Influence of QuEChERS modifications on recovery and matrix effect during the multi-residue pesticide analysis in soil by GC/MS/MS and GC/ECD/NPD
Environ Sci Pollut Res
Influence of QuEChERS modifications on recovery and matrix effect during the multi-residue pesticide analysis in soil by GC/MS/MS and GC/ECD/NPD
Bożena Łozowicka 0 1
Ewa Rutkowska 0 1
Magdalena Jankowska 0 1
0 Plant Protection Institute - National Research Institute, Laboratory of Pesticide Residues , Chelmonskiego 22, Postal code: 15-195 Bialystok , Poland
1 Responsible editor: Roland Kallenborn
2 Ewa Rutkowska
A QuEChERS extraction followed by GC/MS/MS and GC-μECD/NPD for 216 pesticide and metabolites determination in soil simultaneously were developed and compared. Volume of water, volume and polarity of solvent, and cleanup sorbents (C18, GCB, PSA) were optimized. The QuEChERS with and without purification step were applied to estimate effectiveness of the method. The recovery and matrix effect (ME) were critical parameters within each tested procedure. The optimal method without cleanup was validated. Accuracy (expressed as recovery), precision (expressed as RSD), linearity, LOQ, and uncertainty were determined. The recoveries at the three spiking levels using matrix-matched standards ranged between 65 and 116% with RSD ≤17 and 60-112% with RSD ≤18% for MS/MS and μEC/NP, respectively. The LOQ ranged from 0.005-0.01 mg/kg for MS/MS to 0.05 mg/kg for μEC/NP. The ME for most of pesticides resulted in enhancement of the signal and depended on the analyte and detection system: MS/MS showed ME from −25 to 74%, while μEC/NP from −45 to 96%. A principal component analysis was performed to explain the relationships between physicochemical parameters and ME of 216 pesticides. The QuEChERS protocol without the cleanup step is a promising option to make the method less expensive and
Pesticide; Soil; Optimization; Multi-residue method; QuEChERS; Gas chromatography
-
faster. This methodology was applied in routine analysis of
263 soil samples in which p,p’ DDT was the most frequently
detected (23.5% of samples) and pendimethalin with the
highest concentration (1.63 mg/kg).
Introduction
Soil is an important resource of agriculture which has an
ability to retain agro-chemicals. Soil contamination causes the
presence of xenobiotic chemicals and very varied from
industrial activity, improper disposal of waste to agricultural
chemicals. The presence of pesticide compounds in soils may
have different sources: direct application, accidental spillage,
runoff from the surface of plants, or from incorporation of
pesticide contaminated plant materials
(Rashid et al. 2010)
.
Agricultural soil is a high value component, so its irreversible
degradation should be avoided to guarantee its fertility and
current and future value.
Soil is a complex and heterogeneous matrix with a porous
structure that contains both inorganic (variable percentage of
sand, silt, and clay) and natural organic components mainly
composed by humic substances (10–15%), lipids,
carbohydrates, lignin, flavonoids, pigments, resins and fulvic acids
(Pinto et al. 2011)
. These compounds are characterized by
the diverse chemical structure and physicochemical
properties, which cause many analytical problems. Therefore,
pesticide analysis at low concentration levels in these samples is a
very difficult and challenging task.
In the literature, the analytical procedures for the
determination of pesticide residues in soil commonly are based on
traditional sample preparation methods, such as: liquid solid
(LSE) (
Durović et al. 2012
), solid phase extraction (SPE)
(Dąbrowska et al. 2003)
, ultrasonication in acetone
(Harrison et al. 2013)
, and in soxhlet apparatus extraction
(Sanghi and Kannamkumarath 2004)
. Other methods, such
as accelerated solvent (ASE) (
Rouvière et al. 2012
), dispersive
liquid-liquid microextraction (DLLME)
(Pastor-Belda et al.
2015)
, matrix solid phase dispersion (MSPD) (Łozowicka
et al. 2012), ultrasonic solvent (USE)
(Tor et al. 2006)
,
microwave assisted (MAE)
(Guo and Lee 2013; Fuentes et al.
2007)
, pressurized liquid (PLE) (Martinez Vidal et al. 2010;
Masiá et al. 2015), solid phase microextraction (SPME)
(Moreno et al. 2006)
, supercritical fluid extraction (SFE)
(Naeeni et al. 2011)
have been developed to reduce the
amount of reagents and time provided on sample preparation.
Nowadays, in pesticide residue analysis, QuEChERS
method (ang. Ouick, Easy, Cheap, Effective, Rugged and
Safe), developed by
Anastassiades et al. (2003)
, become a
very popular technique for different matrix sample
preparations such as: cereals
(He et al. 2015)
, fruit and
vegetables
(Lehotay et al. 2010)
, honey (
Bargańska et al. 2013
),
tea
(Lozano et al. 2012)
and tobacco (Łozowicka et al.
2015), because of its simplicity, low cost, amenability to
high throughput, and high efficiency with a minimal
number of steps. It involves two steps, extraction based
on partitioning between an aqueous and an organic layer
via salting-out and dispersive SPE for further cleanup
using combinations of MgSO4 and (...truncated)