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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

Μπαρμπούνης, Εμμανουήλ Γ

Thesis advisor

Τσατσάκης. Αριστείδης

Reviewer

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 10 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. 11 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

Gas chromatography-mass spectrometry

Hair samples

Headspace solod phase microextraction

Polychlorinated biphenyls

Αεριοχρωματογραφία με ανιχνευτή φασματομετρίας μαζών

Αεριοχρωματογραφίας διπλής εστίασης υψηλής διακρισιμότητας με ανιχνευτή φασματομετρίας μαζών

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