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Background: Although the post-mortem increase of ammonium in biological fluids is well known, ammonium analysis in vitreous humour has never been used in recent times for the determination of the post-mortem interval. The present work represents a new application of capillary electrophoresis with indirect UV detection in the field of forensic analysis. Methods: The electrophoretic separation was carried out in a running buffer made of 5 mM imidazole, 5 mM 18-crown-6 ether and 6 mM d,l-α-hydroxybutyric acid (HIBA). To overcome the lack of optical absorption of ammonium, indirect UV detection was applied. The used wavelength was 214 nm. Results: The method showed good linearity in the concentration range from 0.16 to 5.0 mM. The limit of detection, 0.039 mmol/L, was established on the basis of the linearity curve. Precision and bias studies carried out on the pure ammonium solutions and in real biological samples, revealed %RSDs well below 20%. A preliminary application to real cases where the death time was precisely known (14 bodies) was carried out plotting vitreous humour ammonium vs. post-mortem interval with a resulting good linear correlation until 100 h post-mortem. Conclusions: After validation in real cases, the present method can become a powerful tool to unravel one of the most challenging issues of forensic investigation: determination of the time of death. [ABSTRACT FROM AUTHOR]

Abstract: Background: The determination of Carbohydrate Deficient Transferrin (CDT) in a forensic context should be based on the use of a screening technique followed, for the “positive samples”, by a confirmatory technique. The aim of this study was to compare the two most used automated screening methods for CDT analysis, immuno-nephelometric assay (INA) and multi-capillary electrophoresis (mCE), with a validated HPLC procedure, used as confirmation test, in order to re-evaluate the cut-off concentrations of the screening methods. Methods: 195 serum samples underwent CDT analysis by using the N Latex CDT direct immuno-nephelometric assay, the multicapillary system Capillarys™ and an anion exchange HPLC method with UV-visible detection at 460nm developed and validated at our laboratories. Statistical analyses were performed by using Bland–Altman plots and ROC curves. Results and discussion: The 95% limits of agreement were ±0.94% when comparing INA and HPLC and ±0.60% when comparing mCE and HPLC. The ROC analysis of both INA and mCE, using HPLC as the reference method, showed that no false negative results were found when the cut-off was fixed to 1.2% for mCE and to 2.3% for INA. Conclusions: The study showed a good agreement among CDT determinations carried out either with mCE or INA or HPLC. However, the usual cut-offs of both mCE (1.3%) and INA (2.5%) should be lowered to minimize false negatives at the screening analysis. [Copyright &y& Elsevier]

Abstract: Carbohydrate-deficient transferrin (CDT) is a marker of chronic alcohol abuse, which has recently been introduced to evaluate the physical fitness for obtaining a driving license. The aim of the present study was to evaluate the prevalence of elevated CDT levels in subjects stopped while driving under the influence of alcohol by using a validated method based on capillary electrophoresis. The study was carried out on a group of 40 drunken drivers (group A) and on a control group (n =51) of subjects chosen from the general population (group B). CDT was directly determined by capillary electrophoresis in free solution and UV detection at 200nm. CDT results from both groups were classified as “negative” or “positive” on the basis of the cut-off set at 2.00% (CDT index). The subjects classified as “positive” in group A were 24 (60%), whereas in group B were 2. The subjects classified as “negative” in group A were 16 (40%), whereas in group B was 49 (96.1%). The comparison of the observed percentages, evaluated with the χ 2-test, was highly significant (p <0.001). The present study confirms the high prevalence of chronic alcohol abusers among drunken drivers and the usefulness of CDT as a predictor of the risk of drunk driving. [Copyright &y& Elsevier]

Abstract: In forensic toxicology, hair analysis has become a well established analytical strategy to investigate retrospectively drug abuse histories. In this field, gas chromatography–mass spectrometry and high-performance liquid chromatography–mass spectrometry are currently used, often after preliminary screening with immunoassays. However, on the basis of previous applications to pharmaceutical analysis, capillary zone electrophoresis coupled to ion trap mass spectrometry looks also highly promising. The purpose of the present work was the development of a simple and rapid CZE–MS method for sensitive and quantitative determination of the main drugs of abuse and their metabolites (namely, 6-monoacetylmorphine, morphine, amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethampthetamine (MDMA), benzoylecgonine, ephedrine and cocaine) in human hair. Hair samples (100mg) were washed, cut and incubated overnight in 0.1M HCl at 45°C, then neutralized with NaOH and extracted by a liquid–liquid extraction method. CZE separations were carried out in a 100cm×75μm (I.D.) uncoated fused silica capillary. The separation buffer was composed of 25mM ammonium formate, pH 9.5; the separation voltage was 15kV. Electrokinetic injections were performed at 7kV for 30s under field amplified sample stacking conditions. ESI-ion trap MS detection was performed in the ESI positive ionization mode using the following conditions: capillary voltage 4kV, nebulizer gas (nitrogen) pressure 3psi, source temperature 150°C and drying gas (nitrogen) flow rate 8l/min. A sheath liquid, composed of isopropanol–water (50:50, v/v) with 0.5% formic acid, was delivered at a flow rate of 4μl/min. The ion trap MS operated in a selected ion monitoring mode (SIM) of positive molecular ions for each drug/metabolite. Collision induced fragmentation was also possible. Nalorphine was used as internal standard. Under the described conditions, the separation of all compounds, except amphetamine/methamphetamine, MDA/MDMA and morphine/6-MAM was achieved in 20min, with limits of detection lower than the most severe cut-offs adopted in hair analysis (i.e. 0.1ng/mg). Linearity was assessed within drug concentration ranges from 0.025 to 5ng of each analyte/mg of hair. Analytical precision was fairly acceptable with RSD''s ≤3.06% for migration times and ≤22.47% for areas in real samples, in both intra-day and day-to-day experiments. On these grounds, the described method can be proposed for rapid, selective and accurate toxicological hair analysis for both clinical and forensic purposes. [Copyright &y& Elsevier]

The present work was aimed at the development of a capillary electrophoretic analysis of γ-hydroxybutyric acid (GHB) using electrospray ion trap mass spectrometry to achieve the direct and unequivocal detection of this analyte in human urine. Optimized capillary electrophoretic conditions were: injection, 20s at 0.5psi (1 psi = 6894.76Pa); buffer electrolyte, 12.5mM ammonium formate adjusted to pH 8.35 with diethylamine; fused silica capillary: 100cm × 50μm i.d.; separation voltage, 25kV (forward polarity) + 0.5psi; room temperature. Electrospray and mass spectrometric conditions were: drying gas and nebulizing gas (nitrogen) at flow rate 3l/min, temperature 250°C, nebulizer pressure: 10psi; sheath liquid solution: methanol–water (90:10) containing 0.1% ammonia delivered at 3μl/min; spray voltage 3.5kV. Mass spetrometric detection was carried out in the selected ion monitoring mode of negative molecular ions at 103 m/z for GHB and 115 m/z for maleic acid (I.S.). Under these conditions the baseline separation of GHB and the I.S. was obtained. The selectivity of the analysis allowed for direct injection of unextracted urine, previously diluted 1:4 with water. Linearity was assessed in the GHB concentration range from 80 to 1280μg/ml in urine. Analytical sensitivity (as limit of detection) resulted about 5μg/ml in water and 20μg/ml in original urine. Analytical precision was fairly acceptable with R.S.D. values lower than 5% for migration times and 18% for quantitation in real samples, in both intra day and day-to-day experiments. On these grounds, the developed method can be adopted for rapid identification of acute intoxications from GHB in humans. [Copyright &y& Elsevier]

γ-Hydroxybutyric acid (GHB) is a central nervous system (CNS) depressant and hypnotic which, in recent times, has shown an increasing abuse either as recreational drug (due to its euphoric effects and ability to reduce inhibitions) or as doping agent (enhancer of muscle growth). Analogues of GHB, namely γ-butyrolactone (GBL) and 1,4-butanediol (1,4-BD), share its biological activity and are rapidly converted in vivo into GHB. At present, GHB and analogues are placed in the Schedules of Controlled Substances. Numerous intoxications in GHB abusers have been reported with depressive effects, seizures, coma and possibly death. The purpose of the present work was the development of a rapid analytical method based on capillary zone electrophoresis for the direct determination of GHB in human urine and serum at potentially toxic concentrations. Analytical conditions were as follows. Capillary: length 40 cm (to detector), 75 μm i.d.; buffer: 5.0 mM Na2HPO4, 15 mM sodium barbital adjusted to pH 12 with 1.0 M NaOH; voltage: 25 kV at 23 °C; indirect UV detection at 214 nm; injection by application of 0.5 psi for 5 s. α-Hydroxyisobutyric acid was used as internal standard (IS). Sample pretreatment was limited to 1:8 dilution. Under these conditions, the sensitivity was ∼3.0 μg/ml (signal-to-noise ratio >3). Calibration curves prepared in water, urine and serum were linear over concentration ranges 25–500 μg/ml with R2≥0.998. Analytical precision was fairly good with R.S.D.<0.60% (including intraday and day-to-day tests). Quantitative precision in both intraday and day-to-day experiments was also very satisfactory with R.S.D.≤4.0%. No interferences were found neither from the most common “drugs of abuse” nor from endogenous compounds. In conclusion, capillary electrophoresis can offer a rapid, precise and accurate method for GHB determination of biological fluids, which could be important for screening purposes in clinical and forensic toxicology. [Copyright &y& Elsevier]

Ketamine, traditionally available as racemic mixture, has recently become available in the form of the single S-enantiomer, due to its higher anaesthetic potency associated with faster recovery times. The different pharmaceutical forms and the different pharmacodynamics of the two enantiomers imply the need for a chiral method, since most available analytical methods for biological matrices are not enantioselective. The method herein showed consists of simple capillary zone electrophoresis (CZE) for the chiral separation of ketamine and its major metabolite, norketamine, in hair specimens. After liquid-liquid extraction, the samples were electrokinetically injected and analysed in CE (running buffer: 15mM Tris phosphate pH 2.5, containing HS-γ-CDs, 0.1%, w/v). A complete separation of both racemic ketamine and norketamine in the respective enantiomers was obtained in less than 10minutes. Limit of detection (LOD) and limit of quantification (LOQ) were 0.08ng/mg and 0.25ng/mg, respectively. Percent recovery varied from 49% to 91% for all four enantiomers. Matrix effect on spiked hair samples demonstrated values ranging from 63% to 119%. Linearity was estimated using a calibration curve consisting of five concentration levels for each enantiomer (0.5-8.0ng/mg); the regression coefficients (R(2)) of weighted (1/x(2)) linear regression were all >0.988. The method is suitable for the analysis of real-world hair samples in order to investigate ketamine chronic abuse and to discriminate between the type of abused drug, either single enantiomer or racemic drug. [ABSTRACT FROM AUTHOR]

Abstract: The coupling of capillary electrophoresis–electrospray ionization and time-of-flight mass spectrometry, combining efficiency and speed of separation with high mass accuracy and fast scanning capability, was for the first time applied to the determination of drugs of abuse (amphetamine, methamphetamine, MDA, MDMA, ephedrine, cocaine, morphine, codeine) and their metabolites in hair (6-MAM, benzoylecgonine). Experimental conditions were as follows. Separation: voltage 15kV, uncoated fused-silica capillary (75μm ID, 100cm total length), running electrolyte 25mM ammonium formate, pH 9.5, field-amplified sample stacking injection. Forensic drugs could be identified by exact mass determination (mass accuracy typically ≤ 5ppm) and by match of the isotopic pattern. The method was fully validated, showing limit of detections (LODs) suitable for the determination of all the compounds below the cut-off usually adopted for hair analysis (0.1ng/mg). Analytical precision in real matrices (tested at 0.1 and 1.0ng/mg) was typically characterized by CV''s ≤ 24% in both intra-day and day-to-day experiments. Quantitative determination was also tested by using a single internal standard (folcodine). Results, although with a moderate accuracy, conceivably depending on the lack of deuterated internal standards, proved useful for diagnostic use of the results from hair analysis. A single liquid–liquid extraction procedure was applied for all analytes, allowing the detection of a broad spectrum of basic drugs and their major metabolites. [Copyright &y& Elsevier]

Abstract: The purpose of the present work was the development and validation of a simple, rapid and reliable method for direct bromide quantification in serum based on capillary electrophoresis (CE). The analysis was carried out with an automated capillary electropherograph. Analytical conditions were as follows. Capillary: uncoated fused silica, effective length 50cm, internal diameter 50μm; voltage: 20kV in reverse polarity mode; temperature: 25°C; running buffer: 90mmol/L sodium tetraborate decahydrate and 10mmol/L NaCl, pH 9.24; detection: direct UV absorption at 200nm; sample treatment: dilution of serum 1:10 with the internal standard solution (2mmol/L thiocyanate). Under the described conditions, bromide ions and internal standard were baseline separated in 7min. No interferences from other serum components were observed. The analytical sensitivity was characterized by a LOD: 0.05mmol/L and a LOQ of 0.1mmol/L. Excellent linearity was verified in the range from 2.5 to 60mmol/L [y =0.0746x −0.0372; R 2 =0.9995 (x =bromide concentration; y =bromide peak area/internal standard (I.S.) peak area)]. Quantitative imprecision in intra-day (n =7) and day-to-day (n =7) experiments was always within R.S.D. values <2%. Recovery was quantitative throughout the range of linearity of the method. Clinical cases of infants undergoing potassium bromide therapy for refractory epilepsy were analyzed with results in agreement with literature data. On the basis of these considerations, capillary electrophoresis can be proposed as the method of choice for bromide analysis in serum samples, especially for therapeutic drug monitoring purposes. [Copyright &y& Elsevier]

Serum transferrin (Tf) comprises several isoforms with up to two complex oligosaccharide chains containing zero to eight sialic acid residues and neutral sugars. The major glycoform, known as tetrasialo-Tf, contains four sialic acid residues and accounts for about 80% of whole Tf in human serum. Carbohydrate-deficient transferrin (CDT) encompasses isoforms that are deficient in carbohydrate chains and consequently in sialic acid residues (including asialo-, monosialo- and disialo-Tf) and is a well known marker for chronic alcohol abuse. Recently capillary zone electrophoresis (CZE) has been reported as a tool extremely effective for the simultaneous, individual, quantitative determination of CDT isoforms. Three CZE methods that feature different dynamic capillary coatings were evaluated and optimized for CDT determination in human serum of alcohol abusers and control subjects. CZE separation was performed in alkaline borate buffers after serum sample saturation with iron, electropherograms were detected at 200 nm, data were evaluated as % area of disialo-Tf in relation to tetrasialo-Tf and peak identification was accomplished via relative migration times to tetrasialo-Tf, immunosubtraction and enzymatic sequential cleavage of sialic acid residues. Dynamic capillary coatings with diaminobutane, spermine and a double coating produced by commercially available proprietary agents were investigated and found to be suitable for determination of CDT in human serum. For all three approaches, best results were obtained in 50 μm I.D. fused-silica capillaries of 50 cm effective length and a capillary cartridge temperature of 20–25 °C. Using 3 mM 1,4-diaminobutane or 0.02 mM spermine in a borate-based running buffer of pH 8.3 provided data of remarkable similarity with resolution of di-, tri-, tetra- and pentasialo-Tf within 15–18 min. With the double coating, asialo-Tf and Tf isoforms with two to six sialic acid residues were baseline separated. Compared to the two amine-based procedures, the run times were found to be somewhat shorter, the detector signals higher, the applied power level significantly lower and the reproducibility better. [Copyright &y& Elsevier]

• CE-UV has been applied to the quantification of nitrite and nitrate in post-mortem specimen. • The method was applied to the quantitative determination of these ions in authentic forensic cases. • This is the first application of CE to the determination of nitrite/nitrate in fatalities. In recent years, a significant increase of reports about suicidal cases due to intentional sodium nitrite intake has been described. In the forensic pathology context, the strategy to approach intoxication cases by sodium nitrite, without any preliminary information or hint, is not straightforward. Indeed, in a number of cases the lack of crime scene data and/or specific pathological signs makes difficult the identification of nitrite poisoning. Moreover, the analytical determination of nitrite in blood is challenging, due to its rapid oxidization to nitrate by hemoglobin. Although several methods have been proposed for the clinical analysis of nitrate and/or nitrite in biological samples, none of these is specifically focused on the determination of these ions in cadaveric samples. Consequently, the diagnosis of nitrite fatal intoxication is still based on methemoglobin analysis. The present paper reports the optimization and validation of an analytical method of capillary ion analysis (CIA) with UV detection, for the determination of nitrite and nitrate in biological fluids and its application to two authentic cases of death by nitrite intake. The analyses were carried out in a bare fused-silica capillary (75 µm inner diameter) using 100 mM sodium tetraborate (pH 9.24) as background electrolyte and applying a voltage of − 15 kV between the capillary ends. The detection was obtained by direct UV absorption recorded at 214 nm wavelength. Bromide was used as the internal standard. Linearity was established in the range of 0.25–5 mmol/L). Reproducibility (intraday and day-to-day) was characterized by relative standard deviations (RSDs) 14.7% for peak areas. The method was applied to the determination of nitrite and nitrate in two real forensic cases, where high concentrations of nitrate were found in cadaveric blood samples (6.5 and 4.4 mmol/L, respectively). Nitrite was found only in trace amounts, due to the instability of this ion in cadaveric blood where it is oxidized to nitrate. The present method represents a new tool for the direct and rapid determination of nitrite and nitrate in cases of forensic interest, and thus offers a diagnostic tool more sensitive and precise than the need methemoglobin analysis. [ABSTRACT FROM AUTHOR]

Abstract Background and aim CDT is a collective biomarker including asialo- and disialo-Tf, but researchers have generally focused attention on disialo-Tf, because of its easier detectability, since asialo-Tf is typically not detectable by the current methods in abstinent individuals, social drinkers and in many alcohol abusers with moderate CDT increases. In the search of a confirmation marker of alcohol-related CDT increases, the detectability of asialo-Tf was re-evaluated comparatively by using CE vs. HPLC. Methods 468 serum samples compulsorily drawn in a forensic/administrative context were analyzed by CE and HPLC to compare their sensitivity towards asialo-Tf. Results CE allowed the identification of asialo-Tf in 108 out of 165 CDT "positive" cases, based on disialo-Tf measurement (cut-off 1.8%). HPLC showed a detectable asialo-Tf peak only in 2 cases. In addition, in some cases of disputed CDT increases, the quasi-absence of this Tf component in front of an important increase of disialo-Tf allowed the ruling out of a diagnosis of alcohol abuse, in agreement with all other clinical and laboratory data. Conclusions The present work shows a superior performance of CE vs. HPLC for the determination of asialo-Tf and the importance of this CDT component to avoid misinterpretation of non-alcohol related CDT increases. Highlights • CE and HPLC were compared in their ability to detect asialo-Tf. • CE showed a substantial prevalence over HPLC in the detection of asialo-Tf. • The results showed cases of discordant increases of disialo-Tf and asialo-Tf • In some of these cases the increase of CDT was not related with alcohol abuse [ABSTRACT FROM AUTHOR]

Background and aim The non-glycosylated glycoform of transferrin (Tf), known as asialo-Tf, was not selected (in favor of disialo-Tf) as the measurand for the standardization of carbohydrate deficient transferrin (CDT) determination because of a lower diagnostic sensitivity provided with the currently available analytical procedures for sera. However, asialo-Tf could provide an additional value to disialo-Tf in the CDT analysis employed in forensic toxicology contexts. The present work aimed at developing an easy sample preparation based on PEG precipitation in order to improve the detectability of asialo-Tf in capillary electrophoresis (CE). Methods Equal volumes (35 μL) of serum and of 30% PEG-8000 were mixed and briefly vortexed. After centrifugation, the supernatant was iron saturated with a ferric solution (1:1, v/v). The mixture was analyzed in CE for asialo-Tf and disialo-Tf determination. Results PEG-8000 precipitation allowed the improvement of the baseline in the electropherograms in terms of interferences reduction particularly in the asialo-Tf migration region. The detection of asialo-Tf was possible in 89% of samples with disialo-Tf above the cut-off limit, whereas only 16% of them showed asialo-Tf by employing the traditional sample preteatment. Conclusions Asialo-Tf represents an additional value to disialo-Tf as a biomarker of alcohol abuse in forensic toxicology. [ABSTRACT FROM AUTHOR]

Abstract: Capillary electrophoresis coupled to time-of-flight mass spectrometry was used in the present work for the determination of therapeutic and abused drugs and their metabolites in the hair of subjects undergoing addiction treatments, in order to monitor their compliance to therapy. For this purpose a rapid, qualitative drug screening method was adopted based on capillary electrophoresis hyphenated with time-of-flight mass spectrometry, which had earlier been developed and validated for the forensic-toxicological analysis of hair, limitedly to illicit/abused drugs . Sampling of hair was carried out in order to refer to a time window of about two months from the date of sampling (i.e. 2cm ca. from cortex). A single extraction procedure was applied, allowing the determination in the hair matrix of “drugs of abuse” referred to the past abuses, and therapeutic drugs prescribed in the detoxification program as well as their metabolites. Analyte identification was based on accurate mass measurements and comparison of isotope patterns, providing the most likely matching between accurate mass value and elemental formula. Small molecules (<500Da) of forensic and toxicological interest could be identified unambiguously using mass spectrometric conditions tailored to meet a mass accuracy ≤5ppm. In the present study, the proposed approach proved suitable for the rapid broad spectrum screening of hair samples, although needing further confirmation of results by using fragmentation mass spectrometry. [Copyright &y& Elsevier]

Abstract: After decades of neglect, bromide has recently been re-introduced in therapy as an effective anti-epileptic drug. The present paper describes the methodological optimization and validation of a method based on capillary zone electrophoresis for the rapid determination of bromide in serum using a high-viscosity buffer and a short capillary (10cm). The optimized running buffer was composed of 90mM sodium tetraborate, 10mM sodium chloride, pH 9.24 and 25% glycerol. The separation was carried out at 25kV at a temperature of 20°C. Detection was by direct UV absorption at 200nm wavelength. The limit of detection (signal-to-noise ratio=5) in serum was 0.017mM. The precision of the method was verified in blank serum samples spiked with bromide, obtaining intra-day and day-to-day tests, relative standard deviation values ≤0.2% in terms of migration times and values <2% in terms of peaks areas, respectively. [Copyright &y& Elsevier]

Carbohydrate deficient transferrin (CDT) is currently the most specific laboratory marker of chronic or sustained alcohol abuse. CDT is increasingly being used as a diagnostic tool in the areas employment, traffic safety and forensic medicine. In recent times, capillary electrophoresis (CE) has been proposed as a convenient tool for rapid, precise and accurate CDT determination, not only for research but also for routine analyses. Quite recently, commercial kits have been introduced which, reportedly, could simplify and standardize CDT analysis with capillary electrophoresis. The present work was aimed at testing the ruggedness of a capillary electrophoretic method based on a commercial kit (CEofix, Analis), by comparing the results obtained with different instruments in different laboratories, on a panel of sera randomly collected and exchanged. The results showed, notwithstanding few outliers, excellent correlation of the results obtained in the two laboratories (R=0.974). Also high concordance was found when results were classified as positive or negative on the basis of a cut-off (1.25%) established from a control group of teetotalers. In conclusion the present data support the usefulness of capillary electrophoresis for CDT determination for clinical, forensic and administrative diagnosis of chronic alcohol abuse. [Copyright &y& Elsevier]