Liquid Chromatography Tandem Mass Spectrometry as a Tool to Investigate Pesticides and Their Degradation Products

Abstract

The analytical determination of organic structures is a fundamental need in environmental, food and medicinal chemistry, and the chemistry of pesticide compounds is closely involved in this determination because of the environmental and biological transformations that can occur to these molecules. Degradation products often possess higher toxicity than parent substances but unknown structures, and aqueous milieu produce hard-to-solve instrumental problems. The need to analyze low concentrations in polar solutions means that methods in which liquid chromatography is hyphenated to mass spectrometry have a large playing field, which combines trace determination and structural elucidation. An important area of study comprises degradation-simulating models, such as titanium dioxide mediated photocatalytic attacks on different organic structures. HPLC-mass spectrometric studies on pesticides, their metabolites and their degradation products are reviewed.

Control of pesticide residues by liquid chromatography‐mass spectrometry to ensure food safety

“…The enhanced selectivity afforded by MS/MS detection discriminates between target pesticides that were marginally separated by LC. It should be taken into account that the mobile phase is important to obtain a good chromatographic separation, but it also affects the analyte ionization and the sensitivity of the mass spectrometer (Obana et al, 2003; Budde, 2004; Andreu & Picó, 2005; Medana et al, 2005; Careri, Bianchi, & Corradini, 2002; Picó, Blasco, & Font, 2004; Ferrer, García‐Reyes, & Fernández‐Alba, 2005; Nuñez, Moyano, & Galceran, 2005).…”

“…Although the enormous potential of LC‐MS has contributed to the development in the last years of numerous applications, especially in the field of food analysis, a certain number of disadvantages and limitations have been also evidenced affecting both qualitative and quantitative determination (Picó, Blasco, & Font, 2004; Medana et al, 2005; Nuñez, Moyano, & Galceran, 2005). One of these disadvantages is the limited fragmentation obtained under API conditions that can lead to uncertainty in pesticide confirmation.…”

“…There is a growing interest to apply liquid chromatography‐mass spectrometry (LC‐MS) in control of pesticide residues to ensure food safety as depicted in Figure 1, which summarizes the number of articles published from 2000 to 2005 sorted from the ISI Web of Science (Science Citation Index Expanded, Index Chemicus, Current Chemical Reactions, Social Sciences Citation Index, and Arts & Humanities Citation Index) using the keywords “Pesticides,” “Food,” and “Liquid Chromatography‐Mass Spectrometry.” Among these articles, there are several reviews, which have been published since 2000, about some aspects of pesticide residue control by LC‐MS, as applications of some of these instruments in pesticide trace analysis (Hogendoorn & van Zoonen, 2000; Picó et al, 2000; Careri, Bianchi, & Corradini, 2002; Budde, 2004; Picó, Blasco, & Font, 2004; Ferrer, García‐Reyes, & Fernández‐Alba, 2005; Medana et al, 2005; Nuñez, Moyano, & Galceran, 2005) or as representative with other techniques used in the analysis of pesticide residues in food and drinks (Tadeo et al, 2000, 2004; Ahmed, 2001).…”

Analysis of pesticides in water by liquid chromatography‐tandem mass spectrometric techniques

“…Today, much attention is paid to the identification of polar TPs of pesticides (usually hydroxylated and hydrolized derivatives) (Pozo et al, 2001; Lagana et al, 2002; Medana, 2005), although the lack of standards is often the main obstacle encountered in this kind of approaches. In two very extensive studies conducted in this line of research in both Spain (applying QqQ and Q‐TOF) and the USA (Q‐Trap), pesticide TPs were detected at concentrations frequently similar to those of their parent compounds.…”

Highlights of Mass Spectrometric Methodologies in Environmental Pollution

“…To evaluate signal suppression, it is a good practice to perform a matrix-matched calibration (standards in identical or similar matrix than sample to be analyzed) or to use appropriate labeled surrogate and internal standards or application of an efficient clean-up step. Also it should be taken into account that the mobile phase is important to obtain a good chromatographic separation, but it also affects the analyte ionization and the sensitivity of the mass spectrometer (Andreu & Picò , 2005;Medana et al, 2005). Chromatographic separation of ionic compounds can be achieved by different retention mechanisms, mainly, ionexchange and ion-pair reversed-phase liquid chromatography (IP-RPLC).…”