Definitive Identification of Amphetamines

GC -MS is the preferred method for the identification of amphetamines. The discussion below centres on the analysis of amphetamine itself, although the same principles can also be applied to other members of this class of drug. However, there are a number of problems associated with the gas chromatographic analysis of amphetamine. Being highly polar in nature, this compound is liable to poor chromatographic behaviour and tailing if the analytical instrument is not scrupulously clean (Figure...

Quantification of Psilocin and Psilocybin by HPLC

HPLC can conveniently be used to quantify psilocin and psilocybin in drug samples. As a quantitative method, it has a number of advantages over GC-MS. For example, HPLC does not require any thermal stability of the drug and hence derivatization is not needed. This eliminates the problems associated with ensuring complete derivatization and the risk of sample contamination. Although a number of reported HPLC analytical methods can be found in the literature, we will illustrate the procedure...

Quantification of Amphetamines

Free Base Amphetamine

Due to the nature of the compounds being considered and the need for derivati-zation, GC-MS is not considered the best technique for sample quantification. What are the difficulties associated with quantification following deriva-tization There are a number of difficulties encountered with quantification after employing derivatization. These include the fact that we are now considering another analytical step, with the concomitent increase in cost and time of each analysis. In addition, because...

Identification of Psilocin and Psilocybin Using Chemical Analysis

Due to the potential difficulties involved in using morphological characteristics, chemical analysis is often employed to demonstrate that the material is controlled. However, such an approach will not lead to identification of fungal species. Why will chemical analysis not lead to identification of fungal species Such identification is not possible because the presence of psilocin and psilocybin is observed in many different species of this genus. Coupled to this, it is also not possible to...

Impurity Extraction and Sample Comparison

Each route of synthesis will result in an impurity profile which can be analysed. Unlike cannabis, heroin and cocaine, the impurities are present in very low concentrations and need to be extracted from the amphetamine matrix. Liquid-liquid extraction (LLE) and solid-phase extraction (SPE) have been most frequently applied for this purpose 13-16 . Of these, LLE is currently the most widely used technique. In addition, there are attempts being made to develop the method so that it can be...

Presumptive Testing for LSD

The presumptive tests for LSD involve a fluorescence test and a chemical test. 3.2.3.1 Fluorescence Testing for LSD One of the properties of LSD that can be exploited during the identification process is its fluorescence. In such a test, the original dosage form, or a drop of the methanolic extract from the dose form, is placed on a filter paper and allowed to dry. The material is then observed under long-wavelength UV light (360 nm). If LSD is present, blue fluorescence will be observed. If a...

TLC of Barbiturates and Benzodiazepines

Having carried out presumptive tests for these drugs, if a positive result occurs, then further analysis is required. The next phase in the analysis is TLC. Methanol solutions of the drugs can be used, while the standards employed should include the drug which has been suggested through physical examination of the dosage form. However, these drug groups also present some special difficulties in their TLC analysis - these are discussed below. 9.2.3.1 TLC Analysis of Barbiturates In this case,...

Duquenois Levine Reagent for Cannabis Products

The components of this reagent are 2.5 ml of acetaldehyde and 2 g of vanillin dissolved in 100 ml of 95 ethanol (1), concentrated hydrochloric acid (2) and chloroform (3). Testing is carried out as follows. Five drops of solution (1) are added to the material under investigation, which has previously had a drop of ethanol added to it to solubilize the cannabinoids, and the system shaken. Five drops of solution (2) are then added and after shaking again, 10 drops of solution (3) are added. The...

Comparison of Cocaine Samples

The profiling and comparison of cocaine is a complex process, the details of which are beyond the scope of this present book. However, it is useful to consider the compounds which might be present in a sample and how they arise. These include the cocaine content itself, both from the drug and the ecgonines, and other by-products from the process of cocaine synthesis, along with various breakdown products. In addition, there is nor-cocaine, the N-demethylated product which arises as a...

Quantification of Cocaine by UV Spectroscopy

This technique works particularly well if the cocaine is mixed with sugars, from which it can be easily separated by dissolution. Calibration standards are prepared, in methanol solution, at concentrations of 1.0, 0.5, 0.25, 0.125, 0.0625, 0.031 25 and 0.0156 mgml-1, using serial dilutions. A UV spectrum of a holmium filter is first measured to confirm that the instrumental set-up is performing satisfactorily. 0.50 1.00 1.50 2.00 2.50 3.00 3.50 Cocaine (mg ml-1) 0.50 1.00 1.50 2.00 2.50 3.00...

Identification of Herbal Material

Botanically, Cannabis sativa can be identified on the basis of its gross morphological features and, more importantly, by the presence of microscopic structures on the surface of the plant, namely the trichomes. At the macro-morphological level, it has a square stem, with four corners, and has palmate leaves with serrated edges. These are the characteristics with which most people are familiar. Microscopically, three types of trichome are observed, namely the glandular tri-chomes (Plate 4.1),...

Scott Reagent for Cocaine

This is a modification of the previous test, with the reagent consisting of a 2 (wt vol) solution of cobalt isothiocyanate in water, diluted with an equal volume of glycerine (1), concentrated hydrochloric acid (2) and chloroform (3). Testing for cocaine is carried out as follows. A small amount of the material is placed in a test-tube and five drops of component (1) added, when a blue colour will develop if cocaine is present. One drop of concentrated hydrochloric acid (2) is then added and...

Identification of Other Materials

If the morphological characteristics of Cannabis sativa are not all present, or if they have been destroyed, in, for example, resinous material or material that has been smoked (Plate 4.4), it is necessary to identify the material through its phytochemical content. This is also true for hash oil, and all three materials will be considered in the following sections. This involves the identification of the principle drugs which characterize the plant, namely A9-tetrahydrocannabinol (THC), CBD and...

Quantification of Cocaine by GCMS

This method relies on the response of the detector being in direct proportion to the concentration of drug in the sample being evaluated. A series of standards of known concentrations is prepared and analysed, with each analysis being separated by a blank. Why should each sample be separated by a blank in the analytical process The same solution system must be used to prepare both the standards and the samples. Why are internal standards necessary Why is there a requirement to use the same...

Presumptive Tests for Cocaine

There are a number of presumptive tests for cocaine available from the literature. These are described below. 6.3.1.1 The Cobalt Isothiocyanate Test Although there are several presumptive tests available for cocaine and related compounds, none alone is specific to cocaine itself. A very simple test for cocaine is the addition of the material under investigation to a 2 (wt vol) solution of cobalt isothiocyanate in water. The presence of cocaine and related alkaloids results in a blue colour...

Definitive Identification of Cocaine

GC-MS is routinely applied to the identification of cocaine. This is because the technique is both sensitive and of very high resolution. However, this method can also be used on simple mixtures. Trace samples should be obtained by swabbing the surfaces to be examined and subsequently processing the swabs by eluting the drug using methanol or ethanol. Where bulk samples are to be analysed, the sample should be thoroughly homogenized in preparation for this. Derivatization is frequently used and...

Analytical Sequence Bulk and Trace Sampling Procedures

Prior to the process of identifying whether or not a material contains cannabis or its products, a decision must be made as to whether the sample is a bulk or a trace sample. A bulk sample can be defined as anything that can be seen (herbal material, resin or oil), while a trace sample, in terms of cannabis, can be loosely defined as one which would easily be contaminated. Trace samples might be present, for example, on the surfaces of scales used to weigh cannabis materials, the surfaces of...

Identification Quantification and Comparison of Khat Samples

There are few reports in the literature of analyses of material from C. edulis and the only known prosecution for the production of cathine and cathinone from Khat (R. vs. Farmer, Lewes Crown Court, 1998) was unsuccessful 5 . Nevertheless, it is still necessary and useful to understand how to identify, quantify and compare such materials. 7.2.1.1 Identification and Quantification of Khat Basic forensic science principles should be adhered to when carrying out the analysis of a Khat seizure....

Thin Layer Chromatography

Prior to the use of any further method for the analysis of the material and identification of cocaine, the latter must be extracted. For powdered samples, which have been thoroughly homogenized, a 1 mgml-1 solution in methanol will suffice. For herbal material, the situation is rather more complex if the problems associated with extraction of chlorophyll, etc. are to be avoided. One study, where methanol and ethanol alone and in the presence of either diethylamine or ammonia were used,...