Heavy metals in edible specimens around Tagarades landfill after a big fire

The aim of this study was to provide information on the levels of heavy metals (lead and cadmium) in ed­ible specimens around the Tagarades landfill after a big fire.A total of 49 fruit, vegetable and milk samples were collected, according to the Directive 2001/22/EC. The sampling areas were: < 2.5, 2.5, 3, 4, 5, 6, 7, 8, 9 and 10 km around landfill, as well as, 35-40 km away which served as a blank area that was not affected by the landfill. Care was taken to get samples of the same varieties from different selected sites. The samples were wet digested using concentrated nitric and perchloric acid. Cadmium was analyzed using a Flame Atomic Spectrometer and lead an Atomic Absorption Spectrophotometry with graphite furnace atomization. Our results indicate that there was no apparent effect from the landfill fire on lead and cadmium levels found in the tested food samples. These specimens were safe for consumption according to the Draft Commission Regulation on Setting Maximum Limits for Certain Contaminants in Foodstuffs

Study of isolation and identification conditions of antidepressants and antipsychotic drugs in biological matrices

Sample preparation is of great significance for a successful toxicological analysis. The development of simple, effective and rapid extraction procedures of drugs from clinical or post-mortem biological samples is challenging. In the current thesis the development of efficient methods for the isolation and determination of drugs in such specimens was studied. First a Headspace-Solid Phase Microextraction (HS-SPME) procedure for the determination of venlafaxine in post-mortem biological samples by gas chromatography (GC) was developed. Venlafaxine was extracted on a 100 μm Polydimethylsiloxone (PDMS) coating SPME fiber and was determined by GC with nitrogen-phosphorous detector (NPD). HS-SPME offers significant advantages such as simplicity, low cost, compatibility with analytical systems, automation and solvent-free extraction. Salt addition, extraction temperature, preheating and extraction time were optimized to achieve high extraction recovery for venlafaxine. The developed method was simple and rapid, using HS-SPME for sample preparation prior to GC-NPD determination. Validation data was satisfactory, thus enabling application in the toxicological analysis of forensic samples. The developed protocol was applied to post-mortem biological samples of a fatally poisoned woman from venlafaxine. The drug was quantified in post-mortem blood, gastric and oesophagus contents of the deceased woman. Thereafter, the development of a LC-MS/MS method able to detect and quantify 15, most commonly prescribed antipsychotic and antidepressant drugs in blood was performed based on a quick and efficient method. QuEChERs (quick, easy, cheap, effective, rugged and safe) methodology was applied and an optimum protocol was selected after applying different conditions. The selected single-step QuEChERs protocol includes addition of acetonitrile, potassium carbonate and magnesium sulfate in 100 mL sample, stirring, centrifugation and evaporation. The method achieves satisfactory recovery of the 15 drugs of 85%, provides efficient purification of the sample from endogenous interferences, simplicity and short sample handling times. Separation of compounds was performed on a C-18 BEH Aqcuity column by Ultra High-Pressure Chromatography (UHPLC) over 11 min with gradient elution. Detection was performed by the SRM (selective reaction monitoring) technique. The method was validated and provided accurate (+ - 8%) and reproducible (6%) results in a short period of time, a critical parameter for the implementation of a trustworthy and accurate toxicological analysis. Such an approach can be useful in clinical and forensic toxicology for drug analysis in blood as drug of abuse and pharmaceuticals are chemically diverse and may benefit from multi-analyte and multi-class analysis.Στην παρούσα διατριβή πραγματοποιήθηκε η ανάπτυξη μεθόδων προσδιορισμού ψυχιατρικών φαρμάκων με σύγχρονες τεχνολογίες ανάλυσης και προκατεργασίας δείγματος. Αρχικά το ενδιαφέρον εστιάστηκε στο προσδιορισμό βενλαφαξίνης. Επιλέχθηκε η τεχνική της Μικροεκχύλιση Στερεάς Φάσης (Solid Phase Microextraction-SPME) σε συνδυασμό με την Αέρια Χρωματογραφία με ανιχνευτή αζώτου Φωσφόρου (Gas Chromatography with Nitrogen-Phosphorus Detector).Αρχικά έγινε βελτιστοποίηση των παραμέτρων ανάλυσης: συνθήκες ανάλυσης στο GC/NPD, επιλογή της κατάλληλης ίνας, του pΗ του διαλύματος, της προσθήκη άλατος, της θερμοκρασίας του θερμοστατικού λουτρού, ο χρόνος προθέρμανσης και ο χρόνος εκχύλισης. Τα αποτελέσματα καταδεικνύουν ότι η παραπάνω μέθοδος μπορεί σε ικανοποιητικό βαθμό να χρησιμοποιηθεί στην ανίχνευση και στον ποσοτικό προσδιορισμό της βενλαφαξίνης σε βιολογικά δείγματα θανατηφόρων περιστατικών (π.χ. αυτοκτονίες). Στην συνέχεια έμφαση δόθηκε στην ανάπτυξη και βελτιστοποίηση μεθόδου για τον προσδιορισμό 15 ευρέως συνταγογραφούμενων αντιψυχωτικών και αντικαταθλιπτικών φαρμάκων με υγρή χρωματογραφία σε συνδυασμό με φασματομετρία μαζών σε σειρά (LC-MS/ΜS) με στόχο την εφαρμογή της σε βιολογικά δείγματα κλινικών αλλά και νεκροτομικών περιστατικών. Μελετήθηκε η βελτιστοποίηση της ανάκτησης των φαρμάκων από ορό αίματος και μεταθανάτιο ολικό αίμα. Για την προκατεργασία εφαρμόστηκε η τεχνική QuEChERS και τα αποτελέσματα συγκρίθηκαν με την απλή μέθοδο πρωτεινικής καταβύθισης. Δοκιμάσθηκαν διαφορετικά πρωτόκολλα QuEChERS, δύο σταδίων αλλά και προσαρμοσμένα ενός σταδίου και παρουσιάζονται για πρώτη φορά αποτελέσματα απομόνωσης αυτών των φαρμάκων με προσαρμοσμένο πρωτόκολλο QuEChERS ενός βήματος. Ο διαχωρισμός των ενώσεων πραγματοποιήθηκε σε στήλη τύπου C-18 με χρωματογραφία υπερυψηλής πίεσης μέσα σε 11 min με βαθμωτή έκλουση ενώ η ανίχνευση και ποσοτικοποίηση γίνεται με την τεχνική SRM (selective reaction monitoring) σε φασματογράφο. Το βέλτιστο πρωτόκολλο προσαρμοσμένης QuEChERS ενός βήματος που περιλαμβάνει προσθήκη ακετονιτριλίου, ανθρακικού καλίου και θειικού μαγνησίου σε 100 μL δείγματος, ανάδευση, φυγοκέντριση και εξάτμιση, επιτυγχάνει ικανοποιητική ανάκτηση των 15 φαρμάκων της τάξεως του 85% και ταυτόχρονα τον ικανοποιητικό καθαρισμό του δείγματος από ενδογενείς παρεμποδίσεις, ενώ παρέχει απλότητα και σύντομους χρόνους χειρισμού του δείγματος. Επιπλέον πλεονεκτεί στους μικρούς όγκους απαιτούμενου δείγματος. Η μέθοδος ποσοτικού προσδιορισμού επικυρώθηκε και παρείχε ακριβή (+/- 8% ) και επαναλήψιμα (6% ) αποτελέσματα σε σύντομο χρονικό διάστημα, παράμετρο πολύ κρίσιμη για την εφαρμογή της σε περιστατικά που χρήζουν τοξικολογικής εξέτασης. Επιπλέον καλύπτει μεγάλο εύρος συγκεντρώσεων με δυνατότητα εφαρμογής της τόσο για την ανίχνευση υποθεραπευτικών χαμηλών συγκεντρώσεων, όσο και για τον έλεγχο τοξικών επιπέδων. Εφαρμόστηκε με επιτυχία για τον προσδιορισμό σε 13 περιστατικά για τον έλεγχο των επιπέδων των φαρμάκων σε ορό αίματος ασθενών υπό θεραπευτικό σχήμα καθώς και σε 9 περιστατικά μεταθανάτιων δειγμάτων αίματος και μπορεί να αποτελέσει αξιόπιστο και σημαντικό εργαλείο στην τοξικολογική ανάλυση

Immunoassay thechnologies for drugs of abuse testing - General principles - Recognized advantages and disadvantages

The multiple application of immunoassay technology as the «initial test» to screen for drug abuse in various biological fluids and forensic matrices is well established and regularly practiced. Immunoassay methods refer to extremely convenient and quick analytical systems that rely on specific antigen antibody reactions for drug monitoring analysis. The evolution of development and commercialization of these technologies have significantly contributed to the overall efforts in deterring and detecting the abuse of illicit substances and the misuse of various prescription medications. Generally speaking, immunoassays serve as an economic and efficient screening tool to eliminate negative specimens from further analysis and to identify the class of drugs that requires the second confirmatory step.The present article provides an overview of the fundamental principles of immunoassay methods, their general characteristics, specific limitations, various and recognized advantages and disadvantages. It describes clearly the most commonly used immunoassays for drug abuse screening, such as EMIT, RIA, FPIA and CEDIA

Non-conditioned solid-phase extraction of amphetamine from post-mortem specimens

Solid-phase extraction (SPE) procedures are being used increasingly in all types of drug testing laboratories, including those, which carry out forensic toxicological analysis. Extraction techniques are used to isolate chemical substances from biological and post-mortem substrates in order to be identified by chromatographic methods. The advantages of such procedures include decreased operation time, reduced solvent volumes and increased extraction efficiency.The present work describes a novel and faster SPE technique, without column preconditioning, for the extraction of amphetamine from spiked biological and post-mortem specimens. Abselut NEXUS columns were used for the extraction from spiked blood, bile, vitreous humour, pericardial fluid, cerebrospinal fluid, liver, brain, bone and bone marrow.The analysis of amphetamine was accomplished by gas chromatography after derivatisation with heptafluorobutyric anhydride (HFBA). The recoveries of amphetamine ranged from 78.5% (pericardial fluid) to 87.5% (bile), with relative standard deviations less than 8.0

Workplace drug testing in Northern Greece during the period 2000-2006

The aim of the present study is to present information concerning Workplace Drug Testing in Northern Greece for the period of 2000-2006, which is in continuation of previous testing. Cases included: professional drivers, individuals at pre-employment stage for security services, prostitute houses and housekeepers at prostitute houses. During the period 2000 - 2006, we handled a total of 2665 cases, each of which was examined for the presence of 5 groups of controlled substances (cannabinoids, opiates, benzodiazepines, cocaine and amphetamines). Screening was performed with Enzyme Multiplied Immunoassay Technique (EMIT), while verification of positive results and identification of substances present was achieved through chromatographic techniques.Of the 2665 cases handled in this period of 7 years, 67% concerned candidates for employment at security services, 18% concerned professional drivers, 13% concerned individuals pursuing employment at prostitute houses and 2% concerned individuals pursuing employment as housekeepers at prostitute houses.Of the total 2665 samples tested, 105 samples were positive, corresponding to 4% of the total cases. Of the controlled substances abused, cannabinoids seem to be the most popular abused drug representing 72.81% of the positive samples. Opiate abuse corresponds to 16.27% of the positive samples, cocaine abuse corresponds to 5.19% of the positive samples and benzodiazepine abuse corresponds to 5.73% of the positive samples. Finally, we noticed no cases of amphetamine abuse