'Crime and Dye Lab Essay\r'

'Light is usu all in ally viewed as a result of the heating of a substance. The higher the temperature at which the substance is heated, the greater the vibrations that lead to certain fallibleen intensity given off by the molecule. It is this equivalent theory that suggests why steel flares red sweltry when heated to high enough temperatures. The extremity of light emissions washbowl also be induces through separate representation.\r\n1\r\n oneness of such agency termed fluorescence drop deads when a substance git be induced into big(a) off light is through absorption of a photon through light or other means of radiations. During this carry through, electrons are excited from their standard state. The electrons jump from their highest untenanted orbital (HUMO) into a certain level of the untenanted orbital (LUMO). As the electrons loose energy, they fall gumption to a lower orbital, thus emitting light.\r\n1, 2\r\nDuring the litigate leading to fluorescence, a certai n change could occur during the excitation of the electron, changing the spin of the electron as it gets excited. This change has to be undone as the electron goes back to its standard state. The emitting of light in this carry through is known as phosphorescence. The process of fluorescence is much meteoric than phosphorescence. This is due to the fact that in phosphorescence, the electron has to permit an extra step of undoing its current spin. This process is thermodynamically unfavorable compared to fluorescence.\r\n1, 2\r\nThe last means by which light could be generated is through chemiluminescence. In such a case a chemic reaction occurs, causing an excitation of the harvest-home. As this product decays into its standard state, light is emitted. This form of luminescent is divergent from the previous two in the sense that no absorption of light is required to induce the glisten. The glow results from the product of the chemical reaction having to be in an exited state or of higher energy. 1\r\nThe process of photon absorption and emission is certain a phenomenon that plays a vital role in our society. such vastness is expressed during rescue operations, where victims can be substantially found due to waving of a fluorescent material at night. It is evident that fluorescence becomes important when a thermally induced light emission is deemed impossible.\r\n1, 2\r\nSeparation techniques were concepts that were important in the course of this audition. One of such is through the means of UV Vis Spectrophotometer. The constituents of sign dyes can be determined using a spectrophotometer. By placing the dyes in the spec, mixed wavelength peaks will be obtained. These peaks can be used to find break the constituent airs making up the dye.\r\nanother(prenominal) important form of separation used during this experiment is chromatography. Chromatography utilizes the differences in polarity of substances as means of separation. Such is the case of a crime lab involving the determination of a compose used in composition on a piece of base. If a pen out of tetrad is used to write a note, the feature pen can be sight using chromatography. The dyes of all intravenous feeding inks and the unknown region ink can be obtained. This ink can be run through a chromatograph column, allowing a outcome to run above the ink dyes, carrying them along.\r\nAfter a certain point the RF values of all the inks can be used to detect the particular ink. The RF value is the distance the ink travels carve up by the distance travelled by the solvent. The ink with the same RF value as the unknown is the same ink used. Chromatography has a wide float of use. It use can be stretched from this as it can also be used to indicate the percentage amino erosives found in various proteins. The protein can be run through the column, resulting in the various amino acids that make the protein, to be separated.\r\n1, 2\r\nMaterials and Methods (Summar ized from laboratory Manual) 1\r\nProcedure\r\n* Phosphorescence\r\nTwo different polyaromatic acids, 1- naphthoic acid and 4-biphenylcarboxylic acid, were obtained and drops were added unto two filter paper. The solvents heated to dryness for 11 minutes using a hot central office on low heat. The filter papers were indeed placed under long and short wavelength ultraviolet illumination lamps. observation of the intensity and duration of glow were recorded.\r\n* Fluorescence\r\n clean water was poured into a beaker. Long and short wavelength UV lamp was shined above the beaker. Observations were recorded. Now, a beaker of water was taking to the UV lamp and was shined at the beaker. Observations were recorded. After, 3 drops of concentrated fluorescein answer was added into the beaker. The UV lamp was shined above the beaker and observations were recorded.\r\n* Chemiluminescence\r\n2 mL of Tekrakis-(dimethylaminoethylene) was added into a microscopical footrace tube. This men tal testing tube was interpreted to the UV lamp and shined at. Observations about the intensity and duration of glow were recorded.\r\nAfter, 1 mL of luminol in DMSO was added into five test tubes. Now, in distributively test tube fluorescein, rhodamine, rubrene and perylene solutions were added in 4 four of the five test tubes. Observation of the color of from individually one solution was recorded. At this point, 1M NaOH was added into each test tube and was wherefore shined with a UV lamp. Further observations were recorded.\r\nFinally 1 g of Al2O3 was added into four 250 mL Erlenmeyer flask. This was mixed with 1 mL of 3% H2O2. In each flask, perylene, tetracene (2,3-benanthracene), 9,10-Dipehenylanthracene, and rubrene were added respectively. Now, 1 mL of oxalic chloride was added in each flask and swirled. Observations were thusly recorded.\r\n* Crime laboratory\r\nA water bath was heated and hold at 650C. Now, scribbles were made on papers from each of the four pens. The paper with each scribble was crop into small pieces and placed into a marked test tube. Also, a scribble of an unknown pen was obtained. The paper was also cut into small pieces and placed in a test tube. 2 mL of methanol was added into each test tube and was placed in the hot bath for 5 minutes. The test tubes were allowed to cool, the color of the inks were recorded and poured into five cuvettes. Using a UV-Vis spectrophotometer, the wavelength peaks and absorbance of each ink solution were recorded.\r\nFour of the five dyes were then poured into new marked test tubes. The solutions were then boil for 14 minutes until the there were less than 1 mL. The solutions were allowed to cool. Now, a 250 mL beaker was obtained. In it was added a small amount of methanol (less than half a curium in point). A filter paper was then obtained and cut towards the end (B.1). This was placed at the brass of the beaker. Finally, an alumna plateful was cut in the proportion of 8 x 4 cm. A stemma was drawn at a 1 cm height using a pencil. In this line, drops of the four inks were spotted. This plate was then leaned inside the end of the beaker (B.2). The plate was left in the solvent until it reached ¾ of the way up. The height the inks and solvent reached up the plate was recorded.\r\n'