Een klein stukje uit de dissertation van T.M. Brunt:
Qualitative and quantitative analyses of the drugs samples that have been sent to the DIMS Bureau were performed in the laboratory of the Delta Psychiatric Hospital (Deltalab, Poortugaal, The Netherlands), which specializes in analyzing drug samples. A set of robust analytical methods was used to identify known and unknown components, to quantify and classify them. After crushing and homogenizing the sample, three separate analytical techniques were used.
First, thin layer chromatography (Toxilab®A) was performed for identification.
Subsequently, the quantification of the main components (e.g. amphetamine, metamphetamine, 3,4-methylene-dioxyamphetamine (MDA), 3,4-methylene-dioxyethylamphetamine (MDEA), N-methyl-a-(1,3-benzodixol-5-yl)-2-butamine (MBDB), caffeine, cocaine and heroin) was performed with gas chromatography - nitrogen- phosphorous detection (GC-NPD).
In case of any discrepancies, or trace amounts requiring quantification, a gas chromatography-mass spectrometry (GC-MS) method was introduced as the tiebreaker. This generally needed to be done in approximately 10% of the samples. GC-MS (Varian Saturn 4D, Varian Medical Systems, Houten, The Netherlands) conditions were similar to GC- NPD and substances were identified full scan (EI) with the NIST-library. GC-MS was also used for quantification of certain uncommon substances (e.g. γ-hydroxybutyrate (GHB), γ-butyrolactone (GBL), para- methoxyamphetamine (PMA), para-methoxymethamphetamine (PMMA), ephedrine, ketamine and lysergic acid diethylamide (LSD)). In exceptional cases, identification was performed using advanced GC-MS and nuclear magnetic resonance (NMR) spectroscopy structural analysis (e.g. 2,5- dimethoxy-4-bromophenethylamine (2C- B), 2,5-dimethoxy-4- bromoamphetamine (DOB) and 4-methylthioamphetamine (4-MTA)).
Hieronder een stukje uit TEDI - Guidelines for Drug Checking Methodology:
Flow-chart van de algemene procedures die doorlopen worden:
Gas Chromatography/Mass Spectrometry (GC/MS)
The description of this method comes from the experience of the Drug and Information Monitoring System (DIMS), located at the Trimbos-Institute in the Netherlands. This procedure is validated according to the principles described in ISO 15189.
The Drug and Information Monitoring System (DIMS) was established in 1992 to prevent serious health problems that could arise as a consequence of the consumption of illicit drugs. To this aim, drugs are chemically analyzed by a sub-contracted laboratory which, until 2009, was the Deltalab Laboratory in Rotterdam. From then on this service has been provided by the DSM Resolve Laboratory in Geleen, The Netherlands.
DSM Resolve analyses a fixed amount of drug specimens with a yearly budget. All extra analyses and as- sociated costs are billed separately. The service contract includes: weekly chemical analyses, reporting back to DIMS, feedback, and all material costs associated with the analyses. The agreement also stipu- lates that intellectual ownership of the drug data belongs to DIMS and that nothing concerning this data may be reported without prior consultation. The laboratory applies proprietary analytical methods.
The time elapsed between injection and elution is called the "retention time" (RT). RT helps to differentiate between compounds. However, RT is not always a reliable parameter to determine the unique identity of a compound. If two drug samples do not have overlapping RTs those samples are different substances. Identi- cal RTs for two drug samples do not, however, exclude the possibility that they are in fact different sub- stances. Potentially thousands of chemicals have the same RT, peak shape, and detector response. Consequentially, it is essential to couple GC to mass spectrometry (MS), collectively termed GC-MS.
MS identifies substances by impacting molecules with high energy electrons, this results in their fragmentation into ions with different masses and electric charge (other forms of ionization are also possible, this one is the most common and known as electronic impact). Ions are accelerated through a magnetic field; differences in mass and electric charge determine their speed and the time to reach the detector. The proportion between ions of different masses for a given compound defines its mass spectrum, which is unique for the compound concerned. The intensity of ions is proportional to the amount of a given compound present in the sample. Therefore, the mass spectrum combined with the RT allows the indisputable qualitative identification of compounds while intensity of fragments of ions at this RT allows its quantitation. Mass spectra observed in a given sample are typically compared with computerized (or printed) libraries of reference for the identification of compounds. Mass spectra for psychoactive substances and other drugs are available to the laboratory through relevant chemical and toxicological libraries, either through contacts with forensic institutes or through international connections with the EMCDDA and the Early Warning System.
Summary of analytical characteristics:
Benefits: combining GC with MS is ideal, making qualitative and quantitative determination possible.
Results are highly accurate and small amounts of drugs are needed for analysis. Through the use of an
adequate library of mass spectra it is possible to identify the substances in a sample.
The costs of the technique for the association: the contract with the laboratory is for a maximum of 100 samples per week, this includes LC-DAD quantification of 10 frequent substances and GC-MS of all substances. Special requested analyses and quantifications of unknown or rare substances are excluded.
For a quantity of 100 drug samples, the cost is 31 € per sample. The extra requested analyses cost 82 € per sample. This low price for each sample is linked with the high number of samples analyzed for the laboratory. In other conditions, the price would be higher.
Reliability of results: it is a highly reliable and reproducible method, which has been previously well
described and documented by many groups (forensic, SAMHSA, NIDA, DEA, etc.). It is the golden