Application of gas chromatography–(triple quadrupole) mass spectrometry with atmospheric pressure chemical ionization for the determination of multiclass pesticides in fruits and vegetables

Abstract

A multi-residue method for the determination of 142 pesticide residues in fruits and vegetables has been developed using a new atmospheric pressure chemical ionization (APCI) source for coupling gas chromatography (GC) to tandem mass spectrometry (MS).Selected reaction monitoring (SRM) mode has been applied, acquiring three transitions for each compound. In contrast to the extensive fragmentation typically obtained in classical electron ionization (EI), the soft APCI ionization allowed the selection of highly abundant protonated molecules ([M+H] + ) as precursor ions for most compounds. This was favorable for both sensitivity and selectivity. Validation of the method was performed in which both quantitative and qualitative parameters were assessed using orange, tomato and carrot samples spiked at two levels, 0.01 and 0.1 mg/kg. The QuEChERS method was used for sample preparation, followed by a 10-fold dilution of the final acetonitrile extract with a mixture of hexane and acetone. Recovery and precision were satisfactory in the three matrices, at both concentration levels. Very low limits of detection (down 0.01 g/kg for the most sensitive compounds) were achieved. Ion ratios were consistent and identification according to EU criteria was possible in 80% (0.01 mg/kg) to 96% (0.1 mg/kg) of the pesticide/matrix combinations. The method was applied to the analysis of various fruits and vegetables from the Mediterranean region of Spain.

A review of recent developments and trends in the QuEChERS sample preparation approach

“…The described below examples of the QuEChERS method application in pesticides residues extraction are summarized in Table 3. Cherta et al developed a method applying a GC-(QqQ)/MS with APCI for the determination of 142 pesticide residues in fruits and vegetables according to the official 2007.01AOAC QuEChERS procedure [45]. The elaborated method was successfully validated for the simultaneous identification and quantification of 142 pesticides in orange, tomato and carrot matrices at 0.01 and 0.1 mg kg -1 with satisfactory recoveries ranging between 70% and 120% for most investigated compounds in all the sample matrices [45].…”

“…Cherta et al developed a method applying a GC-(QqQ)/MS with APCI for the determination of 142 pesticide residues in fruits and vegetables according to the official 2007.01AOAC QuEChERS procedure [45]. The elaborated method was successfully validated for the simultaneous identification and quantification of 142 pesticides in orange, tomato and carrot matrices at 0.01 and 0.1 mg kg -1 with satisfactory recoveries ranging between 70% and 120% for most investigated compounds in all the sample matrices [45]. Applying a GC-MS/MS technique, Hou et al developed a method for the determination of 124 pesticides in rice by modified QuEChERS extraction [46].…”

Multi-class determination of undesirables in aquaculture samples by gas chromatography/tandem mass spectrometry with atmospheric pressure chemical ionization: A novel approach for polycyclic aromatic hydrocarbons

“…Matrix effects observed under GC-APCI-MS come from the GC liner (normally signal enhancement) and from the APCI source (normally signal suppression) [27]. As a summary of the matrix effect study for 9 out of 19 matrices (where different dilution factors were tested: crude extract, 5-fold, 10-fold and 20-fold dilution), signal enhancement/suppression was observed for: i) 36% of the combinations matrix/PAHs, 58% for matrix/pesticides and 52% for matrix/PCBs (crude extract); ii) 35% for matrix/PAHs, 46% for matrix/pesticides and 17% for matrix/PCBs (5-fold dilution factor); iii) 26% of matrix/PAHs, 33% for matrix/pesticides and 14% for matrix/PCBs (10-fold dilution factor); and iv) 11% for matrix/pesticides (20-fold dilution factor).…”

“…In the last years, the application of atmospheric pressure chemical ionization (APCI) source in combination with last generation triple quadrupole instruments has made possible to notably increase sensitivity and selectivity of the determination of organic contaminants in food safety, environment and doping control fields [27][28][29][30] in selected reaction monitoring (SRM) based methods. The improved performance of GC-APCI-MS/MS is more than welcome in the aquaculture field, where the analysis of a wide diversity of "difficult" matrices (oils, plant ingredients, marine ingredients, terrestrial animal ingredients, fish, etc.)…”

Potential of gas chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry for screening and quantification of hexabromocyclododecane

“…The new soft atmospheric pressure chemical ionization (APCI) source has already been satisfactorily applied for GC-amenable compounds such as pesticides, polycyclic aromatic hydrocarbons (PAHs), PBDEs and, very recently dioxins/furans (PCDDs/PCDFs) [11,12].…”