A quick and automated method for profiling heroin samples for tactical intelligence purposes

A computerized procedure is presented for the profiling and comparison of illicit heroin seizures. The system involves the derivation and gas chromatographic separation of five major constituents followed by a fully automatic data analysis and transfer to a PHP/MySQL database. Comparisons via the square cosine function between a single chromatographic profile and the whole database (several hundred of samples) are performed in a few seconds. Advantages of this profiling method compared to the classical minor constituents one are discussed.     

Cocaine profiling. A method of comparative substance studies of illegal cocaine samples]

Illegal cocaine were extracted in acidic medium. The extracts contain significant amounts of truxinic and truxillic acids. Successful comparism of cocaine out of different sources can be achieved by chromatographing trimethylsilyl- or dimethyl-t.-butylsilyderivates. The application of the method Ist limited by the purity of the samples.     

Cocaine profiling for strategic intelligence purposes, a cross-border project between France and Switzerland. Part I. Optimisation and harmonisation of the profiling method

Optimisation and harmonisation of analytical and statistical methodology have been carried out between two forensic laboratories (Lausanne, CH and Lyon, F) in order to provide drug intelligence for cross-border cocaine seizures. The aim was to improve the gas chromatographic analysis of cocaine samples for profiling. Some important validation parameters were tested to verify the developed method and demonstrate its profiling capacity: the selectivity of the method with retention time reproducibility, the choice of a derivatisation agent improving the chromatography (MSTFA, BSA, TMSI and BSTFA+TMCS 1%), the cutting agents influence (matrix effect), the influence of the sample storage conditions and the sample quantity to weigh for analyses. Eight main alkaloids, which represent the sample signature, have been selected: ecgonine methyl ester, ecgonine, tropacocaine, benzoylecgonine, norcocaine, cis- and trans-cinnamoylcocaine and 3,4,5-trimethoxycocaine. Their stability in the solvent used (CHCl(3)/pyridine) was demonstrated. In order to reach the final objective, which is the comparison of samples seized and analyzed in two different laboratories, the harmonisation of the profiling method between the two laboratories had to be ensured and is the subject of ongoing research.     

Cocaine profiling for strategic intelligence, a cross-border project between France and Switzerland: part II. Validation of the statistical methodology for the profiling of cocaine

Harmonisation and optimization of analytical and statistical methodologies were carried out between two forensic laboratories (Lausanne, Switzerland and Lyon, France) in order to provide drug intelligence for cross-border cocaine seizures. Part I dealt with the optimization of the analytical method and its robustness. This second part investigates statistical methodologies that will provide reliable comparison of cocaine seizures analysed on two different gas chromatographs interfaced with a flame ionisation detectors (GC-FIDs) in two distinct laboratories. Sixty-six statistical combinations (ten data pre-treatments followed by six different distance measurements and correlation coefficients) were applied. One pre-treatment (N+S: area of each peak is divided by its standard deviation calculated from the whole data set) followed by the Cosine or Pearson correlation coefficients were found to be the best statistical compromise for optimal discrimination of linked and non-linked samples. The centralisation of the analyses in one single laboratory is not a required condition anymore to compare samples seized in different countries. This allows collaboration, but also, jurisdictional control over data.     

Comparison analysis of illicit cocaine samples.

A rapid method for comparison analysis of illicit cocaine samples has been developed. The raw data are obtained by capillary gas chromatography using a nitrogen-phosphorus detector. The area ratios of four alkaloids (tropacocaine, norcocaine, cis-cinnamoylcocaine, and trans-cinnamoylcocaine) to cocaine are calculated for each sample. These ratios are compiled in a computer database which allows easy comparison of samples and makes possible reliable conclusions regarding their commonality of origin.     

海洛因技术分析在禁毒情报方面的应用

本文通过统计缴获样本的化学检测信息及案卷资料,得到有关毒品的来源、含量、地区分布及掺假情况等情报信息。这些情报信息可以作为我国禁毒部门从战术角度(样本间的比较)和战略角度(毒品来源确定)研判我国毒品形势的手段之一。     

The routine profiling of forensic heroin samples

A method for the routine profiling of illicit heroin samples received in casework has been developed which depends on simple and straightforward sample pretreatment, followed by gas chromatography on a capillary column using flame-ionization detection. The factors affecting the choice of each aspect of the procedure are discussed, as are the statistical data for sampling and the chromatography. Components of illicit heroin derived from opium and other adulterants have been identified. The significance of data from samples examined in 1986 is discussed.     

One-step liquid-liquid extraction of cocaine from urine samples for gas chromatographic analysis

An improved technique for cocaine extraction from urine samples for gas chromatographic (GC) analysis is described. Employing a simple liquid-liquid extraction (LLE) of cocaine with a mixture of ethyl ether:isopropanol (9:1) the method presents a mean recovery of 74.49%. Limit of detection (LOD) and limit of quantification (LOQ) were 5 and 20 ng/ml, respectively. The method is highly precise (coefficient of variation (CV) <8%) and linear from 20 to 2000 ng/ml. It can he applied to detect the presence of cocaine in urine as a marker of its recent use in drug abuse treatment protocols.     

Elemental analysis of soil samples for forensic purposes by inductively coupled plasma spectrometry--precision considerations

Major and trace elemental composition provides a powerful basis for forensic comparison of soils, sediments and rocks. However, it is important that the potential 'errors' associated with the procedures are fully understood and quantified, and that standard protocols are applied for sample preparation and analysis. This paper describes such a standard procedure and reports results both for instrumental measurement precision (repeatability) and overall 'method' precision (reproducibility). Results obtained both for certified reference materials and example soils show that the instrumental measurement precision (defined by the coefficient of variation, CV) for most elements is better than 2-3%. When different solutions were prepared from the same sample powder, and from different sub-sample powders prepared from the same parent sample, the CV increased to c. 5-6% for many elements. The largest variation was found in results for certified reference materials generated from 23 instrument runs over an 18 month period (mean CV=c. 11%). Some elements were more variable than others. W was found to be the most variable and the elements V, Cr, Co, Cu, Ni and Pb also showed higher than average variability. SiO2, CaO, Al2O3 and Fe2O3, Rb, Sr, La, Ce, Nd and Sm generally showed lower than average variability, and therefore provided the most reliable basis for inter-sample comparison. It is recommended that, whenever possible, samples relating to the same investigation should be analysed in the same sample run, or at least sequential runs.     

A rapid gas chromatographic method for the fingerprinting of illicit cocaine samples.

A gas chromatographic (GC) fingerprint method, based on the presence or absence of six congeners, was developed for illicit cocaine samples. The fingerprint utilizes the relative abundances of these congeners towards each other, disregarding cocaine as the main constituent, and can be expressed numerically or graphically in the form of pictograms for rapid visual comparison. The method can be applied directly to a solution of the sample in chloroform, without previous workup procedures. More than 70 unrelated samples were analyzed and a great variation was observed in the parameter composition. On the other hand, a remarkable similarity could be seen between related samples. The GC fingerprint method may be considered an important contribution for sample comparison, as is exemplified by a subdivision of the analyzed samples in different categories, based on the number and types of congeners found.     

2人份混合检材STR图谱分析

目的探讨混合检材STR图谱分析结果。方法收集了3例实际案例检材,提取DNA,PCR扩增后用310型遗传分析仪检测。结果当DNA含量差距不大时,2人份混合检材检验结果易于分析,当DNA含量差距较大时或者2人份以上混合检材,图谱分析非常困难。结论根据本文提出的问题和实验结果,当遇到这样的混合样品,分析结论一定要谨慎。     

Implementation of a semi-automated processing system for DNA profiling of forensic casework samples

The concept for a semi-automated processing system for DNA analysis of crime scene samples was developed at the Landeskriminalamt Baden-Württemberg (LKA BW) and comprises the extraction of genomic DNA from human cells by ChargeSwitch^® magnetic bead technology (CST), quantification of purified DNA by real-time PCR, amplification of short tandem repeats (STRs) by PCR and DNA fragment length analysis of STRs by capillary electrophoresis. Three liquid handling workstations from Tecan, a real-time PCR device and a 16-channel capillary electrophoresis (CE) system, both from Applied Biosystems (AB), are linked via laboratory data network. Transmission and management of sample and analysis data is enabled by a Laboratory Information and Management System (LIMS). Suitability for a wide range of stain types, early exclusion of DNA-free samples, barcode sample identification and prevention of cross-contaminations guarantee efficiency and high quality standards.     

Drug intelligence based on organic impurities in illicit MA samples

One major objective of the European project "Collaborative Harmonisation of Methods for Profiling of Amphetamine Type Stimulants" (CHAMP), funded by the sixth framework programme of the European Commission, consisted of the harmonisation of a gas chromatography/mass spectrometry (GC/MS) method for the analysis of organic impurities found in illicit methamphetamine (MA) samples in a drug intelligence perspective. Statistical analysis provided a selection of pertinent variables among the 43 organic impurities identified in the chromatograms. As for the 3,4-MethyleneDioxyMethAmphetamine (MDMA) study, correlation coefficients were used as a discrimination tool between populations of linked samples (from the same seizure) and unlinked samples (from different seizures). It was also shown that correlation measurements based on Pearson and cosine functions applied to the data pre-treated by normalisation to the sum of peak responses followed by the square root provided excellent discrimination between the two populations. The organic impurities profiling method was proved to be relevant for the characterization of samples from different seizures and their synthesis route patterns.     

Optimized conditions for simultaneous determination of opiates, cocaine and benzoylecgonine in hair samples by GC--MS

The present paper describes a qualitative and quantitative method for the simultaneous detection of opiates, cocaine and benzoylecgonine from human hair samples. Every step of the analytical procedure was studied to find the optimized conditions. Nine different incubation systems were examined. The influence of different pH values of samples on the isolation of analytes from the incubation media by Bond Elut cartridges and the stability of the compounds of interest in the different incubation media and conditions were investigated. The extracting power of different incubation media was studied as well. The phosphate buffer 0.1 N at pH 5 was chosen as the extraction medium in an optimized procedure for simultaneous determination of opiates, cocaine and benzoylecgonine in hair samples. The method developed was validated. Recoveries were 90% for morphine (M), 81% for 6-monoacetylmorphine (6-AM), 90% for codeine (CD), 86% for cocaine (C) and 90% for benzoylecgonine (BE). Relative standard deviation for inter-day precision was better than 12%. The limits of detection resulted as 0.05 ng/mg for M and C, as 0.08 for 6-AM and as 0.2 ng/mg for BE. Forty hair samples collected from drug abusers admitted to centers for detoxification treatment were analyzed obtaining 23 positive results for opiates and/or cocaine. Twelve hair specimens longer than 10 cm were analyzed following a sectional approach. In the six positive cases, it was interesting to find that the 6-AM/M ratio generally decreased for each sample from the proximal segment to the distal segments. Moreover, the 6-AM/M ratio was generally lower than 1 in the intermediate and distal segments.     

Elemental analysis of soil samples for forensic purposes by inductively coupled plasma spectrometry — precision considerations

Major and trace elemental composition provides a powerful basis for forensic comparison of soils, sediments and rocks. However, it is important that the potential ‘errors’ associated with the procedures are fully understood and quantified, and that standard protocols are applied for sample preparation and analysis. This paper describes such a standard procedure and reports results both for instrumental measurement precision (repeatability) and overall ‘method’ precision (reproducibility). Results obtained both for certified reference materials and example soils show that the instrumental measurement precision (defined by the coefficient of variation, CV) for most elements is better than 2–3%. When different solutions were prepared from the same sample powder, and from different sub-sample powders prepared from the same parent sample, the CV increased to c. 5–6% for many elements. The largest variation was found in results for certified reference materials generated from 23 instrument runs over an 18 month period (mean CV = c. 11%). Some elements were more variable than others. W was found to be the most variable and the elements V, Cr, Co, Cu, Ni and Pb also showed higher than average variability. SiO₂, CaO, Al₂O₃ and Fe₂O₃, Rb, Sr, La, Ce, Nd and Sm generally showed lower than average variability, and therefore provided the most reliable basis for inter-sample comparison. It is recommended that, whenever possible, samples relating to the same investigation should be analysed in the same sample run, or at least sequential runs.     

Spatial and temporal influences on bacterial profiling of forensic soil samples

Bacterial content may be helpful in differentiating forensic soil samples; however, the effectiveness of bacterial profiling depends on several factors, including uniqueness among different habitat types, the level of heterogeneity within a habitat, and changes in bacterial communities over time. To examine these, soils from five diverse habitats were tested over a 1 year period using terminal restriction fragment length polymorphism (TRFLP) analysis. Soil samples were collected at central locations monthly, and 10 feet in cardinal directions quarterly. Similarity indices were found to be least related among habitats, while the greatest bacterial similarities existed among collection locations within a habitat. Temporally, however, bacterial content varied considerably, and there was substantial overlap in similarity indices among habitats during different parts of the year. Taken together, the results indicate that while bacterial DNA profiling may be useful for forensic soil analysis, certain variables, particularly time, must be considered.     

Drug intelligence based on MDMA tablets data: 2. Physical characteristics profiling

One of the tasks of the European project entitled “Collaborative Harmonisation of Methods for Profiling of Amphetamine Type Stimulants” (CHAMP) funded by the sixth framework programme of the European Commission was to develop a harmonised methodology for MDMA profiling and the creation of a common database in a drug intelligence perspective. Part I was dedicated to the analysis of organic impurities formed during synthesis in order to investigate traffic tendencies and highlight potential links between samples, whereas this part focuses on physical characteristics of the MDMA tablets. Diameter, thickness, weight and score were demonstrated to be reliable and relevant features in this drug intelligence perspective. Distributions of samples coming from the same post-tabletting batch (post-TB) and samples coming from different post-TB were very well discriminated by using the squared Euclidean or the Manhattan distance on standardised data. Our findings demonstrated the possibility to discriminate between MDMA samples issued from different post-TB and to find out links between samples coming from a same post-TB. Furthermore, the hypothesis that most of the MDMA samples found on the international market come from the same countries was supported.     

Discrimination between sediment and soil samples for forensic purposes using elemental data: an investigation of particle size effects

This paper reports the results of an investigation to quantify variations in elemental concentrations amongst different particle size fractions obtained from a suite of sediment samples collected from the River Avon, UK. Concentrations of 49 elements determined by inductively coupled plasma spectrometry (ICP-AES and ICP-MS) were compared using conventional and multivariate statistical methods in order to assess compositional differences between different size fractions and between different samples. The results showed significant differences between different size fractions and the bulk sediments, but indicated that all of the size fractions considered (<150, 63-150, 20-63 and <20microm) provided an adequate basis on which to identify associations and differences between samples. It was concluded that, while in certain specific circumstances it may be most appropriate to make forensic comparisons based on a very narrowly defined particle size range, for the majority of purposes the <150microm fraction provides the best compromise between sample size requirements and data resolution.