Quantitation and accurate mass analysis of pesticides in vegetables by LC/TOF-MS
TL;DR: Robustness and applicability of the method was validated for the analysis of market vegetable samples and it was shown that LC/TOF-MS analysis is a powerful tool for identification of pesticides in vegetables.
Abstract: A quantitative method consisting of solvent extraction followed by liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS) analysis was developed for the identification and quantitation of three chloronicotinyl pesticides (imidacloprid, acetamiprid, thiacloprid) commonly used on salad vegetables. Accurate mass measurements within 3 ppm error were obtained for all the pesticides studied in various vegetable matrixes (cucumber, tomato, lettuce, pepper), which allowed an unequivocal identification of the target pesticides. Calibration curves covering 2 orders of magnitude were linear over the concentration range studied, thus showing the quantitative ability of TOF-MS as a monitoring tool for pesticides in vegetables. Matrix effects were also evaluated using matrix-matched standards showing no significant interferences between matrixes and clean extracts. Intraday reproducibility was 2−3% relative standard deviation (RSD) and interday values were 5% RSD. The precision (standard deviation) of the m...
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TL;DR: Issues related to matrix effects are reviewed, focusing on quantitative pesticide analysis, but also paying attention to expertise with respect to Matrix effects acquired in other application areas of LC-MS, especially quantitative bioanalysis in the course of drug development.
Abstract: Combined liquid chromatography-mass spectrometry using electrospray or atmospheric-pressure chemical ionization has become an important tool in the quantitative analysis of pesticide residues in various matrices in relation to environmental analysis, food safety, and biological exposure monitoring. One of the major problems in the quantitative analysis using LC-MS is that compound and matrix-dependent response suppression or enhancement may occur, the so-called matrix effect. This article reviews issues related to matrix effects, focusing on quantitative pesticide analysis, but also paying attention to expertise with respect to matrix effects acquired in other application areas of LC-MS, especially quantitative bioanalysis in the course of drug development.
386 citations
TL;DR: A rapid and simple method for simultaneous analysis of four neonicotinoid insecticides including acetamiprid, imidacloprid, thiacloprid and thiamethoxam in fruit and vegetable matrices has been developed and could be utilized for monitoring of pesticides residues.
234 citations
TL;DR: This paper serves as a guide for those working in the analytical field of pesticides, as a powerful tool for finding non-targets and unknowns in environmental samples that have not been previously included in any of the routine target multi-residue methods.
201 citations
TL;DR: The use of LC coupled to (quadrupole) time-of-flight mass spectrometry (LC-(Q)ToF-MS) to determine the presence of target and non-target pesticides in water and food and the performance of such techniques is depicted in terms of accurate mass measurement, fragmentation, and selectivity.
Abstract: Liquid chromatography coupled to mass spectrometry (LC-MS) is an excellent technique to determine trace levels of polar and thermolabile pesticides and their degradation products in complex matrices. LC-MS can be equipped with several mass analyzers, each of which provides unique features capable to identify, quantify, and resolve ambiguities by selecting appropriate ionization and acquisition parameters. We discuss in this review the use of LC coupled to (quadrupole) time-of-flight mass spectrometry (LC-(Q)ToF-MS) to determine the presence of target and non-target pesticides in water and food. This technique is characterized by operating at a resolving power of 10,000 or more. Therefore, it gives accurate masses for both parent and fragment ions and enables the measurement of the elemental formula of a compound achieving compound identification. In addition, the combination of quadrupole-ToF permits tandem mass spectrometry, provides more structural information, and enhances selectivity. The purpose of this article is to provide an overview on the state of art and applicability of liquid chromatography time-of-flight mass spectrometry (LC-ToF-MS), and liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS) for the analysis of pesticides in environmental matrices and food. The performance of such techniques is depicted in terms of accurate mass measurement, fragmentation, and selectivity. The final section is devoted to describing the applicability of LC-(Q)ToF-MS to routine analysis of pesticides in food matrices, indicating those operational conditions and criteria used to screen, quantify, and identify target and "suspected" pesticides and their degradation products in water, fruits, and vegetables. The potential and future trends as well as limitations of LC-(Q)ToF-MS for pesticide monitoring are highlighted.
186 citations
Cites background or methods from "Quantitation and accurate mass anal..."
...…matrix complexity on the accuracy of mass measurement showed no significant differences in the accuracy obtained in the various matrix-matched standards compared to those prepared with pure solvent, the error being kept 5 ppm, with an average of 1 ppm for most pesticides (Ferrer et al., 2005c)....
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...Using matrix-matched standards and LC-ToF-MS, Ferrer et al. reports LOD (using a signal to noise ratio of 3) between 0.9 and 30mg/kg for several pesticides (Ferrer, Garcı́aReyes, & Fernandez-Alba, 2005b; Ferrer et al., 2005c)....
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...Within the field of food analysis, a multi-residue methodology using LC-ToF-MS was used for the quantitative routine Mass Spectrometry Reviews DOI 10.1002/mas 871 analysis of 15 pesticides in several types of fruits and vegetables (Ferrer et al., 2005c)....
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TL;DR: The LC-MS/MS method was satisfactorily validated for the analysis of 150 agricultural samples and showed excellent linearity, precision and precision for all compounds.
176 citations
References
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TL;DR: In this paper, an overview is given on pesticide-residue determination in environmental and food samples by liquid chromatography/mass spectrometry/mass spectrum analysis (LC/MS/MS).
Abstract: An overview is given on pesticide-residue determination in environmental and food samples by liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS). Pesticides comprise a large number of substances that belong to many completely different chemical groups, the only common characteristic is that they are effective against pests. They still constitute a challenge in MS because there is no collective pathway for fragmentation. A brief introduction to the theory of tandem MS permits a discussion of which parameters influence the ionization efficiency when the ions are subjected to different actions. Emphasis is placed on the different tandem MS instruments: triple and ion-trap quadrupoles, and hybrid quadrupole time-of-flight (Q-TOF), including advantages and drawbacks, typical detection limits, and ion signals at low concentrations. The instrumental setup, as well as LC and mass spectrometric experimental conditions, must be carefully selected to increase the performance of the analytical system. The capacity of each instrument to provide useful data for the identification of pesticides, and the possibility to obtain structural information for the identification of target and non-target compounds, are discussed. Finally, sample preparation techniques and examples of applications are debated to reveal the potential of the current state-of-the-art technology, and to further promote the usefulness of tandem MS.
261 citations
TL;DR: The excellent sensitivity and selectivity of LC-MS-MS method allowed quantitation and identification at low levels also in difficult matrices with a run time of 20 min.
234 citations
TL;DR: A new multi-residue method for determination of pesticide residues in a wide variety of fruit and vegetables, using the National Food Administration (NFA) ethyl acetate extraction and determination by means of LC-MS/MS, is presented.
198 citations
TL;DR: The main features of mass spectrometry combined with separation instruments are discussed in food-related analysis and the development and application of matrix-assisted laser desorption ionization (MALDI) and electrospray (ESI) to the analysis of peptides and proteins in food is discussed.
181 citations
TL;DR: Determination of 3 neonicotinoid insecticides, nitenpyram, imidacloprid, and acetamiprid, was studied and agriculturally incurred pesticides at 0.08-0.14 mg/kg were designated with UV spectra compared with respective reference standards.
Abstract: Determination of 3 neonicotinoid insecticides, nitenpyram, imidacloprid, and acetamiprid, was studied. Vegetables and fruits were extracted with acetonitrile. The crude extract was passed through a weak anion-exchange cartridge (PSA). The effluent was subjected to silica gel cartridge. Imidacloprid and acetamiprid were eluted with 10 mL of 4:6 (v/v) acetone/hexane, followed by nitenpyram with acetone (20 mL). Pesticides were determined by HPLC with a C-18 column and diode-array detection system. Imidacloprid and acetamiprid were recovered at about 90% at the spike levels with 0.2 and 2 mg/kg in cucumber, potato, tomato, eggplant, Japanese radish, and grape. Nitenpyram was recovered at 64-80%. Relative standard deviations were less than 10% throughout all the recovery tests. In the residue analysis, agriculturally incurred pesticides at 0.08-0.14 mg/kg were designated with UV spectra compared with respective reference standards.
176 citations