Investigation 20 used spectroscopy along with stoichiometry to determine how much of cobalt was present in a soil sample. The real world application of spectroscopy is endless but one particular scene where spectroscopy is crucial is its application to law enforcement and forensic investigation. While the type of spectroscopy used is different than that used in the laboratory investigation the same basic principles apply. Spectroscopy in its different forms is used to catch the degenerates and is one science that works to make society a better place. One type of spectroscopy that is particularly useful in forensics is Raman Spectroscopy which applies spectroscopy to the study of ink on paper. The process involves irradiating a document with monochromatic light (light of one particular wavelength) using lasers and observing the scattering, absorption, intensity, and overall interaction of the light with the ink. From this forensic investigators can determine the type of ink from its chemical composition and determine the manufacture (Braz 1.1). The …show more content…
This process is used in forensics because it is so precise, fast, and reliable. The process includes creating a high-temperature plasma induced by a laser, which allows the user to remove a small amount of mass from the subject, known as laser ablation. This ablated mass is then further manipulated to form a high energy plasma containing free electrons and energized ions. Once the laser is turned off, the plasma will begin cooling, which will let the ions return to their natural state. When this happens, they will give off a certain spectra that will allow the user to be able to tell what exactly was in the species they experimented on (appliedspectra.com). This could be useful in determining such substances like what glass is composed of or what type of glass was
Compress the safety bulb, hold it firmly against the end of the pipette. Then release the bulb and allow it to draw the liquid into the pipette.
Forensic Science Introduction: Someone in a restaurant has suddenly fallen ill and a mystery powder has been discovered with the victim. As the chief investigator, your duty is to identify the mystery substance through a lab. In this lab, it will consist of five known compounds and one unknown compound. Your job is to distinguish which one out of the five substances is the mystery powder. To figure out the mystery matter you will have to compare their physical and chemical properties and match them with the appropriate compound.
A common tool that forensic units use is the ultra violet or UV light. Ultra violet light can detect different areas that contain blood that might not be able to be seen in other conditions. Another common tool is the blood reagent test that forensics use on scene. These tests determine if the blood is human or animal. Renee Blake - "The 'Renee Blake'" There are different types of bloodstain patterns that give a sense of what happened at the scene.
Atomic Absorption (AA) Spectroscopy is a quantitative analysis technique that uses the absorption of light through a flame and gaseous chemicals. AA Spectroscopy can be used for a multitude of purposes, most notably finding the concentration of one or a few elements in a compound. AA Spectroscopy can work in two different ways using an open flame and gaseous chemicals or a graphite furnace. Flame AA Spectroscopy works by taking a compound or element and disassociating it into an aqueous solution. The solution is then blown through an incredibly small nozzle which nebulizes the liquid into a very fine mist. The nebulized liquid is then blown through a flame with a very small beam of light passing through it. This light beam detects different elements in the flame and uses the known light absorbance of the element to determine the concentration of the element in the solution. The other form of AA Spectroscopy uses a graphite furnace to heat up and incinerate a sample. A solid compound is placed in the furnace which then heats up to 2000-3000 C effectively atomizing the compound and in the process turning the rest into ash. The light beam is then shot through the furnace as the solid is being heated and subsequently atomized and the machine records the absorbance rate much like the Flame AA Spectroscopy would. The difference between flame and furnace spectroscopy is in the atomization of the sample; because the Flame Spectroscopy uses pressure to atomize the compound, much of the compound is lost when sprayed
Crime scenes are known to have many clues left behind. The obvious would be a the body or bodies, clothing, and sometimes even the murder weapon. While these are great way to solve a case there's another kind of evidence; trace evidence. Trace evidence are small pieces of evidence that are laying around a crime scene. There are many types of trace evidence some of them include metal filings, plastic fragments, gunshot residue, glass fragments, feathers, food stains, building materials, lubricants, fingernail scrapings, pollens and spores, cosmetics, chemicals, paper fibers and sawdust, human and animal hairs, plant and vegetable fibers, blood and other body fluids, asphalt or tar, vegetable fats and oils, dusts and other airborne particles, insulation, textile fibers, soot, soils and mineral grains, and explosive residues. Although these are the most common found elements, they are not the only ones. The Trace Evidence Unit is known to examine the largest variety of evidence types and used the biggest range of analytical methods of any unit. materials are compared with standards or knowns samples to determine whether or not they share any common characteristics. In this paper I will discuss the different kinds of trace evidence and how crime scene investigaros use it to solve cases and convict criminal.
Forensic toxicology is one of the oldest disciplines in forensic science history and dates back hundreds of years. However, the actual understanding and examination of forensic toxicology only dates back for about 200 years. Due to the development of technology, this discipline has been able to progress and flourish.
To understand this week’s experiment one must first understand what a spectroscope is and what it does. With this understanding in hand, one would gain a deeper appreciation for this lab and its intended lesson. “A spectroscope is a device that measures the spectrum of light” (Ball, 2014). More specifically a spectroscope is an instrument designed to split light from different sources into wavelengths. Humans are able to see these wavelengths as different colors. Noting the difference in colors between various light sources, those studying a given light source can identify elements of the light source.
Chemical kinetics is a branch of chemistry that involves reaction rates and the steps that follow in. It tells you how fast a reaction can happen and the steps it takes to make complete the reaction (2). An application of chemical kinetics in everyday life is the mechanics of popcorn. The rate it pops depends on how much water is in a kernel. The more water it has the quicker the steam heats up and causes a reaction- the popping of the kernel (3). Catalysts, temperature, and concentration can cause variations in kinetics (4).
They are not found at crime scenes but used as comparisons to those prints found at crime scenes.
White, P 1992, Crime scene to court: the essentials of forensic science, Royal Society of Chemistry, London, p. 20-33.
According to the graph on amylase activity at various enzyme concentration (graph 1), the increase of enzyme dilution results in a slower decrease of amylose percentage. Looking at the graph, the amylose percentage decreases at a fast rate with the undiluted enzyme. However, the enzyme dilution with a concentration of 1:3 decreased at a slow rate over time. Additionally, the higher the enzyme dilution, the higher the amylose percentage. For example, in the graph it can be seen that the enzyme dilution with a 1:9 concentration increased over time. However, there is a drastic increase after four minutes, but this is most likely a result of the error that was encountered during the experiment. The undiluted enzyme and the enzyme dilution had a low amylose percentage because there was high enzyme activity. Also, there was an increase in amylose percentage with the enzyme dilution with a 1: 9 concentrations because there was low enzyme activity.
Forensic Science, recognized as Forensics, is the solicitation of science to law to understand evidences for crime investigation. Forensic scientists are investigators that collect evidences at the crime scene and analyse it uses technology to reveal scientific evidence in a range of fields. Physical evidence are included things that can be seen, whether with the naked eye or through the use of magnification or other analytical tools. Some of this evidence is categorized as impression evidence2.In this report I’ll determine the areas of forensic science that are relevant to particular investigation and setting out in what method the forensic science procedures I have recognized that would be useful for the particular crime scene.
scientific method for things such as DNA samples from hair and body fluids, fingerprint analyses and
Firearms identification is too often referred to as ballistics. The accurate definition can be referred to as, the identification of fired bullets, cartridge cases or other ammunition components as having been fired from a specific firearm. Due to the firearm being composed of hard metal like a tool, it creates markings on the cartridge components causing it to be more like Toolmark Identification. There are various items of evidence, other than the firearm itself, which the lab will use to aid in the investigation for identifying a firearm, including the wadding for the shell, fired cartridges and casings, and much more.
...ires that the evidence is not altered during the examination so that it can be later reexamined in its initial status by another examiner. There are two kinds of SEM that are valuable for these issues, which include environmental (ESEM) and low vacuum (LVSEM). Both instruments are operated differently; however, they both allow examination without any preparation that would modify the sample. Validation means that it can be demonstrated in court that the microscope was in working order and the methods used while in operation were acceptable (Kruesemann, 2008). The SEM has many additional uses including examining bullets and studying tool marks made by firing pin impressions. This information will allow forensic scientists to determine the kind of gun that was used. The SEM has proved to be an excellent device for forensic investigations (Firearms Tutorial, n.d.)