IntroductionGas chromatography with massspectrometry (GCMS) is an analyticalmethod used to identify different substanceswithin a given sample. This method ofanalysis is extremely common in manyrealms of chemistry, notably in forensicstudies and identification of drugs,explosives, and many other compounds.GCMS works by first injecting asample which is then vaporized and sweptonto a chromatographic column via carriergas. The sample flows through the columnand any compound containing a chemical ofinterest is separated by relative interactionwith the column coating and the carrier gas.The chemicals of interest then transferred tothe entrance to ion source where compoundseluting from are converted into ions. Theions are then filtered using a mass analyzerwhich separates the positively charged ionsaccording to various mass related propertiesthat depend upon the analyzer used. Afterseparation the ions enter a detector wherethe output is amplified to boost the signal tosend to a computer. The data recorded onthe computer was converted from electricalsignals to a mass spectrum.In this experiment six compounds: o-dichlorobenzene, 2-bromo-2-methylbutane,benzene, p-xylene, 4-methyl-2-pentanol, anddecane; at 200 ppm in a hexane solvent areanalyzed and used to identify the unknowncompound provided.Experimental SectionThe “Chem155_GCMS.M” methodwasloaded, with the following settings: columnIdentification of an Unknown via GasChromotography and Mass SpectrumPreston GriffinDepartment of Chemistry, University of California Merced, Merced 95348, United StatesAbstract:GCMS is a common technique used for identifying the componentsin an unknown solution. This experiment uses GCMS to identify thecompounds present in an unknown solution. This is done by identifying similarretention times and MS peak values in the standards and unknown. It was foundthat the unknown from this experiment contained benzene (3.052 minutes) andto 4-methyl-3-pentanol (5.017 minutes).