Heroin impurity profiling: trends throughout a decade of experimenting.

Heroin is still one of the most frequently abused drugs of today. All over the world, law enforcement agencies try to eradicate the illicit production and trafficking of this potent and highly addictive narcotic. To this aim, important information is provided by physical and chemical toxicological analysis of confiscated samples, with special attention for the identification and the quantification of minor components, such as the impurities related to the origin and manufacturing. By combining these data complex characterisations, i.e. impurity profiles, chemical signatures or fingerprints, can be obtained and used for comparative analysis. This review focuses on heroin impurity profiling during the 1990s, proclaimed by the United Nations as the 'Decade for Eradicating Drug Abuse'. Special attention will be given to the new trends in analytical techniques as well as in data handling strategies, so called chemometrics, to produce these profiles. The latter can be used in comparative analysis of seized heroin samples for tactical (batch-to-batch comparison) and strategic (origin determination) intelligence purposes.     

Effect of Extraction Procedure and Gas Chromatography Temperature Program on Discrimination of MDMA Exhibits

Analysis of impurities in seized MDMA tablets can be used to determine the synthesis method used and to identify links among exhibits. However, no standardized method exists to generate impurity profiles, limiting comparisons among different laboratories. This research investigated the effect of extraction procedure and gas chromatography temperature program on the resulting impurity profiles. Five exhibits were extracted using liquid–liquid extraction (LLE) and headspace solid‐phase microextraction (HS‐SPME), then analyzed using two different temperature programs. Profiles were statistically assessed using principal components analysis. While LLE was more reproducible, more compounds were extracted using HS‐SPME, thus providing more informative chemical profiles. The longer temperature program (53 min vs. 36 min) allowed greater discrimination of exhibits, due to improved precision as a result of an extended hold time (12 min). This research further highlights the need for standardized extraction and analysis procedures to allow comparison of chemical profiles generated in different laboratories.     

Investigation of trace inorganic elements in street doses of heroin

Sixteen trace elements found in 309 street heroin samples, piped water and contaminated water were determined using inductively coupled plasma-mass spectrometry. All the street heroin samples were found to contain high levels of sodium, a reflection of the use of sodium bicarbonate during heroin synthesis. Additionally, this element was also found to be one of the potential contaminants acquired from the piped water. Calcium could be derived from lime while iron, aluminum and zinc could have come from the metallic container used in the processing/cutting stage. The levels of these elements remained low in the heroin and it could be due to the dilution effects from the addition of adulterants. Statistical validation was performed with six links of related heroin samples using principal component analysis to find the best pretreatment for sample classification. It was obtained that normalization followed by fourth root showed promising results with 8% errors in the sample clustering. The technique was then applied to the case samples. Finally, the result suggested that the case samples could have originated from at least two major groups respectively showing unique elemental profiles at the street level.     

Impurities, adulterants and diluents of illicit heroin in Denmark (Jutland and Funen)

The contents of impurities, adulterants and diluents in 77 samples of illicit heroin were determined by a combination of high-performance liquid chromatography and gas chromatography. The origin of each sample was characterized by calculating the content of the opium alkaloids in relation to the heroin content. The routes of distribution were compared by determination of the contents of caffeine, procaine and sugars. The results were used as a "chemical fingerprint" of each sample. The results indicate that it is difficult to prove, with certainty, that two samples are identical. However, in most cases, by determining the amounts of impurities, adulterants and diluents in heroin samples, it will be possible to ascertain whether two samples are different and, in many cases, to determine with reasonable certainty whether two samples are identical.     

Particle size analysis of six illicit heroin preparations seized in the U.K.

Illicit heroin is rarely pure and may contain a number of other substances. The total particle size distribution in six illicit heroin preparations was analysed using a Malvern 2600 Particle Analyser and by sieving. The pattern of heroin distribution amongst these particles was determined by HPLC. The results show that a representative illicit heroin particle is approximately 45 μm in diameter (137 pmol heroin) and that particles occur over a wide size range, from at least 5.8 to 564 μm in diameter. Aggregated data for the samples studied showed that the overall distribution of heroin particle size largely follows the total particle size distribution, but that this correlation is not necessarily true for individual drug preparations. These results have important implications for any system designed to detect concealed illicit heroin preparations by collection and analysis of drug particles.     

Identification of heroin in street doses using 1D-TOCSY nuclear magnetic resonance

Heroin street doses are complex mixtures commonly analyzed in forensic laboratories. Identification of the illicit substance in these street doses is among the primary analytical tasks of a forensic laboratory. We demonstrate that the one-dimensional ID-TOCSY NMR experiment permits identification of heroin in standard mixtures containing up to ten or more different components. This method produces an easily-identified and effective "fingerprint" for heroin within a mixture of other substances. The method has been successfully tested as a tool for identification of heroin in street doses from police casework in Israel. This NMR technique is robust and quick (a measurement can be carried out in 10-15 min), and it does not require any preliminary physical or chemical treatments of the sample to be examined, due to the effective spectroscopic "filtering" of the interfering components. The ID-TOCSY NMR method can potentially be used in combination with additional analytical methods as a routine tool in forensic laboratories to positively identify heroin for court purposes.     

Heroin impurity profiling. A harmonization study for retrospective comparisons

Three laboratories present a harmonised system for the retrospective comparison of south west Asian heroin. It consists of an improved gas chromatographic (GC) profiling method and a computerised data retrieval. The investigations of the GC were necessary with a view to improve the reproducibility of the system. The necessity of a strict quality control is emphasized. The peaks of the GC profile were investigated for abundance, intensity, GC behaviour (reproducibility) and correlations; 16 of them were selected for describing the heroin profile in the database. The results from intra-lab profile comparisons are reported. The reproducibility of the analysis was good and the variation between the samples was large, thus, allowing conclusions with a high degree of certainty. The criteria of similarity were defined. The system is successfully running in all three labs.In connection with inter-laboratory comparison, the aspects of method harmonisation and standardisation are discussed. It appeared that the GC method is a very subtile one, urging for a strict standardisation between the three labs. Despite a long cooperation between three well-equipped and experienced labs, a more or less serious loss of reproducibility was noticed in the inter-lab results in comparison with the intra-lab results. The loss could for the greater part be attributed to the (limits of the) GC technique; a number of compounds, necessary for making the discrimination between samples, showed difficult chromatographic behaviour, leading to insufficient inter-lab reproducibility. Using the actual variables, improvements in performance can hardly be expected in the near future. The loss of reproducibilty implies that the number of false positive matches in a database search increases. This may strongly reduce the value of a relatively large, international database. The study shows that so far, the best option for international comparison is the analysis in a central laboratory. The idea of local determination at a large number of national labs and the use of a common database is not a realistic aim for this type of analysis.     

The detection and estimation of (A) arsenic in opium, and (B) strychnine in opium and heroin, as a means of identification of their respective sources

Samples of opium with arsenic as an adulterant, and both opium and heroin with strychnine as an adulterant are not infrequently encountered in the local drug scene. The paper describes a method for the possible identification of the sources of opium and heroin in the local market on the basis of an accurate quantitation of the adulterant arsenic and strychnine contents of the respective samples. A possible extension of this concept, would be the possibility of a similar identification of sources outside the country with a view to establishing channels of entry from abroad. Arsenic is determined by the Gutzeit method while strychnine is estimated by high performance liquid chromatography (HPLC).     

Changes in place of origin of heroin seized in Denmark from 1981 to 1986. "Chemical fingerprint" of 138 samples

Hundred thirty-eight samples of heroin weighing more than 0.1 g seized between 1981 and 1986 were characterized according to their contents of opium alkaloids, adulterants, and diluents together with their form and color. The "chemical fingerprint" was used to establish a change in the heroin during the period. As compared to the first few years covered by the survey, a predominant number of the samples at the end of the period were in the base form and contained the opium alkaloids papaverine and noscapine. In particular, the concentration of noscapine as related to the heroin content of each sample had increased considerably, indicating Pakistan or Iran as being the places of origin of most of the heroin seized in Denmark at the end of the period.     

A simplified clustering method for novice narcotic chemists

Statistical classification remains the most useful statistical tool for forensic chemists to assess the relationships between samples. Many clustering techniques such as principal component analysis and hierarchical cluster analysis have been employed to analyze chemical data for pattern recognition. Due to the feeble foundation of this statistics knowledge among novice drug chemists, a tetrahedron method was designed to simulate how advanced chemometrics operates. In this paper, the development of the graphical tetrahedron and computational matrices derived from the possible tetrahedrons are discussed. The tetrahedron method was applied to four selected parameters obtained from nine illicit heroin samples. Pattern analysis and mathematical computation of the differences in areas for assessing the dissimilarity between the nine tetrahedrons were found to be user-convenient and straightforward for novice cluster analysts.     

DNA profiling from heroin street dose packages

A large amount of heroin street doses are seized and examined for drug content by the Israel police. These are generally wrapped in heat-sealed plastic. Occasionally it is possible to visualize latent fingerprints on the plastic wrap itself, but the small size of the plastic item and the sealing process makes the success rate very low. In this study, the possibility of extracting and profiling DNA from the burnt edge of the plastic wrap was investigated. The idea was based on the assumption that epithelial cells might be trapped during the sealing process. The results show that there are sufficient quantities of DNA deposited at the "amorphic" burnt edges of sealed street doses for DNA profiling to be carried out. A controlled experiment using a known donor was performed. This subject carried out sealing of "street drug" packages and consequent DNA extractions were performed to show that known DNA profiles could be recovered from such packages, as a result of handling by the "packer." "Square-like" burnt edges did not yield DNA profiles, probably because of differences in the sealing process. It was also shown that DNA could be recovered from the plastic wrap itself and not only from the amorphic burnt edges. As heroin dealers and drug users are often involved in other crimes and run-ins with the law, the effective extraction and addition of their DNA profiles from such items of evidence to the newly established DNA database in Israel provides new avenues in the continued fight against crime and drug traffickers.     

Isolation and purification of heroin from heroin street samples by preparative high performance liquid chromatography

The present study established a novel method using preparative high performance liquid chromatography to isolate and purify heroin·HCl from heroin street samples to be used as a reference standard. Different kinds of mobile phases and columns were used, ultimately the mobile phase consisting of hexane-isopropanol-methanol (65:28:7, v/v) and the SIL preparative column prepared in laboratory were selected as the final condition. Heroin was further purified by the drowning-out crystallization method using isopropanol-methanol (50:1, v/v) and hexane as drowning-out anti-solvents and salting-out agents, respectively. The purity was assessed by analytical high performance liquid chromatography and the confirmation of the chemical structure was performed by IR and NMR. About 110.7mg of heroin·HCl at a purity of over 99.52% was obtained from 180mg of heroin street samples which contained 156.15mg of heroin·HCl component by preparative high performance liquid chromatography. This method is suitable for preparing heroin standards in forensic science area.     

A Bayesian approach based on Kalman filter frameworks for bullet identification

When a bullet is fired from a barrel, random imperfections in the interior surface of the barrel imprint 3-D micro structures on the bullet surface that are seen as striations. Despite being random and non-stationary in nature, these striations are known to be consistently reproduced in a unique pattern on every bullet. This is a key idea in bullet identification. Common procedures in the field of automatic bullet identification include extraction of a feature profile from bullet image, profile smoothing and comparison of profiles using normalized cross correlation. Since the cross correlation based comparison is susceptible to high-frequency noise and nonlinear baseline drift, profile smoothing is a critical step in bullet identification. In previous work, we considered bullet images as nonlinear non-stationary processes and applied ensemble empirical mode decomposition (EEMD) as a preprocessing algorithm for smoothing and feature extraction. Using EEMD, each bullet average profile was decomposed into several scales known as intrinsic mode functions (IMFs). By choosing an appropriate range of scales, the resultant smoothed profile contained less high-frequency noise and no nonlinear baseline drift. But the procedure of choosing the proper number of IMFs to reduce the high-frequency noise effect was manual. This poses a problem in comparison of bullets whose images contained less or more noise in comparison to others because their useful information may be present in the corresponding discarded IMFs. Moreover, another problem arises when the bullet type changes. In this case manual inspection is needed once more to figure out which range of IMFs contain less high-frequency noise for this particular type of bullet. In this paper, we propose a novel combination of EEMD and Bayesian Kalman filter to solve these problems. First the bullet images are rotated using Radon transform. The rotated images are averaged column-wise to acquire averaged 1-D profiles. The nonlinear baseline drifts of averaged profiles are removed using EEMD algorithm. The profiles are then processed by a Kalman filter that is designed to automatically and optimally reduce the effect of high-frequency noise. Using Expectation Maximization (EM) technique, for each averaged profile, the parameters of Kalman filter are reconfigured to optimally suppress the high-frequency noise in each averaged profile. This work is the first effort that practically implements the Kalman filter for optimal denoising of firearm image profiles. In addition, we believe that Euclidean distance metric can help the normalized cross-correlation based comparison. Therefore, in this paper, we propose a comparison metric that is invariant to start and endpoints of firearm image profiles. This metric combines the prized properties of both Euclidean and normalized cross-correlation metrics in order to improve identification results. The proposed algorithm was evaluated on a database containing 180 2-D gray-scale images acquired from bullets fired from different AK-47 assault rifles. Although the proposed method needs more calculations in comparison to conventional methods, the experiments showed that it attained better results compared with the conventional methods and the previous method based on EMD in the field of automatic bullet identification.     

Comparative gas chromatographic studies of heroin samples. Results of a pilot project in West Germany in 1982

From 1.4. -30.10.1982 all heroin samples weighing more than 5 g seized in the States of Baden-Württemberg, Hesse and by the Bundeskriminalamt were analyzed by capillary gas chromatography during a pilot project. For comparison of samples ratios of concentrations of heroin (including its decomposition products 0(6)-acetylmorphine and morphine) and its natural by-products of synthesis acetylcodeine, papaverine, and narcotine (noscapine) were determined. The application of these parameters and further qualitative and quantitative criteria for heroin comparison for investigative and legal purposes are discussed.     

Stable isotope analyses of heroin seized from the merchant vessel Pong Su

A new type of heroin HCl seized in Australia was examined by stable isotope analysis. The final origin/process classification of these samples by chromatographic signature profiles of the impurity/manufacturing by-products was previously determined to be "unknown" by two independent national laboratories. Various drug enforcement authorities speculated that the heroin might be from a new region or new illicit process due to the unusual chromatographic impurity profiles that were present. Samples from 20 different kilogram packages were examined for isotopic content to determine if the samples fit isotopic patterns of known origins or if they were unique to any known origins. Authentic specimens from Southeast Asian (N=59), Southwest Asia (N=37), South America (N=104), and Mexico (N=21) we concomitantly examined for comparison purposes. Both continuous flow elemental analysis-isotope ratio mass spectrometry and gas chromatography-isotope ratio mass spectrometry techniques were utilized. Heroin samples were also converted to morphine, without apparent isotopic fractionation, utilizing methanolic HCl for gas chromatography-isotope ratio mass spectrometry. The Pong Su samples were found to be isotopically and isotopically/alkaloidally distinct from the known origin/process classifications of Southwest Asian, Southeast Asian, South American, and Mexican.     

Heroin Overdose Deaths and Heroin Purity Between 1990 and 2000 in Istanbul,Turkey*

Abstract: Turkey has continuously experienced problems with abuse of, and addiction to, opium derivatives. In this study, we analyzed the relationship between heroin overdose deaths and the characteristics of seized opium derivatives. Data were gathered from the Council of Forensic Medicine of the Ministry of Justice in Istanbul from 1990 to 2000. There were 636 heroin‐related deaths during this period, 595 of which were classified as heroin overdose deaths. Mean crude and weighted heroin purities remained relatively constant and were calculated to be 46% (57–34%) and 51% (39–59%), respectively. The weight of heroin and the number of heroin seizures, but not the heroin purity, were significantly associated with the number of heroin‐related deaths. Prevention strategies are needed to reduce the number of deaths caused by overdoses in countries situated on drug trafficking routes. These strategies should focus on drug trafficking, by providing increased levels of, and support for, law enforcement, stopping the supply of precursor chemicals, and combating corruption among border officials.     

The illicit preparation of morphine and heroin from pharmaceutical products containing codeine: 'homebake' laboratories in New Zealand

Since 1983 a large number of small-scale illicit laboratories producing morphine and heroin from commercially available, codeine-based pharmaceutical products have been encountered in New Zealand. The codeine demethylation procedure is based on the use of pyridine hydrochloride. Very simple laboratory equipment and reagents are required and these can be utilised by people with little or no chemical background, following a recipe-like procedure. The process yields a characteristic product known as 'homebake'. This process is fully described.     

Heroin abuse and a gas chromatographic method for determining illicit heroin samples in Singapore.

The abuse of heroin (diacetylmorphine) in Singapore escalated sharply in 1975 and 1976, as indicated by the 35-fold increase in the number of heroin seizures and the 20-fold increase in the urine samples containing morphine since 1974. A rapid and simple GC method has been described to estimate diacetylmorphine (and caffeine). Monoacetylmorphine and acetylcodeine may be ascertained by an additional step involving acetylation. All gas chromatograms of a large number of samples analyzed consistently had the same pattern, indicating that they possibly had a common origin. This GC "fingerprint," together with the quantitative data, appears to be characteristic of the illicit Asian or Chinese type of heroin found in Singapore. The proportions of the four major ingredients in some twelve typical samples have been tabulated. Statistical data confirming the accuracy and reproducibility of the analytical method have also been presented.     

GC/MS determination of pyrolysis products from diacetylmorphine and adulterants of street heroin samples

The inhalation of heroin vapors after heating on aluminium foil ("chasing the dragon") is gaining popularity nowadays among heroin users seeking to avoid the risks of parenteral drug administration. The heroin-smoking procedure was simulated under laboratory conditions by heating the samples on aluminium foil at 250 to 400 degrees C and collecting the vapors in a condenser trap. A total of 72 pyrolysis products of diacetylmorphine, street heroin, residues from aluminium foils used to smoke street heroin, typical by-products, and adulterants were detected by gas chromatography/mass spectrometry (GC/MS). About half of these compounds could be identified. Diacetylmorphine (base and salt) undergoes substantial to complete degradation. Some typical street heroin constituents, like morphine, codeine, acetylcodeine, papaverine, and caffeine, are rather heat-stable. Other compounds, like noscapine and paracetamol, are pyrolyzed to a greater extent. The principal chemical reactions leading to the formation of pyrolysis products are desacetylation, transacetylation, N-demethylation, O-methylation, ring cleavage and oxydation.