Omar KarzounMs. Lara MasriChemistry 201 honorsJanuary 23, 2018Paper Chromatography As a student,one of the worst incidents that might happen to me is that a glass of water orcoffee would fall into my paper that I would be using to study for the finalexam. Scientists provided these students with a very helpful process that mightmake this horrible incident a little more fun.
Chromatography is a scientific methodin which different mixtures are separated from each other based on theirattraction with the mobile and stationary phase. This would therefore lead topart of the substance to be closer to the mobile phase while the rest moved alittle bit further into the stationary phase. This scientific process hasseveral real-life applications, that might be even used in desperate situations.
There are several distinct types of chromatography, which include gas, liquid,thin-layer, paper and much more. This research paper will be only focusing onpaper chromatography, as out of the types stated above and much more, paper chromatographyattracted my attention the most. As the amount of times I recall spilling water,oil, coffee, or any drink in general on my worksheet is massive and I willfinally gain something from spilling on my paper by having some fun andidentifying the several compounds that make up my drink. Out of most other chromatographytypes, the paper chromatography method is one of the least expensive and mostrapid, efficient and productive types out of them all. This type of chromatographyis used for identifying the compounds that make up the mixture, which relatesto my second point which is the fact that compounds may be discovered as well. Inaddition to that, such as investigation #10, chromatography could be used tosolve a crime case or any investigation in general.
Paper Chromatography likemost other types of chromatography, depend on a liquid or gas mobile phase whichcalled also be refereed as the solvent and a solid or liquid stationary phase,where the substance investigated will be supported by. Paperchromatography is considered to be one of the easiest if not the easiest chromatographytechniques, as it starts by pouring a small amount of the mobile phase into thesolvent, then a small dot of one or more substances would be labelled almost atthe bottom of the filter paper, or the stationary phase. More than one substancescould be added to compare two different mixtures’ polarities and their intermolecularforces strength.
After drying the paper out for a while, place it into thebeaker with the mobile phase, but make sure to not make the dot on the filterpaper interact with the solvent. Close the beaker with a lid to create a moreaccurate lab as a small distance difference may play a critical role in forexample identifying the compound or differentiating between the two different compoundsfrom each other. When the mobile phase reaches the top of the filter paper,remove it and make it dry for a little while. Make sure to mark where thesolvent stopped in order to be able to calculate its Rf value, which iscalculated by dividing the distance moved by the substance over the distancemoved by the solvent. As stated above, paper chromatography and most othertypes of chromatography as well help solve cases involving clues left behind,where the substance could be separated to its pure self to identify who the criminalis. For instance, Officer O’Melveny found a note left after the crime scene whichhad the word DIE written on it. It was written with a black pen and when theentire building was searched, 5 different black pens were found. After givingthese materials to the detectors, they used paper chromatography to find whichpen matches the pen used to write the note with.
Out of the 5 pens, two of themwere insoluble, meaning they didn’t dissolve in water, whereas the note wasable to dissolve in water, therefore, two out of the five men can easily beeliminated. The three remaining pens were different than each other, the firstpen’s dot didn’t move very far away from its staring point, and it was composedout of 3 distinct colors with a small Rf value. However, the second pen didmove quite a distance but didn’t move very far, therefore it had an average Rfvalue with only 2 separate colors. So had the third pen which had its dot movevery far away meaning it had a big Rf value. When the same process was donewith note found from the crime scene, the detectors were able to match the secondpen with the paper in which both moved to almost midway to the end having an Rfvalue of approximately 5.0 and only had two detached colors instead of three.Therefore, after finding the pen used, the detectors used the fingerprints leftto identify who was the user of the pen which therefore makes them able to findthe killer.
Allin all, it is clear how significant the role of chromatography or even chemistryin general is in our real-life world and not only in labs. As in this case, chromatographywas able to determine the killer or the criminal in general of a crime sceneusing only clues left on the floor and lab tools as well. I personally feellike there will be, in the future, much more discoveries, techniques orconcepts in general that will be used more that are related to chemistry thatmight just be able to save someone’s life or turn a very difficult task into aneasy five-minute thing to do. Scientists just have to take into considerationthe problems humans face in general and attempt using scientific concepts tosolve these cases.
Bibliography ausetute. 2012. Paper Chromatography. April 1. Accessed January 24, 2018.
https://www.youtube.com/watch?v=gpFb635N2wo. n.d. Chromatography Crime Scene Evidence . Accessed January 24, 2018.
pdf. 2018. Uses of Paper Chromatography. Accessed January 24, 2018.