one, whereas the total flavonoid content varied from 145.00 mg g(-1) rutin for the cultivated plant to 25.22 mg g(-1) rutin for the wild one. A total of 11 compounds are herein reported, for the first time, as coming from this plant source.

Sampling of organophosphorus pesticides at trace levels in the atmosphere using XAD-2 adsorbent and analysis by gas chromatography coupled with nitrogen–phosphorus and ion-trap mass spectrometry detectors

This paper shows an analytical methodology based on solid-phase extraction by XAD-2 adsorbent and gas chromatography (GC) coupled with nitrogen-phosphorus (NPD) and ion-trap mass spectrometry detectors (ITMS) in negative chemical ionization (NCI) mode analyses for investigating organophosphorus pesticides (OPs) at trace levels (in nanograms per cubic meter) in the atmosphere: in particular, we set up a procedure for analyzing 38 OPs. For the analytical methodology linearity responses have been obtained in GC-NPD (r > 0.9982) and GC-NCI/ITMS (r > 0.9974) in a large linearity range (0.10-500 pg μL(-1) in both cases) whereas the limits of detection range between 0.01 and 0.03 pg μL(-1) in both the techniques with a relative standard deviation (RSD) below 9.0 in both cases. Particular attention has been devoted to investigate the effect of different solvents (n-hexane, benzene, chloroform, carbon disulfide, acetonitrile) on the OP recovery as well the breakthrough volumes have been evaluated (100% recovery up to 4,286 L g(-1)). The study has also investigated the OP recoveries at different sampling flow rates (1.5 and 2.0 L min(-1)) for determining the optimal conditions for sample collection. Finally, the whole approach has been successfully applied to real samples collected in four different areas in the Molise region (Central Italy) during different seasons: the results show that parathion-ethyl, dimethoate, omethoate, and malathion are present in all periods at low levels (ranging between 70 and 10 ng m(-3)): their levels in such periods can be correlated with spraying as well atmospheric conditions favoring the dispersion/accumulation of these pollutants.

Evolution of tebuconazole residues through the winemaking process of Mencía grapes

The removal of tebuconazole residues during the winemaking process, applied initially to red must elaborated from Mencia variety grapes from A.O.C. Valdeorrras (Ourense, N.W. Spain), was studied. Analytical determination of tebuconazole residues in grapes, musts and wines were perfomed by gas chromatography equipped with an ion trap mass spectrometry detector (GC–ITMS). Tebuconazole is retained on the solid matter (cakes and lees) and clarification agent. The eliminated percentage of tebuconazole in the final wine is 86%. The influence of this fungicide on the fermentative activity of Saccharomyces cerevisiae yeast and the Oenococcus oeni was also studied through in vitro assays. Liquid chromatography equipped with triple quadrupole mass spectrometer (LC–MS/MS) was used to determine tebuconazole residues in synthetic must and wine used for in vitro assays. No effect on the alcoholic or malolactic fermentation was observed; and no degradation of tebuconazole originated by these microorganisms was registered.

Comparison of three gas chromatography methods for the determination of slip agents in polyethylene films

Polymers require the use of some slip agents, such as oleamide and erucamide, in order to reduce their friction coefficient and to make films easier to handle. In this communication, three analytical methods consisting in pressurized liquid extraction (PLE) and gas chromatography (GC) are used to determine oleamide and erucamide in polyethylene films. The sample was extracted with pure isopropanol (two times) at 105 °C for 16 min. Then, the liquid extract containing oleamide and erucamide was analyzed by GC and three different detection systems: flame ionization detector (FID), thermoionic selective detector (TSD) and ion-trap mass spectrometry detector (MSD). Oleamide and erucamide were separated using a 30 m × 0.25 mm (I.D.) 5% phenyl–95% dimethyl–polysiloxane capillary column in 12 min. The chromatographic methods were characterized and compared in terms of repeatability, linearity and sensitivity. The GC-FID and GC-TSD methods were linear up to about 60 μg ml −1, whereas the linear range for the GC-MSD method was shorter, from 20.5 to 42 μg ml −1. LODs identified with GC-MSD were two times higher than those identified with the other two methods. Repeatability values (expressed as relative standard deviation) of less than 2.5% were found for FID and TSD but they were above 10% for MSD. Finally, each method was applied to determine the content of erucamide and oleamide in several polyethylene films and the results obtained were compared with those obtained from the nitrogen content measured by pyrolisis and gas-phase chemiluminescence. No significant differences were observed between the results of the methods.

Congener specific determination of toxaphene residues in fish liver oil using gas chromatography coupled to ion trap MS/MS

A new approach to the determination of six toxaphene congeners in edible stuff has been accomplished. The analytical procedure presented in this paper involves a single-step cleanup process prior to the analysis. A solution containing three 13C labelled polychlorinated biphenyls was used as internal standard and tetrachloronaphtalene was used as injection standard. The analytical technique used was gas chromatography coupled to ion trap mass spectrometry detector in MS/MS mode. The parameters affecting the successive fragmentations were discussed and optimized. The limits of detection ranged from 2 to 49 pg μl −1. The toxaphene congeners were determined in two different fish liver oil pills sold in Spain as a supplementary vitamin support.

Triad case study: Marine corps base camp pendleton

The U.S. Navy Public Works Center (PWC) Environmental Department San Diego, California is home to the Navy west coast Site Characterization and Analysis Penetrometer System (SCAPS). SCAPS has been extensively used at several Navy sites since 1995 to provide real-time, highdensity data sets. The United States Environmental Protection Agency’s (EPA’s) Triad approach provided an ideal framework for optimizing the use of the Navy SCAPS during a volatile organic compound (VOC) source investigation at Installation Restoration Site 1114 at Marine Corps Base Camp Pendleton. All three elements of Triad, systematic planning, dynamic work strategy, and use of real time measurement tools, were implemented to manage decision uncertainty and expedite the site management process. The investigation was conducted using the Navy SCAPS outfitted with a cone penetrometer), membrane interface probe and a direct sampling ion trap mass spectrometry detector which allowed for real- time collection of over 690 feet of continuous lithologic information and VOC concentration data. These data were used collaboratively with 24-hour turnaround EPA 8260B VOC groundwater results from temporary direct-push wells to support the conclusion of a limited source area. Implementation of the Triad approach for this investigation provided an expedited high-density data set and a refined Conceptual Site Model (CSM) in real time that resulted in cost savings estimated at $2.5 M and reduction of the site characterization and cleanup schedule by approximately 3 years. This project demonstrates how EPA’s Triad approach can be applied to streamline the site characterization and cleanup process while appropriately managing decision uncertainty in support of defensible site decisions.

Triad case study: Marine Corps Base Camp Pendleton

AbstractThe U.S. Navy Public Works Center (PWC) Environmental Department, San Diego, California, is home to the Navy West Coast Site Characterization and Analysis Penetrometer System (SCAPS). SCAPS has been extensively used at several Navy sites since 1995 to provide real‐time, high‐density data sets. The U.S. Environmental Protection Agency's Triad approach provided an ideal framework for optimizing the use of the Navy SCAPS during a volatile organic compound (VOC) source investigation at Installation Restoration Site 1114 at Marine Corps Base Camp Pendleton. All three elements of Triad—systematic planning, dynamic work strategy, and use of real‐time measurement tools—were implemented to manage decision uncertainty and expedite the site management process. The investigation was conducted using the Navy SCAPS, outfitted with a cone penetrometer, membrane interface probe, and a direct sampling ion trap mass spectrometry detector, which allowed for real‐ time collection of over 690 feet of continuous lithologic information and VOC concentration data. These data were used collaboratively with 24‐hour turnaround US EPA 8260B VOC groundwater results from temporary direct‐ push wells to support the conclusion of a limited source area. Implementation of the Triad approach for this investigation provided an expedited high‐density data set and a refined conceptual site model (CSM) in real time that resulted in cost savings estimated at $2.5M and reduction of the site characterization and cleanup schedule by approximately three years. This project demonstrates how the US EPA's Triad approach can be applied to streamline the site characterization and cleanup process while appropriately managing decision uncertainty in support of defensible site decisions. © 2004 Wiley Periodicals, Inc.