Lakhasly

1 Introduction
The increasing universal demand for food calls for
growing agricultural productivity, which consequently

results in widespread application of pesticides. Never-
theless, intense or timely application of pesticide ingre-
dients for agricultural purposes leads to environmental

contamination such as water and soil (Caldas et al.,
2011). Soil, which is a vital agricultural resource, has a
high capacity to store chemicals such as pesticides.
Pesticide residues which are present in surface or
groundwater have basically the potential to come into
the soil. Pesticides can go into the soil through different
pathways including (1) spraying into the soil at the stage
of germination and washing the foliage of refined plants
and (2) releasing the granules which are directly applied
onto the soil (Rial Otero et al., 2003). After being
absorbed into the soil particles, these compounds may

rapidly decompose; otherwise, if these chemicals per-
sist, they may slowly release into the atmosphere, aquat-
ic systems, and organisms.

Typically, for extracting pesticide residues from the
soil, a technique is required that can release protected
pesticides due to their interaction with soil particles.
Traditionally, the method of Soxhlet was used for
extracting pesticide residues from the soil, which was
time-consuming and solvent based (Lang et al., 2005).
This method was further replaced by environmentally

friendly approaches including ultrasonic solvent extrac-
tion (USE) (Lambropoulou & Albanis, 2004), supercrit-
ical fluid extraction (SFE) (Sun & Lee, 2003), shake-
flask approach (Dąbrowska et al., 2003), pressurized

liquid extraction (PLE) (Dagnac et al., 2005), or
microwave-assisted extraction (MAE) (Shen & Lee,

2003. 
      

      methods, occasionally followed by cleanup tech-
      niques using solid-phase extraction (SPE) (Boeuf et al.,

      
      


2004. 
      

      or solid-phase microextraction (SPME)
      (Lambropoulou & Albanis, 2004) and QuEChERS. In
      several cases, the QuEChERS method was not used for
      extracting pesticide residues present in the soil.
      In these regards, initially available studies in the
      literature were carried out in 2008 (Lesueur et al.,
      2008). Among all the analytical instruments, LC

      
      

coupled to triple-quadrupole mass spectrometry (LC-
MS/MS) using MRM mode was a compatible appropri-
ate tool for analysis of targeted pesticides in laboratories

(Alder et al., 2006; Picó et al., 2004). Herein, pesticide
residues were evaluated in soils of different regions of

northern parts of Iran (Golestan province), and the po-
tential sources and risks of contamination were identi-
fied for the first time, using QuEChERS-based extrac-
tion techniques in soil matrices along with liquid chro-
matography coupled to ESI-triple-quad mass

spectrometry (LC-MS/MS) using MRM mode. More-
over, the effect of the matrix in QuEChERS extraction

was investigated.

Table 1 demonstrates the studied pesticides belong-
ing to ten categories and their characteristics. These

compounds are widely applied in different types of
agricultural products around the world. In addition, a

few papers have been published on extraction of carba-
ryl, imidacloprid, cyproconazole, diazinon, butachlor,

krezoxim-methyl, malathion, thiophanate-methyl,
fenpropathrin, chlorpyrifos, propargite, and pinoxaden
from soil samples using QuEChERS method.