An evaluation method for determination of non-polar pesticide residues in animal fat samples by using dispersive solid-phase extraction clean-up and GC-MS

Abstract

A rapid and easy method has been proposed, optimized and evaluated for quantitative determination at trace level of a representative group of non-polar pesticides in fat samples. The method includes n-hexane-saturated acetonitrile extraction, fat precipitation by cooling pre clean-up followed by dispersive solid-phase extraction (d-SPE) based on QuEChERS procedure clean-up. Determination was performed by gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. Efficiency of the d-SPE clean-up step was evaluated by comparison with fat oxidation treatment and gel permeation chromatography. Different combinations of d-SPE extraction reagents and sample amounts were tested in order to minimize matrix co-extractives and interferences. Best recoveries were obtained with 1200 mg of MgSO(4), 400 mg of end-capped C(18), 400 mg of PSA and 1 g of sample amount. SIM method, matrix effect, precision, and accuracy were evaluated with spiked pork fat samples for 38 representative pesticides. Results of this study showed that this technique is applicable in routine analysis for its application into monitoring programs. It simplifies time-consuming clean-up steps and allows a satisfactory long-term chromatographic performance.

Pesticide Residue Analysis in Animal Origin Food: Procedure Proposal and Evaluation for Lipophilic Pesticides

“…In addition, this technique consumed smaller solvent amount (13 mL acetonitrile + 3 mL nhexane). Finally, acceptable recovery values were obtained for all studied pesticides [39].…”

“…Finally, 4 mL of cleaned supernatant is evaporated under nitrogen stream until near dryness, and then dissolved in a volume of internal standard solution (0.5 mL for GC-MS or 0.25 mL for GC-MS/MS). Then, the solution is transferred to autosampler vials for analysis [39].…”

“…A LVI procedure based on a PTV injection was employed, in order to improve the detection limits of the target compounds in the analysis, The cleanliness of the obtained extracts with the developed method allows longer working sequences with acceptable drifts and a significantly reduce of instrumental maintenance. However, matrix interferences for some pyrethroids, as well as sensitivity limitations, were observed [39].…”

Analysis of pesticides residues in environmental water samples using multiwalled carbon nanotubes dispersive solid‐phase extraction

“…Its inherent advantages such as high enrichment efficiency, stability, higher environmentally friendliness and low cost has proved it to be a powerful sample handling method. However, a modification of the conventional SPE procedure called dispersive SPE (dSPE) has emerged to carry out the extraction and not as a clean‐up step as it has been traditionally used . In this mode, the sorbent is directly added into the sample solution without any conditioning and consequently, analytes are extracted in the bulk solution and not in a column, cartridge or disk.…”

Screening methodologies for the determination of water contaminant residues by compact disk technology

“…[37][38][39][40] The cost of the analysis that would truly represent the overall water quality status using mentioned techniques would be high, since chemically different compounds should be analysed in a single run. This is the reason why new alternative techniques are emerging to deal with this problem.…”