A study of illicit cocaine seizure classification by pattern recognition techniques applied to metal data

Fifteen metallic species, silver (Ag), aluminum (Al), calcium (Ca), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), nickel (Ni), lead (Pb), strontium (Sr) and zinc (Zn), were determined in 46 cocaine samples confiscated by the Spanish police in Galicia (northwest Spain). Classification of these cocaine samples according to their geographic origin (Colombia and Venezuela) was achieved by the application of pattern recognition techniques to the metallic content data. Cocaine samples, around 0.5 g, were directly dissolved in 2 mL of 35.0% (v/v) HNO3, diluted to 10 mL with ultrapure water. The metals were quantified by means of electrothermal atomic absorption spectrometry (Ag, Al, Cd, Cr, Cu, Mn, Ni, Pb and Sr), flame atomic absorption spectrometry (Ca, Fe, Mg and Zn), and flame atomic emission spectrometry (K and Na). Results show that two geographic origins can be established through the presence of trace and major elements.     

The discrimination of automotive clear coats by pyrolysis-gas chromatography/mass spectrometry and comparison of samples by a chromatogram library software

Identification particles used for the purpose of the post-blast identification of explosives have a coding system based on the combination of metal oxides and their various concentrations. These materials are composed of the polymeric matrix, iron powder (ferromagnetic properties), UV light active dyestuff and various metal oxides in a various ratios. A suitable analytical method has to be used for an accurate characterization of these metal components in the particles in order to find the required information, i.e. to determine the place and the year of production and as the case may be, also the production batch of misused explosives. In this work, the method of microwave digestion and flame atomic absorption spectrometry (F-AAS) was developed for an accurate determination of Zn, Mg, Cu and Pb in a few novel types of identification particles and applied to their characterization. When using specific sample treatment (digestion with a mixture of nitric acid with hydrochloric or hydrofluoric acid), the 3 sigma limits of detection (LODs) for the determination of Zn, Mg, Cu and Pb in 5mg original samples were 1.9, 0.2, 1.3 and 2.4 mg g(-1), respectively. The signal suppression due to the presence of HNO3+HCl or HNO3+HF was observed for Zn; therefore, the calibration solutions had to be prepared exactly with the same acids as those used for the sample mineralization. The determination of Mg, Cu and Pb was free of interferences; hence a simple calibration curve method could be adopted for attaining accurate results. The accuracy was checked by comparison of the results with those obtained by means of independent inductively coupled plasma optical emission spectrometry (ICP-OES). Good precision values, as relative standard deviation, in the range of 1-5% were obtained. A total number of 71 samples was analysed and classified by multivariate methods to prove the suitability of the procedure proposed for the purpose of the identification of explosives.     

微波消解ICP/AES标准加入法测定尿液中金属毒物

目的建立微波消解ICP/AES标准加入法测定尿液中As、Ba、Pb、Cd、Cr、Zn、Sb金属毒物。方法取1.0mL尿样,加入3mL浓硝酸和0.5mL双氧水,进行微波消解。冷却后,用2%的硝酸定容至10.0mL。采用标准加入ICP/AES法进行定量分析,并优选实验条件及考察方法可靠性。结果尿液中As、Ba、Pb、Cd、Cr、Zn、Sb回收率在98.6%～104%之间;检出限在2.0～5.1ng/mL之间;线性范围Zn为5.0～200.0μg/mL,其余元素为0.5～20.0μg/mL。采用本文方法测定与国家标准物质人发和牛肝数据测定值基本一致。结论该方法回收率高、检测限低、能多元素同时测定,可以用于尿液中金属元素的检测。     

Compared interest between hair analysis and urinalysis in doping controls. Results for amphetamines, corticosteroids and anabolic steroids in racing cyclists

In France during a famous bicycle race, the newspapers documented the degree in which doping seemed to be supervised in some teams by managers and doctors. Use of anabolic steroids and other substances was officially banned in the mid-seventies by sports authorities. This policy has been enforced through urine testing before competition. It is well known, however, that a latency period is all that is necessary to defeat these tests. Nevertheless, hair analysis could be a promising tool when testing for periods that are not accessible to urinalysis any more. We have developed different sensitive methods for testing hair for amphetamines, anabolic steroids and their esters and corticosteroids. For amphetamines, 50 mg of hair were digested with 1 M NaOH, extracted with ethyl acetate, derivatized with TFA and analyzed by gas chromatography positive chemical-ionization mass spectrometry. For corticosteroids, 50 mg of powdered hair were treated with methanol in an ultrasonic bath and subsequently purified using a C18 solid phase extraction column. Analysis was realized by high performance liquid chromatography coupled to electrospray-ionization tandem mass spectrometry. For anabolic steroids and their esters, 100 mg of powdered hair were treated with methanol in an ultrasonic bath for extraction of esters, then alkaline digested with 1 M NaOH for an optimum recovery of other drugs. The two liquid preparations were subsequently extracted with ethyl acetate, pooled, then finally highly purified using a twin solid phase extraction on aminopropyl and silica cartridges. Residue was derivatized with MSTFA prior to injection. Analysis was conducted by gas chromatography coupled to a triple quadrupole mass spectrometer. Thirty cyclists were sampled and tested both in hair and in urine. Amphetamine was detected 10 times in hair (out of 19 analyses) compared to 6 times in urine (out of 30 analyses). Corticosteroids were detected 5 times in hair (methylprednisolone 1 case, triamcinolone acetonide 3 cases and hydrocortisone acetate 1 case) in hair (out of 12 analyses) compared to 12 times (triamcinolone acetonide 10 cases and betamethasone 2 cases) in urine (out of 30 analyses). Anabolic steroids were detected twice (nandrolone 1 case, and testosterone undecanoate 1 case) in hair (out of 25 analyses) compared to none in urine (out of 30 analyses).     

A survey of some metallographic etching reagents for restoration of obliterated engraved marks on aluminium-silicon alloy surfaces

A brief survey to assess the sensitivity and efficacy of some common etching reagents for revealing obliterated engraved marks on Al-Si alloy surfaces is presented. Experimental observations have recommended use of alternate swabbing of 10% NaOH and 10% HNO(3) on the obliterated surfaces for obtaining the desired results. The NaOH etchant responsible for bringing back the original marks resulted in the deposition of some dark coating that has masked the recovered marks. The coating had been well removed by dissolving it in HNO(3) containing 10-20% acid. However, the above etching procedure was not effective on aluminium (99% purity) and Al-Zn-Mg-Cu alloy surfaces. Also the two reagents (i) immersion in 10% aq. phosphoric acid and (ii) alternate swabbing of 60% HCl and 40% NaOH suggested earlier for high strength Al-Zn-Mg-Cu alloys [23] were quite ineffective on Al-Si alloys. Thus different aluminium alloys needed different etching treatments for successfully restoring the obliterated marks. Al-Si alloys used in casting find wide applications especially in the manufacture of engine blocks of motor vehicles. Hence, the results presented in this paper are of much relevance in serial number restoration problems involving this alloy.     

Accumulation of explosives in hair--part II: factors affecting sorption

This study examines the sorption of eight explosives (2,4,6-trinitrotoluene [TNT]; pentaerythritol tetranitrate [PETN]; hexahydro-1,3,5-trinitro-s-triazine [RDX]; diacetone diperoxide [DADP]; triacetone triperoxide [TATP]; ethylene glycol [EGDN], nitroglycerin [NG]; and 2,4-dinitrotoluene [DNT]) to human hair. The study uses only cut hair, which is exposed to explosive vapor. The vapor transfer studies reported herein indicated that hair did not reach saturation even after 2.5 years of exposure to TNT. While previous studies showed black hair sorbed more explosive than blond or brown, this study reports that red hair sorption is similar to black, while grey hairs, exposed along with black hair from the same individual, sorbed significantly less explosive than the same individual's black hairs. In a study using only black hair, a slight racial bias was observed with sorption greater for Mongoloid hair as compared to Caucasian or Negroid. Only for Mongoloid hairs were enough samples studied to examine for a gender bias, but one was not observed. There was much variability in results in all categories (hair color, race, and gender) that trends were established only in general terms. Hair at different ages was tested for a few individuals. Detailed studies focused on the sorption of TATP and TNT as these appear to be sorbed most differently-TATP mainly on the hair surface and TNT both on the surface and in the cortex. The uptake of high vapor pressure explosives (e.g., TATP) and moderate vapor pressure explosives (e.g., TNT) by hair was rapid and could be detected within about 1 h of exposure. Both explosives were readily sorbed by pure melanin.     

头发中氯硝西泮的分段分析在药物辅助犯罪案件中的作用

目的通过分段分析头发中的氯硝西泮,对药物辅助犯罪案件中受害人的摄药频度及摄药史进行推断。方法采用液氮冷冻研磨技术联合超声浴技术,以液相色谱-串联质谱法,对6名不同案件中受害人的头发分段分析,并测定各头发段中的氯硝西泮及7-氨基氯硝西泮的含量。结果 6名受害人的部分头发段中均检出氯硝西泮及其代谢物7-氨基氯硝西泮,且头发中药物峰值浓度的出现时间与受害人自述摄药时间相一致。结论头发分段分析可提供摄药频度与摄药时间信息,在药物辅助犯罪案件中具有独特的证据价值。     

Radioimmunological determination of cocaine in human hair

A simple procedure for the determination of cocaine in human hair was described. After washing hair samples were crushed in 0.1 m HCl and incubated overnight at 45 degrees C. The acid extracts were neutralized with 1 m NaOH. Phosphate buffer (pH 7.4) was added to the extracts. The cocaine concentrations were measured by radioimmunoassay. Detection in hair was achieved in all hair samples obtained from cocaine users. This method appears to be suitable for the routine determination of cocaine.     

Metalloligand homeostasis: molecular basis of iatrogenic and technogenic trace element deficiency

It is well known that a toxic effect of some medicines is the result of their in vivo interactions with trace elements leading to disturbance of trace element balance in the living body. The Mossbauer spectrometry technique has been used for toxicochemical evaluation of iron-bearing medicines. This method can be used in forensic toxicology. We studied composition of trace elements in the hair of children living in Macedonia: in polluted territory (the town of Veles, the study group) versus in unpolluted one (Ivankovci village, the control group). AES-ICP and ICP-MS techniques were used. We discovered that the hair of children living in the polluted territory contain significantly elevated concentrations of Pb (in 43% cases), Hg, Ni (14%), Cd (21%), Cu (16%), Sn, As, Na, Se and subnormal concentrations of Mg (in 51% cases), Mn, Cr and Li.     

应用SEM/EDX和ICP-AES检测元素成份判定致伤工具

目的应用扫描电镜/能谱联合分析仪(Scanning electron microscopy & Energy dispersive X-ray apparatus SEM/EDX)和电感耦合原子发射等离子光谱(inductively coupled plasma-atom emission spectrometer ICP-AES)对金属致伤工具本身及所致创口残留物元素成分分析,探讨两者在推断认定此类工具的应用条件及价值.方法镀层和普通铁质工具在乳猪皮肤各致创5例,SEM/EDX对创口内遗留金属颗粒元素检测;用标准样品检测实验方法的精确度;普通铁质工具于刀背、刀刃处各取5个样本,ICP-AES测定元素成分与含量.结果镀锌工具所致创口中存在单一含有锌的金属颗粒,镀黄铜工具则同时含有锌和铜,未发现其它元素;不锈钢或普通铁质菜刀创口中,发现同时含有铁、铬、硅或铁、锰、硅的颗粒;除5号菜刀外同一把铁质菜刀在刀刃、刀背处元素含量无明显差别;ICP-AES分析表明不锈钢菜刀之间在铬、锰、硅、铜、钼和5号刀背部以及其他铁质菜刀在锰、硅元素含量差别具有显著意义,5号刀刃部锰、硅、钼、钛、磷、硫、镍元素RSD明显升高.结论SEM/EDX可以通过创口的检测对金属致伤工具进行种类的推断认定,ICP-AES则可在同种类致伤工具中进行相对同一的判定有应用价值.     

Preparation and application of a fortified hair reference material for the determination of methamphetamine and amphetamine

Quality assurance is one of the major issues in forensic analytical laboratories, where the need for a reference material (RM) has rapidly increased. RMs are very useful for method development and validation, internal quality control or proficiency tests. In the present study, we prepared a RM using drug-free hair for the determination of methamphetamine (MA) and its main metabolite, amphetamine (AP) according to the recommendations of ISO Guide 35. The concentrations of MA and AP were determined using two extraction methods, agitation with 1% HCl in methanol at 38 degrees C and ultrasonication with methanol/5M HCl (20:1), followed by gas chromatography/mass spectrometry (GC/MS) after derivatization with trifluoroacetic anhydride (TFAA). The assignment of values was conducted through the homogeneity study and characterization of the material. Furthermore, an internal proficiency test was performed with the prepared RM, of which the results were compared with those of the authentic hair RM prepared in our previous study. As a result, a hair RM containing MA and AP was prepared at the level of 4.86+/-0.69 ng/mg and 4.63+/-0.44 ng/mg, respectively. Most participants showed satisfactory performances in the internal proficiency test with the both RMs. The hair RM prepared in this study demonstrated its suitability for quality assurance in forensic laboratories.     

Magnesium, calcium and zinc fluctuations on skin induced injuries in correlation with time of induction

In the present study, fluctuations of trace elements Mg, Ca and Zn concentrations with time on skin-induced injuries was investigated. To accomplish this, 144 animals (pig) aged between 5-6 months scheduled for food provision process (slaughter) were used. At the gluteus area, injuries were induced prior to slaughter at intervals of 30 s, 30 min, 1, 2, 4, 8 h. Local anaesthesia and cold therapy for prompt relief of pain (ethylchloride, C2H5Cl) was applied. Postmortem tissue excision in and around the injured site was promptly performed. The tissue obtained was segmented into three zones of equal distances (2 cm) in between and weighed 3 g wet weight. Tissue specimens were analysed by atomic absorption spectroscopy for the three elements. The results were correlated with time of injury. Suggestive alterations in trace elements mean concentrations with time were confirmed. The ratios of the mean in twos (Ca/Zn, Ca/Mg, Mg/Zn) versus time were graphed. Effectively, the curves achieved by analysing postmortem tissues, serve to estimate the time of an injury induced in vivo.     

Detection of meperidine and its metabolites in the hair of meperidine addicts

The presence of meperidine and its metabolites in the hair of meperidine addicts was investigated using GC–MS (EI, PCI). Meperidine and its three metabolites – normeperidine, N-methoxy meperidine and acetyl normeperidine, were found in hair samples from addicted subjects. Methods for the simultaneous determination of meperidine and its metabolites by GC–MS-SIM were also established for human hair samples. After the addition of d₄-meperidine as an internal standard, hair samples weighing 5 mg were incubated in 0.1 M HCl at 45°C overnight, and the resulting digests were extracted with ether. The recoveries were greater than 80%, with coefficients of variation (CVs) between 4.48 and 8.31%. The calibration curves for meperidine and normeperidine in hair were linear over a concentration range of 1 to 500 ng per mg of hair, with correlation coefficients of r=0.9990 and r=0.9992, respectively. Values less than 0.25 ng/mg of hair were cut off. Hair samples obtained from 60 drug addicts were analyzed using this method, and the content of meperidine and normeperidine was determined to be 103±130 and 117±143 ng/mg, respectively. Sectional analysis revealed that meperidine was present and stable in hair for at least 20 months, but normeperidine content at the level of the hair root was higher compared to the tip of the hair shaft. The results also revealed that there was a correlation between the subject’s drug abuse history and the distribution of drug along the hair shaft, and between the doses of meperidine and drug content presented in hair.     

Measurement of Uncertainty for Aqueous Ethanol Wet‐Bath Simulator Solutions Used with Evidential Breath Testing Instruments

Aqueous ethanol wet‐bath simulator solutions are used to perform calibration adjustments, calibration checks, proficiency testing, and inspection of breath alcohol instruments. The Toxicology Bureau of the New Mexico Department of Health has conducted a study to estimate a measurement of uncertainty for the preparation and testing of these wet‐bath simulator solutions. The measurand is identified as the mass concentration of ethanol (g/100 mL) determined through dual capillary column headspace gas chromatography with flame ionization detector analysis. Three groups were used in the estimation of the aqueous ethanol wet‐bath simulator solutions uncertainty: GC calibration adjustment, GC analytical, and certified reference material. The standard uncertainties for these uncertainty sources were combined using the method of root‐sum‐squares to give u_c = 0.8598%. The combined standard uncertainty was expanded to U = 1.7% to reflect a confidence level of 95% using a coverage factor of 2. This estimation applies to all aqueous ethanol wet‐bath simulator solution concentrations produced by this laboratory.     

Determination of methadone in human hair by radioimmunoassay

The concentrations of methadone in human hair were measured. The washed hair was cut in 1-mm pieces approximately, then incubated overnight at 45 degrees C with 0.1 m HCl. The extracts were alcalized by 1 m NaOH and diluted by phosphate buffer, pH 7.4. The methadone concentrations were determined by radioimmunoassay. The method is simple, rapid, and practicable for routine determination.     

Segmental analysis for cocaine and metabolites by HPLC in hair of suspected drug overdose cases

Hair samples of eight postmortem cases were analyzed in segments of 1 to 3 cm for cocaine, benzoylecgonine and cocaethylene. Samples were prepared for analysis by digestion in 0.1 M HCl and subsequent extraction with mixed-mode solid-phase extraction columns. Measurement was made by reversed-phase, narrow-bore HPLC and fluorescence detection using two laboratory-made internal standards. The concentrations were in the region of 0.29-316 ng/mg of hair for cocaine, 0.43-141 ng/mg of hair for benzoylecgonine and 0.93-1.83 ng/mg of hair for cocaethylene. All eight investigated cases had cocaine-positive segments. In six of the cases, all segments were positive, suggesting regular cocaine use and two showed in-between negative segments indicating an interruption or a change of the abuse intensity. The results showed a second, remarkable observation, i.e. enormous concentration differences (factor >150) for both cocaine and benzoylecgonine between the different subjects. Furthermore, interindividual cocaine/benzoylecgonine ratios ranged from 0.02 to 8.43. We believe these observations could in part be attributed to both some of the still existing limitations in the analytical approach(es), especially the mandatory hair washing steps, and in our still too limited knowledge of the hair incorporation processes. Nevertheless, in some cases, segmental analysis proved to be an important tool to distinguish, together with postmortem examination, deadly chronic abuse from single acute drug overdosage.     

双眼交替微量取样检测兔玻璃体液钾镁离子浓度推测死亡时间

目的研究死后眼玻璃体液钾镁离子浓度变化及其与死亡时间的关系。方法取健康家兔处死,死后不同时间于双眼玻璃体液交替微量取样,采用全自动生化分析仪检测样本中[K+]、[Mg2+],对所得数据进行统计学处理。结果死后12~120h,家兔玻璃体液中[K+]由11.01mmol/L上升至32.97mmol/L,[Mg2+]1.12mmol/L上升至2.22mmol/L,两种离子浓度与PMI进行回归分析自变量为[K+]的二次多项式回归方程为y=0.1756x2-3.3188x+29.804(R2=0.9868);自变量为[Mg2+]的二次多项式回归方程为y=-46.916x2+248.01x-213.81(R2=0.9340);自变量为[K+]和[Mg2+]的二次多项式回归方程为y=-17.55-4.82[K+]+0.20[K+]2+75.77[Mg2+]-19.47[Mg2+](R2=0.9881)。用[K+]的方程推测PMI,当[K+]<26.0mmol/L(PMI<60h)时,平均偏离时间为2.7~9.4h,当[K+]>28mmol/L(PMI>72h)时,平均偏离时间>15h;用[Mg2+]的方程推测PMI,平均偏离时间几乎均在10h以上;用二元方程推测PMI,平均偏离时间较前两者小。结论死后眼玻璃体液[K+]、[Mg2+]随时间延长而升高,且浓度变化与时间呈强相关性。但从实际运用角度考虑,R2<0.98,或平均预测偏离时间过大的回归方程,不宜用于PMI推测;应用多指标建立多元回归方程是提高推测PMI准确性的可行方法。     

Amphetamine, cocaine and cannabinoids use among truck drivers on the roads in the State of Sao Paulo, Brazil

Lysergic acid diethylamide (LSD) is a potent hallucinogen, active at very low dosage and its determination in body fluids in a forensic context may present some difficulties, even more so in hair. A dedicated liquid chromatography-electrospray-tandem mass spectrometry (LC-ES-MS/MS) assay in hair was used to document the case of a 24-year-old man found dead after a party. Briefly, after a decontamination step, a 50mg sample of the victim's pubic hair was cut into small pieces (<1mm length), and incubated overnight in 3mL of phosphate buffer pH 5 at room temperature. After a liquid-liquid extraction (dichloromethane/ether), the extract was analyzed using a LC-ES-MS/MS method exhibiting a limit of quantification of 0.5pg/mg for LSD. A LSD concentration of 0.66pg/mg of pubic hair was observed. However, this result remains difficult to interpret owing to the concomitant LSD presence in the victim's post mortem blood and urine, the lack of previously reported LSD concentrations in hair, and the absence of data about LSD incorporation and stability in pubic hair.     

Segmental analysis for cocaine and metabolites by HPLC in hair of suspected drug overdose cases

Hair samples of eight postmortem cases were analyzed in segments of 1 to 3 cm for cocaine, benzoylecgonine and cocaethylene. Samples were prepared for analysis by digestion in 0.1 M HCl and subsequent extraction with mixed-mode solid-phase extraction columns. Measurement was made by reversed-phase, narrow-bore HPLC and fluorescence detection using two laboratory-made internal standards. The concentrations were in the region of 0.29–316 ng/mg of hair for cocaine, 0.43–141 ng/mg of hair for benzoylecgonine and 0.93–1.83 ng/mg of hair for cocaethylene. All eight investigated cases had cocaine-positive segments. In six of the cases, all segments were positive, suggesting regular cocaine use and two showed in-between negative segments indicating an interruption or a change of the abuse intensity. The results showed a second, remarkable observation, i.e. enormous concentration differences (factor >150) for both cocaine and benzoylecgonine between the different subjects. Furthermore, interindividual cocaine/benzoylecgonine ratios ranged from 0.02 to 8.43. We believe these observations could in part be attributed to both some of the still existing limitations in the analytical approach(es), especially the mandatory hair washing steps, and in our still too limited knowledge of the hair incorporation processes. Nevertheless, in some cases, segmental analysis proved to be an important tool to distinguish, together with postmortem examination, deadly chronic abuse from single acute drug overdosage.     

Methadone and EDDP in hair from human subjects following a maintenance program: results of a pilot study

A specific method has been developed for the quantitative determination of methadone (MTD) and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), in hair.An amount of 50mg hair samples were incubated in 0.01M HCl overnight at 60 degrees C and deuterated internal standards of MTD and EDDP were added before extraction. Hydrolyzed solutions were extracted by automated solid-phase extraction procedure and analyzed on a gas chromatography (GC) coupled to a ion trap mass spectrometer (MS). Positive chemical ionization was used with acetonitrile as liquid reagent. The different validation parameters, linearity, repeatability, recovery and detection limits are presented. A relative standard deviation (R.S.D.) of 12 and 11% was obtained for the repeatability of MTD and EDDP, respectively. The limits of quantification (LOQ) was 0.05ng/mg for MTD and 0.2ng/mg for EDDP.A number of 26 hair samples from human subjects following a long-term MTD therapy were analyzed by this method. Blood samples of these subjects were analyzed with a routine method using a liquid-liquid extraction and GC/nitrogen phosphorus detector (NPD). MTD was quantified in blood and hair samples and EDDP found in 50% of the hair sample.A comparison was made between the concentrations found in blood or in hair and the dose administrated. This study could demonstrate that there is no relation between the administrated dose and MTD or EDDP concentrations in hair.