A Chemical Profiling Of Seized Heroin Health Essay
Heroin is described as a narcotic which when taken can lead to various effects, these range from euphoria to lethargy and many states in between. In the UK is classified as a Class A drug, so its possession and use are illegal and warrant a fine or a custodial sentence.
The appearance of Heroin is from a white crystalline powder to a dark brown power depending on its purity. The % purity varies from sample to sample and from region to region. Heroin samples consist of both major and minor components present in the following levels
Major component - present in quantities > 1% relative to heroin
Minor component – present in quantity < 1% relative to heroin
The quantity of Heroin seized in England and Wales for the period 1997-2008 is presented in Appendix I. It is difficult to say with confidence what % these seizures represent of the total levels of heroin imported each year. One estimate (1) is that is represents approximately 5% of the entire heroin imported. Based on this approx 32 tonnes of Heroin are were imported into the England and Wales last year..
Another study (2) from Scotland estimates that seizures only represent 1% of the total amount of heroin consumed. Globally there are 4 major regions that produce Heroin
South West Asia – Afghanistan main supplier to UK (90%)
South East Asia – Burma China, Laos
The heroin produced from each of these locations is chemically different due to variations in , growing conditions, soil types, manufacturing procedures and additives.
Heroin profiling –policing perspective
A substantial amount of policing time and financial resources are spent on drug related crime. This includes direct involvement with drugs, arrests for supply, investigation smuggling operations and drug surveillance operations. There is also a lot of time spent on crimes committed which are as a result of drugs, these include
Theft, armed robbery, counterfeiting etc …..
Is it useful for policing service to become involved in heroin profiling. The simple answer is yes. There are numerous of reasons. A report from the United Nations Office on Drugs and Crime (UNODC) (3) outlines the importance of profiling to policing.
The use of drug profiling to policing is defined as Tactical information; information that can be used for evidential and judicial. It may be possible to establish if any links exist between seized samples from different locations. This may indicate a common source of the samples, which may lead to a particular smuggling gang. It may also connect individuals apprehended for the passion of heroin to particular batches. The profiling may also identify dealer and used networks (4).
The profiling of heroin seizures also provides strategic intelligence to the police. This operates at a high level that the tactical level. Strategic level intelligence involves using the information to identify the geographical origin of the sample. It may also identify the method used in the manufacture of the heroin, which could lead to a specific laboratory. Drug profiling alone will not answer all the tactical and strategic questions but it is an important factor along with other police intelligence in countering drug importation and use.
Heroin profiling –Health implications
There are a substantial number of deaths from related heroin each year in the UK. The number of deaths from Opiates (heroin, morphine & methadone) was 4,976 between 2000-2004 (5).
Can drug profiling save any lives?. Its difficult to answer this with any certainty. The one thing that profiling can do is identify the composition of the drug and determine if there are any chemical present which could cause death. It may be possible to identify a possible fatal batch of heroin and prevent users from suffering further ill health by not using it.
The UNODC report (3) outlines the goal of drug profiling as follows ‘When performing impurity profiling work, the analyst’s ultimate goal is to obtain profiles of the major and minor components in formats that allow him/her to use the data as a comparative tool for the purpose of locating other samples having similar profiles’.
The reality is that individual profiling and matching is a complicated analytical procedure with depends on a wide variety of factors. ‘When a drug is manufactured, separate and discrete “batches” of materials are usually processed at any one time’ (6). It is even difficult to match different batch samples from the same lab due to the variety of manufacturing conditions. Since the manufacture is carried out in clandestine labs where reproducibility of conditions is not a priority different batches will have different profiles. This may be due to different solvent used, variation in cutting agents or difference in raw ingredients.
Another problem in profiling batches is that it is seldom that large consignments are produced from the one source, there may be numerous different laboratories involved. Thus resulting in different profiles with the same batch.
The profiling of heroin is generally a two step process (7),
characterization of the sample
Followed by interpretation of the results.
The complexity of heroine samples can be seen in the tables in Appendix 1I. The presence and concentrations of these major and minor constituents varies greatly from sample to sample.
Either one of the following four techniques can be used in the characterization stage
High Performance Liquid Chromatography
Trace element analysis
Note 1, 2 and 3 are the predominant techniques used .
Gas chromatography - GC
GC is the traditional technique used for heroin profiling. The technique is used to quantify the alkaloids present in the sample as well are adulterants. The main advantage of GC is its speed and high resolution (7). Detectors tend to vary but the most popular one is the Flame Ionisation Detector (FID).
The main disadvantage with this technique is that it does not have the sensitivity to detect the trace constituents. Another disadvantage with GC is that the sample usually required a pre-analysis step, derivatisation before injection. The analysis of compounds that are degradable by high temperatures, highly polar, or non-volatile can also be problematic by GC.
The coupling of GC to a Mass spectrometer MS detector has greatly enhanced this technique. GCMS offers higher sensitivity and it is possible to determine unknown compounds in the seized heroin sample (8),
In the illegal manufacture of heroin a number of acidic and basic impurities are formed. The identification of these impurities can lead to information on the manufacturing process used. A GCMS study (9) in which over 500 heroin samples were analysed for outlines how heroin can be classified based on the presence or absence and the relative rations of these compounds. The limits of detection for the impurities were reported to be at the 10-7 relative to the total morphine concentration in the sample.
A further advancement in the technique of GCMS is the use of Isotopic abundance (isotope ratio mass spectrometry (IRMS)). In this technique the ratios between the isotopic abundances of stable isotopes – C12/C13 or N15/N14 of the major constituents are monitored. This technique is most useful is determining the geographical origin of the sample as the variations in the isotope ratios can be related to specific growing conditions of a particular region (10,11)
High Performance Liquid Chromatography
HPLC has been used for many years to characterise seized heroin samples (12,13he detection system most commonly used is UV. Alkaloid impurities can be detected down to 1% of heroin content and minor alkaloids and adulterants can be detected at levels of 0.1% relative to heroin content (12
A much more power technique is the used Mass spectrometry detector coupled to liquid chromatography LCMS. This allows for high sensitivity and selectivity for all compounds in the sample. (14. This technique allows for the highly selective and sensitive detection of many of the targeted solutes in seized heroin. A detection limit as low as 10−6% w/w was reported in this study.
Electrophoresis is a technique used for separating molecules through migration on a support medium while under the influence of an electrical charge. The first use of CE for forensic analysis was demonstrated in 1991 (15). This study describe the use of CE in the analysis of illicit drugs in synthetic mixtures.
The CE method has a number of advantages of the HPLC method, it gave better resolution with significantly faster analysis times – 12 min v 29 min.
The acidic and neutral impurities in heroin can also be quantified by CE method The detection system used in this study was fluorescence detector (16).
A recent study (17) describes the use of a relatively new CE technique capillary electrochromatograohy CEC to analyse 10 different drugs of abuse. This new technique combines the advantages of the high speed and efficiency of CE with the high selectivity and increased sampling loading of HPLC. This study concluded that this method offers many advantages over the traditional HPLC, these include fewer costs, minimal consumption of solvents and samples and shorter analysis times.
Since 2003 The US Drug Enforcement Administration (DEA) uses a capillary electrophoresis (CE) method in its heroin origin determination programme (15). This replaced the HPLC method with was previously used
Trace Element analysis .
The profiling of seized samples for inorganic impurities is also used. Two general method are employed;
Atomic adsorption AAS
Inductively coupled plasma – mass spectrometry
Typical elements analysed using AAS are Cd, Ca, Cu, Fe, Mn and Zn (18)
The Calcium in the sample was due to the addition of adulterants and the Iron was a component in the metal containers used in the extraction procedure. AAS has the potential to link sized samples to other batches and to specific laboratories .
The ICP_MS technique is a fast , sensitive and precise technique for the analysis of inorganic elements.
Two studies (19,20) have used ICP-MS in the analysis of heroin seizures for large numbers of elements, 35 and 73 respectively. The results from both studies indicated that the technique is a reliable and sensitive method and offer the advantage of fast multi element analysis. Both studies reported statistically differences and similarities between samples and showed the possibility to use this method to identify the geographical origin of the samples.
The main disadvantage of ICP-MS is that it is expensive and required a high level of expertise.
Interpretation of Results.
Each of the above methods generally result in large quantities of data been produced. Computer techniques for the handling of large data sets are generally employed to process the large amounts of data generated. ie chemometrics.
The first reporting of advanced statistical technique been used for heroin profiling was reported by 1998 (21). Chemometrics were used to assign a country of origin to seized heroin samples. Seized samples from known origins were analysed and the results were statistically analysed . The method had a success rate of 83% in determining the country of origin. Since then chemometrics techniques are routine in the interpretation of results from profiling (22).
A statistical method using likelihood ratios for ‘unknown’ samples is described is also used in profiling (23) This study outlines how Bayes Theorem can be applied to identify heroin samples from the 4 different geographical regions The results for origin differentiation of 10 heroin samples grouped into different regions and their acetylating agents were reported as being satisfactory.
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