High performance liquid chromatographic determination of alcohols with reference to body distribution of methanol.

A method has been developed on reverse phase high performance liquid chromatography for simultaneous determination of methyl, ethyl and isopropyl alcohols under refractive index detection using pure water as the mobile phase. A good separation has been achieved between these alcohols. Detector response was linear with a detection limit of 5 mg/100 ml. Recovery studies were performed by adding known amounts of methyl and ethyl alcohols to blood, lung and liver within the range 80-90%. The reproducibility of the results was always greater than 90%. The quantitative distribution of methyl alcohol in postmortem body tissues and fluids has been reported in three cases of poisoning.     

Rapid Separation of Organophosphate Pesticides using Micellar Electrokinetic Chromatography and Short‐end Injection,

Organophosphate (OP) pesticides are highly toxic substances and are frequently represented as poisons. In order to qualify and quantify the selected OP pesticides (methyl paraoxon, ethyl paraoxon, methyl parathion, fenitrothion, and ethyl parathion), micellar electrokinetic chromatography and short‐end injection were investigated. This is the first time that this combination has been used to separate OP pesticides. A capillary with 8.5 cm effective length was used, and the analytes were separated within 2.1 min. Separation conditions including buffer (type, pH, and concentration), sodium dodecyl sulfate concentration, and separation voltage were optimized. The limit of detection (LOD) was estimated in the range of 10–20 μM. The OP pesticides spiked in artificial saliva and drinking water gave superior peak profiles, and good average recoveries 95.6% and 62.3%, respectively. Overall, a rapid method with excellent resolution and efficiency was developed and successfully applied in the analysis of potential sample matrixes.     

Unified gas chromatography method for the detection of volatile toxicants in biological samples

A method was designed to identify and quantify the volatile toxicants in cadaveric samples; it is based on analyzing the equilibrium of the gas-vapor phase. A system comprising 3 gas chromatography columns with different polarities and without preliminary isolation of an analyzed substance is used in toxicants' identification. 0.2% n-propanol solution was used in quantification of fresh biological samples, while methanol solution was used in cases of purulence-affected materials. The method sensitivity provides for detecting some of the toxicants, like acetaldehydes, acetone as well as ethyl and higher alcohols at the level of their natural content. The method has been tested for as long as 15 years at expertise objects.     

Confirmation by LC–MS of drugs in oral fluid obtained from roadside testing

The aim of this study was to assess the effectiveness of two current on-site oral fluid (OF) drug detection devices (OraLab and Dräger), as part of the Spanish participation in the Roadside Testing Assessment Project (ROSITA Project). The study was done in collaboration with the Spanish Traffic Police, in Galicia (NW Spain), during 2004 and 2005. A total of 468 drivers selected at the police controls agreed to participate through informed consent. In addition, saliva samples were collected and sent to the laboratory to confirm the on-site results. For this purpose, two different analytical liquid chromatography–mass spectrometry (LC–MS) methods were used to detect 11 drugs or metabolites in a 300 μL sample. Simultaneous analysis of morphine, 6-acetylmorphine, amphetamine, methamphetamine, MDA, MDMA, MDEA, MBDB, cocaine and benzoylecgonine was carried out using 100 μL of oral fluid, after an automated solid phase extraction. A different LC–MS method was performed to detect Δ⁹-THC in 200 μL of oral fluid using liquid–liquid extraction with hexane at pH 6. Both methods were fully validated, including linearity (1–250 ng/mL, 2–250 ng/mL) recovery (>50%), within-day and between-day precision (CV < 15%), accuracy (mean relative error < 15%), limit of detection (0.5 and 1 ng/mL), quantitation (1 and 2 ng/mL) and matrix effect. All of the positive cases and a random selection of 30% of the negatives were analyzed for confirmation analysis. Good results (sensitivity, specificity, accuracy, positive predictive value and negative predictive value > 90%) were obtained for cocaine and opiates by OraLab, and for cocaine by Dräger. However, the results for the other compounds could be improved for both detection devices. Differences in the ease of use and in the interpretation mode (visual or instrumental) were observed.     

The GC–MS detection and characterization of reticuline as a marker of opium use

Reticuline (a precursor of opium alkaloids) was detected and characterised as its trimethylsilyl ethers, acetyl esters and methyl ethers by GC–EIMS and GC–CIMS in opium and the urine of opium users after hydrolysis by acid or β-glucuronidase as coextractive of morphine. Because this compound cannot be detected in heroin and poppy seeds, it is suggested as a differentiating marker between opium and heroin use, opium and poppy seeds use, or opium and “pharmaceutical” codeine use in cases when opiate use has been confirmed by detection of morphine and codeine in the urine. As well as being a constituent of opium, reticuline in the urine of opium users may also result from the metabolic demethylation of the three other benzyltetrahydroisoquinoline opium alkaloids: codamine, laudanosine and laudanine.     

Carbohydrate-deficient transferrin (CDT): A reliable indicator of the risk of driving under the influence of alcohol when determined by capillary electrophoresis

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 200 nm. 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 χ²-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.     

Desorption electrospray tandem MS (DESI-MSMS) analysis of methyl centralite and ethyl centralite as gunshot residues on skin and other surfaces

Abstract:  A direct and sensitive method for the detection of methyl centralite (MC) and ethyl centralite (EC) as gunshot residues (GSRs) has been developed. This method uses desorption electrospray ionization (DESI)-tandem mass spectrometry and directly desorbs and detects analytes from surfaces without any sampling process. Typical transitions for MC and EC, m/z 241 to m/z 134 and m/z 269 to m/z 148, respectively, were used to improve the assay sensitivity. It has been shown that MC and EC can be detected on various surfaces, with detection limits of 5–70 pg/cm². Interferences, detection time after shooting and the number of times hands were washed after shooting were also evaluated. None of the materials interfered with the results and the detection window for organic GSRs was up to 12 h and hands could be washed at least six times. Further samples were analyzed to confirm the reliability of this method, and showed that it could discriminate shooters from nonshooters. This method should be of significance in forensic science, especially in analyzing GSRs, because of its simplicity, high throughput, and the direct detection of MC and EC on suspects' hands, clothes, and hair.     

Simultaneous analysis of six amphetamines and analogues in hair, blood and urine by LC-ESI-MS/MS: Application to the determination of MDMA after low Ecstasy intake

A rapid and sensitive method using LC-MS/MS triple stage quadrupole for the determination of traces of amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA, “ecstasy”), 3,4-methylenedioxyethamphetamine (MDEA), and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB) in hair, blood and urine has been developed and validated. Chromatography was carried out on an Uptisphere ODB C₁₈ 5 μm, 2.1 mm × 150 mm column (Interchim, France) with a gradient of acetonitrile and formate 2 mM pH 3.0 buffer. Urine and blood were extracted with Toxitube A^® (Varian, France). Segmented scalp hair was treated by incubation 15 min at 80 °C in NaOH 1 M before liquid–liquid extraction with hexane/ethyl acetate (2/1, v/v). The limits of quantification (LOQ) in blood and urine were at 0.1 ng/mL for all analytes. In hair, LOQ was <5 pg/mg for MA, MDMA, MDEA and MBDB, at 14.7 pg/mg for AP and 15.7 pg/mg for MDA. Calibration curves were linear in the range 0.1–50 ng/mL in blood and urine; in the range 5–500 pg/mg for MA, MDMA, MDEA and MBDB, and 20–500 pg/mg for AP and MDA. Inter-day precisions were <13% for all analytes in all matrices. Accuracy was <20% in blood and urine at 1 and 50 ng/mL and <10% in hair at 20 and 250 pg/mg. This method was applied to the determination of MDMA in a forensic case of single administration of ecstasy to a 16-year-old female without her knowledge during a party. She suffered from hyperactivity, sweating and agitation. A first sample of urine was collected a few hours after (T + 12 h) and tested positive to amphetamines by immunoassay by a clinical laboratory. Blood and urine were sampled for forensic purposes at day 8 (D + 8) and scalp hair at day 60 (D + 60). No MDMA was detected in blood, but urine and hair were tested positive, respectively at 0.42 ng/mL and at 22 pg/mg in hair only in the segment corresponding to the period of the offence, while no MDA was detectable. This method allows the detection of MDMA up to 8 days in urine after single intake.     

The Fatal Poisoning Pattern of Ankara (Turkey) and Nearby Cities from 2007 to June 2011: A Retrospective Study in Forensic Autopsies

We aimed to obtain an outline of the nature and number of fatal poisonings which still appear to affect widely the population in Turkey. A total of 5921 forensic autopsies were performed between 2007 and 2011 in Ankara and nearby cities and 366 of them were fatal poisonings (219 male, 147 female). Most of the cases were between 41 and 60 years old (n = 84). Most of the fatalities were reported during winter months (48.1%). Carbon monoxide exposure was the most common reason (66.7%) within all the causes followed by medicine and narcotics (13.9%). Postmortem blood alcohol concentrations in ethyl and methyl alcohol poisonings were 385.1 ± 61.9 and 206.8 ± 138.9 mg/dL, respectively. The most common location of deaths was home (71.3%). Fatal poisonings have been a growing global problem because of some shortcomings about the socioeconomic conditions and increasing illicit drug abuse. The level of education, socioeconomic conditions, and legal approaches are very important for the prevention fatal poisonings.     

Fatal intoxication with tianeptine (Stablon)

Tianeptine (Stablon^®), although structurally similar to tricyclic antidepressants, acts by enhancing the reuptake of serotonin. A fatal case is presented involving a 26-year-old man, found lying in bed with a “mushroom of foam” around his mouth. Empty blister packs of Stablon^® and a suicide note were found next to the body. A liquid–liquid extraction procedure with n-hexane: ethyl acetate and n-hexane: 2-propanol, followed by LC-DAD-MS analysis, using positive mode electrospray ionization was performed. The detection limit was 0.001 μg/mL. The toxicological results revealed the following tianeptine concentrations in the post-mortem samples: blood 5.1 μg/mL; urine 2.0 μg/mL; liver 23 μg/g; stomach contents 22 mg. Femoral blood analyses also revealed an ethanol concentration of 0.53 g/L. The present method was also developed and validated for the other post-mortem specimens, since no previous published data had confirmed the post-mortem distribution of tianeptine. The absence of other suitable direct causes of death (macroscopic or histological) and the positive results achieved with the toxicological analysis led the pathologist to rule that death was due to an intoxication caused by the suicidal ingestion of tianeptine in combination with alcohol.     

肝中对硫磷的固相萃取—电子捕获检测气相色谱分析法

目的建立肝中对硫磷的快速、灵敏、可靠的GC／ECD分析方法。方法肝匀浆加内标甲基对硫磷,用乙腈浸提,浸提液加6％高氯酸稀释,稀释的上清液用GDX403树脂进行固相提取,提取物用HP-5色谱柱和电子捕获检测器进行气相色谱分析。结果提取率92.3％,检测限7.8ng／g,线性范围0.04～4.0μg／g,回收率99.6％±6.2％(Mean±CV,n=5)。结论方法简便、灵敏适合于实际案件检验。     

Determination of MDMA, MDA, MDEA and MBDB in oral fluid using high performance liquid chromatography with native fluorescence detection

This paper describes the analytical methodology for the determination of MDMA, MDA, MDEA and MBDB in oral fluid. After a liquid–liquid extraction, the analysis was carried out by high performance liquid chromatography (HPLC), with fluorescence detection. The detector wavelength was fixed at 285 nm for excitation and 320 nm for emission. The mobile phase, a mixture of phosphate buffer (pH = 5) and acetonitrile (75:25), and the column, Kromasil 100 C8 5 μm 250 mm × 4.6 mm, allowed good separation of the compounds in an isocratic mode in only 10 min. The method was validated and showed good limits of detection (2 ng/mL) and quantitation (10 ng/mL) for all the amphetamine derivatives. No interfering substances were detected. A stability study of these compounds in oral fluid stored at three different temperatures (−18, 4 and 20 °C) over 10 weeks was conducted, showing a time-dependent degradation of the four compounds.     

Tropane ethyl esters in illicit cocaine: isolation, detection, and determination of new manufacturing by-products from the clandestine purification of crude cocaine base with ethanol

Seven ethyl homologues of known tropane esters have recently been detected as impurities in the gas chromatographic signature profiles of authentic Peruvian illicit cocaine base and hydrochloride exhibits. Peruvian cocaine base processors are now known to use ethanol for the purification of crude cocaine base. This process is referred to as the "base lavada" or "washed base" process and is a recent substitute method for the potassium permanganate oxidation purification methodology. Seven ethyl ester homologues were formed in illicit cocaine from the transesterification of known tropane methyl esters or possibly ethyl esterification of their respective tropane C-2 carboxylic acids in the presence of ethanol. Exhibits containing these compounds were subjected to gas chromatographic-mass spectrometric analyses to determine their identity and were subsequently synthesized to verify their structures. Quantitative determinations were obtained from ion-pair chromatography isolation followed by gas chromatography with flame ionization detection. Specifically, hexanoylecgonine ethyl ester, cocaethylene, cis-cinnamoylecgonine ethyl ester, trans-cinnamoylecgonine ethyl ester, 3',4',5'-trimethoxybenzoylecgonine ethyl ester, cis-3',4',5'-trimethoxycinnamoylecgonine ethyl ester, and trans-3',4',5'-trimethoxycinnamoylecgonine ethyl ester were detected and characterized. When present, these compounds were detected at levels ranging from 8.6 x 10(-4) to 9.3 x 10(-1)% relative to cocaine.     

Improved method for the detection of TATP after explosion

TATP in post explosion exhibits was reported earlier to be best recovered from vapor phase. A typical procedure includes its adsorption on Amberlite XAD-7, elution with acetonitrile and analysis by GC/MS. In this work, improved recovery of TATP from the vapor phase was achieved by SPME using PDMS/DVB fiber and immediate sampling to GC/MS. The recovery of TATP by SPME was compared with headspace and with adsorption on Amberlite XAD-7 by spiking onto filter paper put in a 100 mL beaker. The limit of detection of TATP was 6.4 ng in these conditions, few orders magnitude more than in the other tested methods. Recovery of TATP in the presence of various solvents was also studied. Acetone, water, and mixtures of water:alcohols (1:1) were found to reduce the recovery of TATP. Using SPME, TATP has been identified in dozens of post-explosion cases.     

Application of solvent microextraction to the analysis of amphetamines and phencyclidine in urine

A fast and simple method to detect some commonly abused illicit drugs, amphetamine, methamphetamine, 3,4-methylendioxy-amphetamine (MDA), 3,4-methylendioxy-methamphetamine (MDMA), 3,4-methylendioxy-N-ethylamphetamine (MDEA) and phencyclidine (PCP) in urine using solvent microextraction (SME) combined with gas chromatography (GC) analysis has been developed. The extraction is conducted by suspending a 2 μl drop of chloroform in a 2 ml urine sample. Following 8 min of extraction, the organic solvent is withdrawn into the syringe and injected into a GC with a pulsed discharge helium ionization detector (PDHID).The effects of different extraction solvents and times, pH and sample preparation were studied. The optimized method was capable of detecting drugs in urine at concentrations below Substance Abuse and Mental Health Services Administration (SAMHSA) established cut-off values for preliminary testing. Good linearity and reproducibility of extraction were obtained. The limits of detection were 0.5 μg/ml for amphetamine, 0.1 μg/ml for methamphetamine and MDA, 0.05 μg/ml for MDMA, 0.025 μg/ml for MDEA and 0.015 μg/ml for PCP. Relative standard deviation (R.S.D.) values ranged between 5 and 20% for the studied drugs.     

Arsenic speciation of two specimens of Napoleon's hair

Since 1960, it has been demonstrated by various analytical procedures that high concentrations of arsenic were present in Napoleon's hair. Various authors, indicating that the detected arsenic levels are a consequence of external contamination, have challenged the results of these examinations. We have tested two strands of hair, referenced as Noverraz and Grand Maréchal Bertrand. Samples were incubated 6 h in water at 90 °C, and arsenic speciation was carried out by HPLC–ICP/MS. The residue was injected on a cation-exchange PRP-X200 column that allows the detection of arsenobetaine and on an anion-exchange PRP-X100 column to test for the mineral forms. In these conditions, the inorganic species As(III), As(V) and their metabolites (DMA and MMA) were separated. Analysis of hair samples highlighted massive amounts of total arsenic (42.1 and 37.4 ng/mg). Arsenical species found in the two samples of analyzed hair are distributed in the following: As(III) 31.1 and 44.7%; As(V) 66.3 and 53.2%; DMA 0.42 and 0.15%. Traces of MMA were detected, and 2% of the species could not be identified. These results prove that more than 97% of the arsenic found in the hair of Napoleon is in inorganic form, which is consistent with a chronic intoxication to arsenic.     

Oral fluid collection: The neglected variable in oral fluid testing

The potential to use oral fluid as a drug-testing specimen has been the subject of considerable scientific interest. The ease with which specimens can be collected and the potential for oral fluid (OF) drug concentrations to reflect blood–drug concentrations make it a potentially valuable specimen in clinical as well as forensic settings. However, the possible effects of the OF collection process on drug detection and quantification has often been over looked. Several studies have documented that drug-contamination of the oral cavity may skew oral fluid/blood drug ratios and confound interpretation when drugs are smoked, insufflated or ingested orally. OF pH is predicted to have an effect on the concentration of drugs in OF. However, in a controlled clinical study, the effect of pH was less than that of collection technique. Mean codeine OF concentrations in specimens collected a non-stimulating control method were 3.6 times higher than those in OF collected after acidic stimulation. Mean codeine concentrations were 50% lower than control using mechanical stimulation and 77% of control using commercial collection devices.Several factors should be considered if a commercial OF collection device is used. In vitro collection experiments demonstrated that the mean collection volume varied between devices from 0.82 to 1.86 mL. The percentage of the collected volume that could be recovered from the device varied from 18% to 83%. In vitro experiments demonstrated considerable variation in the recovery of amphetamines (16–59%), opiates (33–50%), cocaine and benzoylecgonine (61–97%), carboxy-THC (0–53%) and PCP (9–56%). Less variation in collection volume, volume recovered and drug recovery was observed intra-device. The THC stability was evaluated in a common commercial collection protocol. Samples in the collection buffer were relatively stable for 6 weeks when stored frozen. However, stability was marginal under refrigerated conditions and poor at room temperature. Very little has been published on the efficacy of using IgG concentration, or any other endogenous marker, as a measure of OF specimen validity. Preliminary rinsing experiments with moderate (50 mL and 2 × 50 mL) volumes of water did not reduce the OF IgG concentration below proposed specimen validity criteria. In summary, obvious and more subtle variables in the OF collection may have pronounced effects on OF–drug concentrations. This has rarely been acknowledged in the literature, but should to be considered in OF drug testing, interpretation of OF–drug results and future research studies.     

Voltammetric determination of cocaine in confiscated samples using a cobalt hexacyanoferrate film-modified electrode

In this work, a fast, non destructive voltammetric method for cocaine detection in acetonitrile medium using a platinum disk electrode chemically modified with cobalt-hexacyanoferrate (CoHCFe) film is described. The deposition of CoHCFe film at platinum disk (working electrode) was carried out in aqueous solution containing NaClO₄ at 0.1 mol L⁻¹ as supporting electrolite. Stability studies of the film and subsequent voltammetric analysis of cocaine were made in acetonitrile medium with NaClO₄ at 0.1 mol L⁻¹ as supporting electrolite. A reversible interaction between cocaine and CoHCFe at the film produces a proportional decrease of original peak current, due to the formation of a complex between cocaine and cobalt íons, with subsequent partial passivation of the film surface, being the intensity of current decrease used as analytical signal for cocaine. A linear dependence of cocaine detection was carried out in the range from 2.4 × 10⁻⁴ to 1.5 × 10⁻³ mol L⁻¹, with a linear correlation coefficient of 0.994 and a detection limit of 1.4 × 10⁻⁴ mol L⁻¹. The analysis of confiscated samples by the proposed method indicated cocaine levels from 37% to 95% (m/m) and these results were validated by comparison to HPLC technique, being obtained good correlation between both methods.     

The forensic analysis of thermal transfer printing

Thermal transfer printing refers to printing processes that utilize heat to produce an image by either physical or chemical means or by a combination of both. As the technology has improved and the supplies have become less expensive, the use of thermal printing in the personal and business markets has increased significantly. Specifically, dye diffusion thermal transfer and thermal mass transfer have become predominant in the production of counterfeit credit cards, drivers' licenses, and other types of documents produced on plastic media. Chemical analysis by means of thin layer chromatography (TLC) has proven to be useful in characterizing various types of inks (e.g., writing and inkjet inks). In this study, the authors examined 81 different samples that included a total of 54 printer samples (43 photographic prints on paper and eleven plastic card samples) and 27 printer ribbons. A new TLC method was developed and tested utilizing a solvent system (80% n-hexane, 3% methyl ethyl ketone, and 17% ethyl acetate) that is capable of producing excellent resolution.     

A routine screening method for the major metabolite of methyl phenidate in the urine of greyhounds

A qualitative urine screening procedure for the determination of the major urinary metabolite of methyl phenidate, α-phenyl-2-piperidine acetic acid (ritalinic acid), has been devised.The method involves a salting-out extraction, conversion of the metabolite to the parent drug using methanol-hydrogen chloride, and simultaneous two-column gaschromatographic detection. Final confirmation of the presence of the drug is by two-system thin-layer chromatography. The method is suitable for the detection of illicitly administered methyl phenidate in greyhounds.