© Benaki Phytopathological Institute
Neonicotinoids Biomonitoring: A review
35
ments such as air (Dockery and Pope, 1994;
Chen and Liao, 2006). Amongst the organ-
ic pollutants that impact the environment,
pesticides possess a predominant role. In-
creasing number of works and modern ap-
plications are published in the domain of
presence of pesticides in human biological
fluids [see (Hernandez
et al
., 2005; Inoue
et
al
., 2007; Jia
et al
., 2008)]. The latter are often
encompassed in prospective cohort studies
that try to elucidate diseases’ causes and as-
sociate them with chemicals’ exposure. Such
studies have proved their efficacy to un-
veil important aspects of prenatal exposure
(Bouchard
et al
., 2011; Engel
et al
., 2007).
Human biomonitoring is a leading field
in bioanalysis, which covers all parts of the
analysis of contaminants in biological flu-
ids such as urine, blood, serum, saliva and
body tissues. Amongst all matrices (invasive
and non-invasive), blood and urine are the
most frequently investigated. The collection
of biomonitoring data regarding pesticides
is of great interest since human exposure is
portrayed, and association of concentration
levels with potential toxicological effects is
plausible.
Gagliardi and Pettigrove (2013) report-
ed the improvement of aquatic ecosystem
health after removal of intensive agriculture
from an Australian region. Similarly, minimi-
zation of pesticides’ use should be sought
projecting in lowered residue levels found
in human biological fluids and tissues and
subsequently less impact on human health.
Given this aspect, NNDs should be encom-
passed in monitoring schemes, and collec-
tion of pertinent works is of primary impor-
tance.
The present review summarizes all de-
velopments in the field of determination of
NNDs and metabolites in human biological
fluids. To our knowledge, all available works
are included, and highlights of each one are
discussed. In addition, case reports are pre-
sented that in some cases contain analyti-
cal approaches. In the same context, future
prospects are provided with emphasis on
the directions towards pertinent research
endeavors should be focused.
Bioanalytical Methods
A biomonitoring study comprises a
study population, data and biospecimen
collection, sample preparation and purifi-
cation, and finally chemical analysis. A fun-
damental prerequisite for a human biomon-
itoring study is to obtain information from
the target population group regarding pos-
sible exposure to particular pollutants. By
this way, the analytical methods become
focused, and results more easily interpret-
ed and related to possible health prob-
lems that might emerge. However, biologi-
cal fluids are complex materials that contain
macromolecules such as proteins, and oth-
er organic compounds that share common
physicochemical parameters with the an-
alytes of interest. Thus, the sample prepa-
ration step is also critical in providing pure
samples, enriched in analytes consider-
ing that compounds of interest are usual-
ly found at low concentrations. Exceptions
are the intoxication incidents in which lev-
els are usually higher. One of the most com-
mon sample preparation techniques is liq-
uid-liquid extraction (LLE) (Kataoka, 2003).
It works through the extraction of analytes
from the matrix using an organic solvent. Its
traditional form has certain downsides that
are observed in some occasions, such as the
non-miscibility of solvents with the sam-
ples, and their difficulty in extracting polar
and ionic compounds from aqueous media.
Advances on LLE and several of its modified
protocols have gained ground the last two
decades and are extensively used in analy-
sis of contaminants in various commodities
(Bosch-Ojeda and Sanchez-Rojas, 2009; de
Pinho
et al
., 2010). Another routine approach
in the sample preparation is solid phase ex-
traction (SPE). SPE has been broadly used in
preparing the analysis of pesticides in bio-
logical fluids (Kataoka, 2003). It possesses
certain advantages, such as high recovery,
enrichment of analytes through pre-con-
centration, relatively short preparation time,
and automation compatibility (Li, 2013; Li
et
al
., 2013; Togola
et al
., 2014). Last but not
least, protein precipitation is of the oldest
ways of processing samples in bioanalysis. It
