05-05-2017, 04:56 PM
Within forensic science, the role of the drug section is to demonstrate to a satisfactory level in court, including advocacy, what a substance is and whether or not it contains controlled drugs under current legislation. Doing this to the required level by the court involves conducting a chemical analysis. In addition to determining exactly which drug may be in a given substance (qualitative analysis), further chemical analysis may determine the amount of drug present and, therefore, provide purity of the substance (quantitative analysis).
A drug test is a technical analysis of a biological sample, eg, urine, hair, blood, breath, sweat or oral fluid / saliva, to determine the presence or absence of specified parent drugs or their metabolites. The main uses of the drug test include detecting the presence of steroids that improve performance in sports, employers screening for drugs prohibited by law (such as cannabis, cocaine and heroin) and police officers To detect the presence and concentration of alcohol Commonly known as BAC (blood alcohol content). BAC tests are typically administered via a breathalyzer while urinalysis is used for the vast majority of drug testing in sports and the workplace.
There are a number of steps that a forensic chemist will undertake to analyze a substance. Initially, the chemical will weigh the substance and then take small samples, known as sub-samples, for various analyzes. The next step would normally involve performing color tests on one of these subsamples. These are simple chemical tests that produce distinctive colors that vary depending on the drug involved, if in fact any drug is present at all. The substance is added to a small amount of reagent and any color change taking place may be indicative of the presence of a particular type of drug. This simple test, however, does not specifically identify a drug.
For this, the substance would generally be analyzed by gas chromatography-mass spectrometry (GC-MS). This is a combination technique, which involves two distinct processes. The first one, the gas chromatography, separates the different components that make up a given substance. The substance is vaporized and then passed through a column, the coating of which will be attached to the individual components of the substance with different intensity. Because of this the components will emerge from the column at different times as it is heated, producing a chromatograph. The peaks shown in the resulting chromatogram are proportional to the amount of the substance in the sample that has been analyzed.
The second part of this technique, mass spectrometry, implies that each of the separate components of the original substance is bombarded with a stream of electrons. This causes the component molecules to rupture and ionize. They are then separated by size and load, whose patterns can be considered as fingerprints for an individual component and are used to identify it conclusively.
A drug test is a technical analysis of a biological sample, eg, urine, hair, blood, breath, sweat or oral fluid / saliva, to determine the presence or absence of specified parent drugs or their metabolites. The main uses of the drug test include detecting the presence of steroids that improve performance in sports, employers screening for drugs prohibited by law (such as cannabis, cocaine and heroin) and police officers To detect the presence and concentration of alcohol Commonly known as BAC (blood alcohol content). BAC tests are typically administered via a breathalyzer while urinalysis is used for the vast majority of drug testing in sports and the workplace.
There are a number of steps that a forensic chemist will undertake to analyze a substance. Initially, the chemical will weigh the substance and then take small samples, known as sub-samples, for various analyzes. The next step would normally involve performing color tests on one of these subsamples. These are simple chemical tests that produce distinctive colors that vary depending on the drug involved, if in fact any drug is present at all. The substance is added to a small amount of reagent and any color change taking place may be indicative of the presence of a particular type of drug. This simple test, however, does not specifically identify a drug.
For this, the substance would generally be analyzed by gas chromatography-mass spectrometry (GC-MS). This is a combination technique, which involves two distinct processes. The first one, the gas chromatography, separates the different components that make up a given substance. The substance is vaporized and then passed through a column, the coating of which will be attached to the individual components of the substance with different intensity. Because of this the components will emerge from the column at different times as it is heated, producing a chromatograph. The peaks shown in the resulting chromatogram are proportional to the amount of the substance in the sample that has been analyzed.
The second part of this technique, mass spectrometry, implies that each of the separate components of the original substance is bombarded with a stream of electrons. This causes the component molecules to rupture and ionize. They are then separated by size and load, whose patterns can be considered as fingerprints for an individual component and are used to identify it conclusively.