Analytical Study of Trichlorfon Residues in Kaki Fruit and Cauliflower Samples by Liquid Chromatography−Electrospray Tandem Mass Spectrometry

Abstract

A detailed analytical study on trichlorfon residues in selected vegetables samples has been carried out, focused on the reliable quantification and confirmation of this compound, and on stability of residues under storage. As a consequence, a rapid and sensitive LC-ESI-MS/MS method has been developed for the determination of residues of this insecticide in kaki fruit (flesh and peel) and cauliflower samples. Extraction was performed with acetonitrile using a high-speed blender. After 4-fold dilution of the extract with water, 20 microL was directly injected in the LC-ESI-MS/MS system (triple quadrupole), using matrix-matched standards calibration for quantification. Under optimized MS/MS conditions, limit of detections between 0.006 and 0.013 mg/kg were reached, and a limit of quantification of 0.05 mg/kg was established, with a runtime of only 15 min. Recoveries from spiked blank samples at 0.05 and 0.5 mg/kg were in the range 83-101% with relative standard deviations lower than 10%. The method was applied to treated and untreated samples collected from field residues trials, using quality control samples analysis for the evaluation of the method. Despite the acquisition of two MS/MS transitions in selected reaction monitoring mode, the analysis of treated samples revealed the presence of a chromatographic peak close to the analyte that corresponded to a trichlorfon isobaric compound that shared the same MS/MS transitions. This unusual situation in LC-MS/MS-based procedures required the application of an efficient chromatographic separation to avoid this interference. All experiments have been made in compliance with the principles of Good Laboratory Practices (GLP) and following the European SANCO guidelines for pesticides residue analysis (PRA).

Dissipation kinetics, safety evaluation, and preharvest interval assessment of trichlorfon application on rice

“…However, trichlorfon is still extensively used in agricultural practice on a global scale, and its product volume is even increasing in the developing countries. There have been studies regarding trichlorfon residues on some animals and cabbage (Ngoh and Cullison 1996;Blasco et al 2002;Brito et al 2002;Grimalt et al 2006; Barkat et al 2009;Hem et al 2010;Li et al 2011;Meng et al 2012;Xin et al 2013;Zhao et al 2014;Xue et al 2015).…”

Quick and Label-Free Detection for Coumaphos by Using Surface Plasmon Resonance Biochip

“…China stipulates that the residues of Coumaphos in vegetables and fruits must be lower than 0.05 mg/kg [16]. Currently, it can be detected through methods of chromatography such as low pressure gas chromatography-mass spectroscopy (LP GC-MS) [17]–[20], high performance liquid chromatography (HPLC) [21]–[23] and thin layer chromatography (TLC) [24]–[25]. Additionally the wave spectrum method [26]–[28] and enzyme-linked immunosorbent assay (ELISA) [29]–[30], are also used.…”

Determination of Trichlorfon Pesticide Residues in Milk via Gas Chromatography with μ-Electron Capture Detection and GC-MS

“…Trichlorfon (2,2,2-trichloro-1-hydroxyethylphosphonate, DEP) is an organophosphorus insecticide that has been widely used in protection of field and fruit crops. Since trichlorfon is decomposed to the generally more toxic, organophosphate insecticide dichlorvos, causing serious damage on animals and human beings at pH 6 to 8 in aqueous media (Akhtar, 1982 ; Doherty et al ., 1996 ; Talebpour et al ., 2006 ; Grimalt et al ., 2006 ; Catalgol et al ., 2007 ; Guimaraes et al ., 2007) , monitoring the trace level of trichlorfon in food products is essential for human health protection and environmental control (Zhu et al ., 2008) . Animals can accumulate such substances from contaminated feed and water or from insecticide practices in stables.…”

“…An indirect source of organophosphorus can be represented by animal-derived products (Lopes et al ., 2006) . Trichlorfon is an inhibitor of cholinesterase activity, possible due to in vivo conversion to dichlorvos (Grimalt et al ., 2006) . Like all organophosphorus pesticides, trichlorfon is readily absorbed through the skin, subsequently excreted in the urine, and rapidly dechlorinated to dichlorvos in the body.…”

“…Trichlorfon residues in fruit and vegetables have been determined until now by gas chromatography with flame photometric detection (FPD) and electron capture detection (ECD). Recently, the use of GC coupled to mass spectrometry (MS) has been considered a suitable approach to improve selectivity and sensitivity (Grimalt et al ., 2006) ; it is thermally labile and decomposes when analyzed by GC using a heated injector (Ngoh and Cullison, 1996) . Analysis of trichlorfon residues has been reported using gas chromatography coupled with FID (Talebpour et al ., 2006) ; FPD (Iwata et al ., 1979 ; Sheets et al ., 1982 ; Maitlen and Halfhill, 1985) ; NPD (Schultz et al ., 1971 ; Ngoh and Cullison, 1996) and mass spectrometry (Aroa et al ., 2002 ; Brito et al ., 2002 ; Talebpour et al ., 2006) , and by high performance liquid chromatography (HPLC) (Arao et al ., 2002 ; Talebpour et al ., 2006 ; Zhu et al ., 2008) .…”