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Identifier |
000394757 |
Title |
Εκτίμηση της έκθεσης σε PCBs και DDDs(πολυχλωριωμένα διφαινύλια και οργανοχλωριωμένα φυτοφάρμακα)σε δείγματα πληθυσμού Μακεδονίας,Αττικής,Πελοπονήσσου και Κρήτης με φασματομετρία μάζης (MS) και ανιχνευτή δέσμευσης ηλεκτρονίων (ECD) |
Alternative Title |
Assesment of PCBs and DDs exposure of population samples from Attica,Macedonia,Peloponessus and Crete using mass spectrometry and electron capture detection |
Author
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Μπαρμπούνης, Εμμανουήλ Γ
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Thesis advisor
|
Τσατσάκης. Αριστείδης
|
Reviewer
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Τσακάλωφ, Ανδρέας
Μαχαιρά, Κυριακή
Ρίζος, Απόστολος
Τζανακάκης, Γεώργιος
Ψυλλάκη, Ελευθερία
|
Abstract |
Human exposure to persistent organic pollutants (POPs) assessment is
crucial for public health protection and risk assessment. Hair sample is a
suitable and important medium for monitoring and evaluation of exposure to
drugs or to chemical substances. The idea of using human hair as an indicator
in assessing exposure to persistent organic pollutants (POPs) has been
advancing for the last two decades. One of the reasons for the late
development of environmental biomonitoring using human hair as a matrix is
the low detection limits which need to be achieved.
PCBs and DDTs are some of the most known POPs. They are resistant to
biological and chemical degradation and have long environmental half-lives.
Both DDTs and PCBs accumulate in the food chain, in human and animal
tissues. The biomonitoring of DDTs and PCBs for the estimation of human
exposure requires complex sample preparation and analytical procedures
using sensitive state-of-the-art instrumentation to achieve the desired
selectivity and quantification limits.
The purpose of this study was to determine PCBs and DDTs in hair samples
using precise and accurate methods. Polychlorinated biphenyls (PCBs) and
1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane) (DDT) levels were determined
in human hair samples, originating from urban and rural regions of Greece, by
gas chromatography–mass spectrometry (GC–MS) and gas chromatography–
double focusing high resolution mass spectrometry (GC–DFHRMS) using
solid–liquid extraction and headspace solid phase microextraction (HSSPME)
technique.
Polychlorinated biphenyls (PCBs) levels were assessed in human hair
samples, originating from two main agricultural regions of Greece. The
analysis was performed by gas chromatography–mass spectrometry (GC–
MS) and gas chromatography–double focusing high resolution mass
spectrometry (GC–DFHRMS). The main analytical procedure involved hair
decontamination, solid–liquid extraction and cleanup steps. The recoveries of
PCBs ranged from 71.2% to 101.6%, with accuracies greater than 87.5% and
the between run precisions (%RSD) lower than 25% for all analytes.
Differences in the frequencies of detection and the median values of PCBs
were detected between the examined regions and between the applied
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analytical techniques. All Peloponnesus’ hair examined samples were found
positive for each examined PCB, while the percentage of the total positive
samples ranged from 86.1% (for PCB 138) to 94.4% (for PCB 28 and 153
congeners) using GC–DFHRMS. The Cretan hair samples were less
contaminated (SUM PCBs = 0.61 and 1.47 pg/mg) unlike the Peloponnesus’
samples (SUM PCBs = 24.68 and 38.74 pg/mg) measured by GC–DFHRMS
and GC–MS, respectively. PCBs with high chlorination gave lower
concentration values compared to low chlorination PCBs in both populations.
No significant differences were observed between women and men. The GC–
DFHRMS technique provided higher percentage of positive samples and low
PCBs median values, due to higher sensitivity and interferences from isobaric
ions in the GC–MS technique and is therefore considered as a powerful tool
for such assessments in hair specimens.
Furthermore, headspace solid phase microextraction (HSSPME) technique
was to developed as a rapid and cost efficient hair extraction method for the
simultaneous determination and biomonitoring of 1,1,1-trichloro-2,2-bis (4-
chlorophenyl)ethane) (DDT) and its isomers/metabolites and polychlorinated
biphenyls (PCBs) in hair samples. A total of 72 head hair samples were
collected from children living in urban and rural regions of the island of Crete.
Two hundred milligrams of hair were digested under alkaline conditions and
thermostated for 30min at 90°C while a 65 μm PDMS/DVB fibre was exposed
into the headspace of the vial. Analytical parameters of the method (time of
incubation, agitation speed, recovery, precision, accuracy, carry over, matrix
effect, linearity, and selectivity) were examined. Recoveries of the DDTs in the
spiked hair samples were calculated from 42.3% for opDDD to 87.1% for
opDDE, while recoveries for PCB congeners were from 52.6% for PCB138 to
96.6 % for PCB28. The method was applied for the analysis of authentic hair
samples. Significant differences (p=0.001) of the burden to total DDTs
(sumDDTs) as well as of the frequencies of detection of positive samples
(p=0.020) were observed between the examined regions. Moreover,
significant differences in the detected concentrations of PCB congeners were
observed for PCB52 (p<0.001) and PCB28 (p=0.017) as well for their
prevalence between urban and rural regions. Application of HSSPME for the
biomonitoring of DDTs and PCBs biomarkers in hair was tested and
successfully applied to the analysis of spiked and authentic hair samples.
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HSSPME was found to be substantially simpler and faster procedure than
previous reported sample treatment procedures.
Summarizing, all methods proved to be both accurate and precise since all
recoveries obtained were higher than 42% and %relative standard deviation
values lower than 25%. The GC–DFHRMS technique gave higher sensitivity
and provided less interferences from isobaric compared to the GC–MS
technique and was therefore considered as a powerful tool for such
assessments in hair specimens. Furthermore, HSSPME was found to be
substantially simpler and faster procedure than previous reported sample
treatment procedures Finally, all Peloponnesus’ hair examined samples were
found positive for each examined PCB whereas the the Cretan hair samples
were less contaminated (PCBs with high chlorination gave lower
concentration values compared to low chlorination PCBs in both populations.
No significant differences were observed between women and men.
|
Language |
Greek |
Subject |
Gas chromatography-double focusing high resolution mass spectrometry |
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Gas chromatography-mass spectrometry |
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Hair samples |
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Headspace solod phase microextraction |
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Polychlorinated biphenyls |
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Αεριοχρωματογραφία με ανιχνευτή φασματομετρίας μαζών |
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Αεριοχρωματογραφίας διπλής εστίασης υψηλής διακρισιμότητας με ανιχνευτή φασματομετρίας μαζών |
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Δείγματα τρίχας |
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Μικροεκχύλισης στερεάς φάσης υπερκείμενης φάσης |
Issue date |
2015-07-17 |
Collection
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School/Department--School of Medicine--Department of Medicine--Doctoral theses
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Type of Work--Doctoral theses
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Permanent Link |
https://elocus.lib.uoc.gr//dlib/9/d/7/metadata-dlib-1435141267-816806-28244.tkl
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Views |
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