Clean-up of cereal extracts for gas chromatography–tandem quadrupole mass spectrometry pesticide residues analysis using primary secondary amine and C18

The level of co-extracted matrix in wheat and oat extracts obtained by the QuEChERS method (EN 15662) is high and the occurrence of free fatty acids generates a major matrix peak in TIC chromatograms (rt. 13-22min). Matrix can compromise the analytical performance in pesticide analysis using GC-MS/MS. In order to reduce the amount and the effects of matrix we tested the effect of using six different amounts of primary secondary amine (PSA) (0, 25, 50, 100, 150 and 200mg/ml extract) with and without the addition of six different amounts of C18 (0, 25, 50, 100, 150 and 200mg/ml extract) in the dispersive solid phase extraction (dSPE) procedure. dSPE clean-up using 25mg/ml extract significantly reduced the major matrix peak observed for wheat extracts. Higher amounts of PSA reduced the analytical response for iprodione and malathion. For oat extract 50-150mg PSA/ml extract was needed to obtain equally low intensity of the matrix peak. For oat the analytical responses of the target pesticides generally increased with increasing amount of PSA. C18 had no significant effect on the intensity of the major matrix peaks and even resulted in lower analytical responses for several of the target pesticides. Based on the present study it is concluded that the optimal dSPE clean-up procedure employs 25mg PSA/ml extract for wheat and 150mg PSA/ml extract for oat

Green Aspects of Techniques for the Determination of Currently Used Pesticides in Environmental Samples

Pesticides are among the most dangerous environmental pollutants because of their stability, mobility and long-term effects on living organisms. Their presence in the environment is a particular danger. It is therefore crucial to monitor pesticide residues using all available analytical methods. The analysis of environmental samples for the presence of pesticides is very difficult: the processes involved in sample preparation are labor-intensive and time-consuming. To date, it has been standard practice to use large quantities of organic solvents in the sample preparation process; but as these solvents are themselves hazardous, solvent-less and solvent-minimized techniques are becoming popular. The application of Green Chemistry principles to sample preparation is primarily leading to the miniaturization of procedures and the use of solvent-less techniques, and these are discussed in the paper

Critical assessment of performance characteristics of methods applicable in determination of multiple residues of modern pesticides in drinking water and foodstuffs.

The main objective of the presented dissertation was to improve two important performance characteristics of methods applicable for determination of multiple residues of modern pesticides in drinking water and foods: the analysis time and the sample throughput. In gas chromatography, which is the prevailing determinative technique in pesticide multiresidue analysis, two significant trends, both potentially contributing to the increased sample throughput, can be observed. the use of gas chromatography-mass spectrometry as a primary tool for determination of analytes and attempts to increase speed of GC analysis.Available from STL, Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi