Forensic Analysis Essay

When it comes to forensic analysis in the laboratory, there are a few techniques that involve the separation of different substances. Chemical partitioning is an important process in the field of forensic science. The examination of evidence that involve this process help with finding concrete information in a case. If we did not have these techniques, it would be impossible for scientists to tell the differences or similarities between two substances. The forensic analyst must perform these types of examinations in order to figure out if an unknown sample is similar to, or the same as a known sample. Therefore, the analyst will be able to find out if the sample is a certain type of substance.
To my understanding, the meaning of partition is based in terms of the dividing or separation of. According to English by Oxford Dictionaries.com, it is the separation of a

solute between two solvents that will not dissolve or slightly dissolve into each other, using properties such as solubility, ionic strength, or acid/base properties ("partition | Definition of partition in English by Oxford Dictionaries," n.d.). There are a few different types of extractions that are used in analysis, in which the component being tested is kept separate from the matrix. The matrix is where the component was originally found. A liquid-liquid extraction always involves the use of water and must be immiscible with an organic component.
One type of partitioning technique that is used in forensic analysis is called electrophoresis.

This type of method is used in the separation and viewing of macromolecules (Wiley, n.d.). In an investigation process, a forensic analyst can perform this technique to find out if the DNA found at a crime scene is similar to or the same as the suspect's DNA (Wiley, n.d.). Another technique that forensic scientists use effectively is the liquid-liquid extraction method. With this method, drugs can be extracted from biological samples, such as blood, urine, or sweat. A variety of different drugs and metabolites can be obtained through this method. This is one way how forensic analysts are able to separate drugs. In class, we performed a lab for Week 2 which involved the extraction of caffeine from tea bags, which is a metabolite, and this was carried out through the process of the liquid-liquid extraction. This is an example of how forensic scientists apply these tests to real-life analysis of evidence in an investigation. The first part of the lab consisted of the disintegration of caffeine into

water.
Water is the first thing that needs to be used to extract the caffeine from the tea bags, which is an example of solid-liquid extraction. In the second part of the lab, we transferred the caffeine from water to the ethyl acetate solution. In this section of the lab, we were able to separate the top layer and bottom layer of the liquid through the use of a separatory funnel. This is the liquid-liquid extraction process. From this point forward, we extracted the top layer into four test tubes for further analysis into a machine called centrifuge. It uses gravity and high speed to separate liquids or solids. After that, a boiling bath was set up with a watch glass over it. We poured the top layer solution into the glass, little by little, until all of the solution evaporated. The final step is to determine the mass of caffeine and the tea bags to determine the percentage yield.