A 30 year old man was found with no signs of life in front of the house. The cyanide concentration in blood and urine was determined five years after the man\'s death. What is more, a stability study was conducted for 730 days in an authentic casework blood sample. Sample preparation procedure included precipitation with methanol:water mixture, solid phase extraction (SPE) and derivatization with the use of PFB-Br (pentafluorobenzyl bromide). The sample was analyzed using GC-QqQ-MS/MS (gas chromatopraphy coupled with tandem mass spectrometry) isotope dilution method. Separation was done using a SH-RXI-5MS column (30 m x 0.25 mm, 0.25 µm). Detection of PFB-CN and PFB-13CN was achieved using a triple-quadrupole mass spectrometer with an electron ionization (EI) ion source in multiple reaction monitoring (MRM) mode. After 5 years from the man\'s death, cyanide concentration was: 1900 ng/mL in blood and 500 ng/mL in urine. Stability study performed in an authentic blood sample 6 and 7 years after the man\'s death revealed cyanide concentrations of 1898.2 ng/mL and 1618.7 ng/mL, respectively. While spectrophotometric and colorimetric methods recorded both decrease and increase in cyanide concentration over time, newer chromatographic methods mainly indicate a decrease. The studies presented in this paper seem to confirm this trend. However, in order to interpretate the results of cyanide concentration in biological material reliably, more research is still necessary.

A gas chromatography-electron ionization-tandem mass spectrometric (GC-EI-MS/MS) method was developed and validated for determination of the major metabolites of zolpidem, zolpidem phenyl-4-carboxylic acid (ZPCA) and zolpidem 6-carboxylic acid (ZCA) in human hair. The sample preparation procedure involves decontamination, mechanical pulverization, incubation, extraction and purification prior to instrumental analysis. The extracts were derivatized using hexafluoroisopropanol and heptafluorobutyric anhydride and analyzed by GC-EI-MS/MS. The linear ranges were 8-100 pg/mg for ZPCA and 16-200 pg/mg for ZCA, with the correlation coefficients >0.997. The limits of detection were 1.8 pg/mg for ZPCA and 1.7 pg/mg for ZCA. The recoveries ranged from 77.6 to 111.7%. The intra- and inter-day precisions were within 16.9 and 11.7%, while intra- and inter-day accuracies were -7.0-8.7 and -2.8-7.8%, respectively. The developed method was applied for the analysis of forensic hair samples obtained from suspected zolpidem abusers and the following concentration ranges were monitored: ZPCA 11.9-35.9 pg/mg and ZCA 16.6-21.8 pg/mg. The method proved to be suitable for picogram-level determination of ZPCA and ZCA in human hair.

Environmental-friendly, cost-effective and fast methods were developed and validated for the analysis of seven PolyBrominated Diphenyl Ethers (PBDEs) and eight methoxylated PBDEs (MeO-PBDEs) in three distinct seafood matrices (muscle, liver and plasma) and feed using a Quick, Easy, Cheap, Efficient, Rugged and Safe (QuEChERS) extraction approach for solid samples and a Dispersive Liquid-Liquid Microextraction method (DLLME) for plasma. Instrumental analyses were performed with gas chromatography coupled to triple quadrupole mass spectrometry using electron impact source (GC-EI-MS/MS) and negative ion chemical ionization (GC-NICI-MS) to assess BDE-209. Statistical validation showed recoveries for all target substances near 100% with average Relative Standard Deviation (RSD) lower than 9% and recovery standards higher than 65% (average RSD below 20%). Average calculated Method Detection Limits (MDLs) were lower than 65 pg·g-1 wet weight (WW) for muscle, 5.35 ng·g-1 WW for liver, 4.50 ng·g-1 WW for feed, and 0.60 ng·mL-1 for plasma samples. Quality assurance and quality control practices were comprehensively described. Methods scored high in an analytical Eco-scale, thus being classified as \"an excellent green analysis\". Finally, real seafood samples collected in local markets and local fishermen were analyzed. Positive samples presented both PBDEs and MeO-PBDEs in safe amounts (0.28-125.80 ng·g-1 WW) for human consumption.

The detection of Δ9 -tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN) in hair, for the purpose of identifying cannabis consumption, is conducted in many forensic laboratories. Since external contamination of hair with these cannabis components cannot be excluded, even after hair decontamination, only the detection of THC metabolites such as 11-nor-9-carboxy-Δ9 -tetrahydrocannabinol (THC-COOH) or 11-hydroxy-Δ9 -tetrahydrocannabinol (OH-THC), is considered to prove cannabis consumption. At present, testing for THC metabolites is not standard practice due to its analytical complexity. For these reasons, we developed a novel method for the detection of THC-COOH and OH-THC as well as THC, CBD, and CBN in one single analytical run using gas chromatography-tandem mass spectrometry (GC-MS/MS) with electron ionization. After manual hair washing and grinding, sample preparation was fully automated, by means of a robotic autosampler. The hair extraction took place by digestion with sodium hydroxide. A solid-phase extraction (SPE) was chosen for sample clean-up, using a mixed-mode anion exchange sorbent. Derivatization of all analytes was by silylation. The method has been fully validated according to guidelines of the Society of Toxicological and Forensic Chemistry (GTFCh), with a limit of detection (LOD) of 0.2 pg/mg for THC-COOH and OH-THC and 2 pg/mg for THC, CBD and CBN, respectively, thus fulfilling the Society of Hair Testing (SoHT) recommendations. The validated method has been successfully applied to our routine forensic case work and a summary of data from authentic hair samples is given, as well as data from proficiency tests.

A multi-residue analytical method was developed involving co-extraction and simultaneous determination of 89 hydrophobic organic contaminants (HOCs) in marine sediments and biota using gas chromatography-electron ionization-triple quadrupole mass spectrometry (GC-EI-MS/MS) and liquid chromatography-electrospray ionization-triple quadrupole mass spectrometry (LC-ESI-MS/MS). Target analytes include polychlorinated biphenyls (PCBs), pesticides, chlorobenzenes, brominated and chlorinated flame retardants, nitro-aromatic and polycyclic musks, triclosan and methyl triclosan. Spike-recovery experiments showed relative recoveries of analytes were generally between 70% and 130%. Analyses of a sediment standard reference material (SRM 1944) demonstrated recoveries between 80% and 120% for certified concentrations of individual PCBs and pesticides. Method detection limits of individual compounds ranged from 0.1 to 57.1 pg/g dw for sediments and 0.1 to 22.8 pg/g ww for biota. A field survey of sediments and biota from Singapore\'s marine environment demonstrated the occurrence of polycyclic and nitro-aromatic musks (galaxolide, tonalide, musk ketone, etc.), halogenated flame retardants (syn- and anti-dechlorane plus (DP), α, β and γ-hexabromocyclododecane (HBCD), tetrabromobisphenol A (TBBPA), etc.), as well as triclosan and methyl triclosan. Galaxolide exhibited relatively high concentrations, with highest levels in polychaete worms (161.7±72.5 ng/g ww) and clams (546.8±220.3 ng/g ww) from mangroves. Triclosan and methyl triclosan levels were highly correlated in sediments (r(2)=0.9752), while syn- and anti-DP were strongly correlated in biota (r(2)=0.9279). anti-DP/syn-DP stereoisomer ratios were typically >1 and ranged between 0.94 and 29.2 in sediments and biota samples. γ-HBCD exhibited the highest concentrations among HBCD isomers in sediments. Conversely, α-HBCD was the dominant HBCD isomer in biota.