Chromatography Lab Report

Chromatography Lab ReportGC-1 ( accelerator Chromatography) es severalise 1, 2, 3 4 experimentation 1- aim of fermentation alcohol nub of a gargle victimisation an versed precedentExperiment 2- Determination of oxygenates in gasolineExperiment 3- qualitative and denary depth psychology of BTEX (Benzene, methylbenzene, Ethylbenzene and Xylene)Experiment 4 Determination of volatile compounds by headspace analytic thinking indigotin KumarIntroduction TheoryThe experiments performed in this lab were based on Gas chromatography specifically gas-liquid chromatography. This technique involves a sampling being vapourised and injected onto the head of the chromatographic column. The seek is transported through the column by the flow of neutral, gaseous busy phase. The column itself contains a liquid stationary phase which is adsorbed onto the surface of an inert solid.GC Schematic diagram (http//teaching.shu.ac.uk/hwb/chemistry/tutorials/chrom/gcdiag.gif )In Experiment 1 the f ermentation alcohol content in a mouthwash was determined. This was done by utilise an infixed example of butanol. and so, ascendants of internal stallingard with outlander solution and fermentation alcohol were do and injected into the GC. The playing fields obtained for each compound were hence use to bet the % alcohol in the assay.In Experiment 2 ethanol content in gasoline inter mixture was cypher utilize a regular trim down of ethanol made with unmixed ethanol. The gasoline mixture was extracted with weewee to extract the ethanol in it for further abbreviation by GC. The GC method is used industrially to find ethanol content in gasolines, plus oxygenates like butyl vinyl ether that fag end contaminate drinking water..In Experiment 3 qualitative analysis of BTEX (Benzene, methylbenzene, Ethylbenzene and Xylene) was performed by injecting pure solutions of these compounds in GC. The belongings times obtained were put down for each. In the second part, m onetary standard solutions of methylbenzene and xylol were made and standardisation curves were made for each. Next, the unknown sample of BTEX was injected to GC. The retentivity areas obtained were recorded and substituted in compares of standard curves to find the actual content of methylbenzene and xylol in sample.In Experiment 4 the technique of headspace analysis was used to determine the volatile compounds in a contaminated blemish sample. The soil sample was also deliberately contaminated with methylbenzene and xylol and placed in a vial for 10 minutes. Then using a syringe, the headspace was sucked and injected to GC for performing a qualitative analysis (the belongings times of BTEX from Experiment 3 were used).GC is continuing to be used in a number of fields as an analytical brute due to certain advantages likeShorter run timesGreater sample throughputCheaper columns mellower signal to noise ratioLower bleed (thinner films)High resolution power compared to others. Complex mixture can be fixed into its components by this GC method. The separation, purpose and identification of many compounds withnegligibledifferences in boilingpoints is thinkable by this technique.Sensitivity in detection is very high with caloric conductivity detectors. One can detect upto tip centigrade ppm, while firing detectors, electron capture and phosphorus detectors can detect ppm, parts per one thousand thousand or picograms respectively.(http//www.sge.com/support/training/fast-gc-analysis/advantages-/-disadvantages-of-fast-gc)Some industrial applications of GC involveIdentification and quantification of ubiquitous pollutants in the environment analysis of various classes of unconquerable organic contaminants in air, water, soils, sediments and biotaGC Analysis of AntioxidantsDetermination of ethanol in gasolineAnalysis and quality assessment of alcoholic beverages Quantitative and qualitative assessment ofAlcohols in bloodAromatics (benzene, toluen e, ethylbenzene, xylene)Flavors and FragrancesPermanent gases (H2, N2, O2, Ar, CO2, CO, CH4)HydrocarbonsPesticides, Herbicides, PCBs, and DioxinsSolvents(http//www.med.cmu.ac.th/dept/vascular/alcho/ query/res_out/Application%20of%20gas%20chromatography.pdf)As we can see, the varied applications of GC in industry and its advantages over other methods, performing of these GC experiments is industrially justified.Experiment 1- Determination of ethanol content of a mouthwash using an internal standardProcedureThe instrument was set to the following parametersInjector temperature cc course CDetector temperature 250 pointedness COven temperature 80 horizontal surface Cattenuation between 4 and 16 carrier gas stuff 8-10 psiFID range 1Valve Split 1 on weaken the unknown ethanol sample and mouthwash provided with water in a 110 ratio. 10 ml of each was diluted to 100 ml in volumetric flask.Next, ethanol standard solution and butanol (internal standard) (each2 ml to 100 ml water) were m ade.Equal volumes of ethanol and internal standard were mixed. And equal volumes of sample solution and internal solution were made (each 5 ml).Now, three injections (0.3 uL each) were made of each of these solutions into the GC.From the chromatographs, the % of alcohol in sample were calculated.Observations, Calculations and Results puppet GC SST pecker settingsInjector temperature 200 degree CDetector temperature 250 degree COven temperature 80 degree CAttenuation between 4 and 16Carrier gas push 8-10 psiFID range 1Valve Split 1 onSolution storage time flyer areaButanol1.4005452.57 neutral spirits0.7003607.3Butanol (I.S.) + Ethanol1.400-Butanol (I.S)0.700-Ethanol2226.71341.9Solution retentivity time gratuity areaInt. Stan + abstruse ethanol sampleInt. Stan- 1.383Unknown ethanol Sample- 0.683 (Ethanol)2878.8874.3Int. Stan + MouthwashInt. Stan- 1.383Mouthwash 0.683 (Ethanol)3373.42079.5Using the formula,RsplRI.S. = CsplRstd CstdRI.S.where, R=response ( spinning top area) spl=samp le, I.S.=internal standardC= ConcentrationFor Unknown ethanol sample,we have, Rspl = 874.3, R I.S= 2878.8, Rstd = 1341.9, R I.S. = 2226.7Cstd = 2 % (From observation circuit card 1 2)Putting these assesss in equation,874.3 / 2878.8 / 1341.9 / 2226.7 X 2 = CsplOn solving we get, Cspl = 1.00 %For mouthwash,we have, Rspl = 2079.5 , R I.S= 3373.4, Rstd = 1341.9, R I.S. = 2226.7Cstd = 2 % (From observation table 1 2)Putting these values in equation,2079.5 /3373.4 / 1341.9 / 2226.7 X 2 = CsplOn solving we get, Cspl = 0.98 %So, % alcohol in Mouthwash is = 0.98 % in Unknown ethanol sample = 1.00 %Experiment 2- Determination of oxygenates in gasolineProcedureDevelop a set of operating conditions that allow satis occurrenceorily separate ethanol from hexane. To do this equal volume of hexane and ethanol in a small vial were combined and injected. Inject this mixture into GC and ensure two decide peaks. Inject pure hexane to score its identity.The oven temperature was decreased from 8 0 degree C to 70 and consequently to 60 degrees C to separate the two peaks. desex ethanol standards 0.2 ml, 0.5 ml, 1.0 ml and 2.0 ml in 25 ml DI water.Concentration, 0.2 ml = 0.2/25 = 0.008 %,0.5 ml = 0.5/25 = 0.02 %1.0 ml = 1.0/25 = 0.04 %2.0 ml = 2.0/25 = 0.08 %These standards were injected into GC and a normalisation curve was prepared using the peak area information obtained.The unknown gasoline sample (Unknown Sample D Ethanol in hexane) was interpreted and 5.0 of it was transferred to a vial. 5.0 ml of water was added and mixed thoroughly in the vial. It was allowed to stand for 5 minutes.The water layer was taken using a Pasteur pipette and injected into GC.The % ethanol was determined using calibration curve data and peak area data from step 5.Observations, Calculations and ResultsInstrument GC SSTInstrument settingsInjector temperature 200 degree CDetector temperature 250 degree COven temperature 60 degree C (Earlier 80 degree C and 70 degree C)Attenuation between 4 and 16Carrier gas pressure 8-10 psiFID range 1Valve Split 1 onSolutionOven temperature (in degree C)Retention timePure Hexane600.500Hexane + Ethanol80Hexane 0.483Ethanol 0.683(Less resolved peaks)Hexane + Ethanol70Hexane 0.483Ethanol 0.750(Better resolved peaks)Hexane + Ethanol60Hexane 0.500Ethanol 0.916(well resolved peaks)SolutionPeak Area precedent 0.008 %,2186.8Standard 0.02 %3509.9Standard 0.04 %5296.3Standard 0.08 %8746.5Sample (1st Injection)Sample (2nd Injection)1982.22138.1Calculating % of ethanol in sampleEquation of line from standard curve y = 89994x + 1605.1where, y = peak area, x = concentration of ethanol in %From Observation table 3 we have,Area of sample = 1982.2 and 2138.1Putting these values in equation in place of y we get,1982.1 = 89994x + 1605.1 2138.1 = 89994x + 1605.1On solving for x we get, x = 0.00418 % and x = 0.00592 %Averaging the two values, we get x = 0.00505 %So, the % of ethanol in the given(p) Unknown Ethanol in Hexane Sample D is 0.00505 %.Expe riment 3- Qualitative and Quantitative analysis of BTEX (Benzene, Toluene, Ethylbenzene and Xylene)ProcedurePart A Qualitative AnalysisTake 1 ml each of Benzene, Toluene, Ethylbenzene and Xylene in separate vials. hightail it the individual standards and record the belongings times.Part B Quantitative analysisPrepare a series of standard of toluene and para-xylene using hexane as a solvent.Make 2,4,6,8 and 10 % solutions of each of toluene and para-xylene in 50 ml volumetric flasks.For 2 %= 1 ml each of toluene or para-xylene (separate), for 4 % = 2mlFor 6 % = 3 ml, for 8 % = 4 ml, and for 10 % = 5 ml to 50 ml with hexane.Prepare a calibration curve based on the peaks area data obtained.Analyse an unknown sample of BTEX provided and find the % of toluene and para-xylene in it using the standard curve data.Observations, Calculations and ResultsInstrument GC SSTInstrument settingsInjector temperature 200 degree CDetector temperature 250 degree COven temperature 80 degree CAttenuation between 4 and 16Carrier gas pressure 8-10 psiFID range 1SolutionRetention timeChlorobenzene3.866Ethylbenzene2.016p-xylene1.400o-xylene4.133Toluene1.500From individual injections of hexane, toluene and xylene, it was seen that that the retentiveness times for each of these were 0.500, 0.933 and 1.550 respectively.SolutionPeak AreaToluene 2 %939.8Toluene 4 %1254.0Toluene 6 %1987.6Toluene 8 %2260.2Toluene 10 %3210.0Para-xylene 2 %455.8Para-xylene 4 %985.0Para-xylene 6 %1168.1Para-xylene 8 %1791.5Para-xylene 10 %2222.9Sample Run 1Sample Run 210500 (Rt = 0.733)863 (Rt = 1.600)2966 (Rt = 0.733)181 (Rt = 1.600)From the sample analysis, we find that the two biggest peaks are seen at Rt = 0.733. This value neither corresponds to value of Rt for toluene (around 0.900) nor xylene (around 1.350). So we cannot identify or quantitate them.The other peak (although small) which is seen occurs at Rt = 1.600 is close to Rt for xylene (Rt for 10 % xylene is 1.600). So this peak would be for xylene.W e can find its concentration by making a standard curve for xylene from the data in Observation table 7.Calculating amount of xylene in sample.From the standard curve (Graph 2), we have the equation of liney = 217.04x + 22.45where, y = peak area, x = concentration of ethanol in %From Observation table 7 we have,Area of sample = 863 and 181Putting these values in equation in place of y we get,863 = 217.04x + 22.45 181 = 217.04x + 22.45On solving for x we get, x = 3.87 % and x = 0.73 %Averaging the two values, we get x = 2.30 %Therefore, the sample (Unknown B) contains 2.30 % of xylene and no toluene.Experiment 4 Determination of volatile compounds by headspace analysisProcedure grease was taken in a sealed vial and 1-2 drops each of toluene and p-xylene were added to it.Let the sample rest in the vial for about 10 minutes so that the volatile components gather in the headspace of the vial.After 10 minutes, using a syringe, suck out 0.3uL of the headspace keeping in melodic theme that the syringe doesnt touch the soil sample itself and headspace sample is taken from just the midway of the vial.Inject this to the GC. Perform duplicate injections if both components can not be seen at one go.Observations, Calculations and ResultsInstrument GC SSTInstrument settingsInjector temperature 200 degree CDetector temperature 250 degree COven temperature 80 degree CAttenuation between 4 and 16Carrier gas pressure 8-10 psiFID range 1SampleRetention timeCompound reconcileSoil Sample 11.0331.533TolueneP-XyleneSoil Sample 21.0501.483TolueneP-XyleneFrom Observation Table 7, break down experiment, we know retention times of both toluene and p-xylene. They were 0.950 and 1.550. So on comparing these Rts with the Rts obtained in these chromatograms, we can identify the peaks as toluene or xylene as done in Observation Table 8.So, using headspace analysis, Toluene and p-xylene could be identified in the soil sample.Discussion and demonstrationIn this lab, using the techniq ue of Gas Chromatography, four different experiments were performed.In Experiment 1 the ethanol content in a mouthwash was determined. This was done by using an internal standard of butanol. Then, solutions of internal standard with unknown solution and ethanol were made and injected into the GC. The areas obtained for each compound were then used to calculate the % alcohol in the sample. The amount of ethanol usher in the unknown solution of ethanol was found to be 1.00 % and the ethanol content in mouthwash was found to be 0.98%.In Experiment 2 ethanol content in gasoline mixture was calculated using a standard curve of ethanol made with pure ethanol (An unknown ethanol in hexane sample was used). The gasoline mixture was extracted with water to extract the ethanol in it for further analysis by GC. The amount of ethanol that was found to be present in this sample was 0.00505%. Firstly, we injected pure hexane and ethanol to find out their retention times and then an equal mixtur e was injected to see if the two peaks can be resolved or not. After doing this, the experiment was performed. The calculations for determining the % of ethanol were based on equation that was derived from the standard curve from ethanol standards. The value of peak area obtained in the chromatogram for the unknown sample was substituted in the equation from standard curve to find the ethanol concentration.This GC method is even used industrially to find ethanol content in gasolines, plus oxygenates like butyl ether that can contaminate drinking water.In Experiment 3 qualitative analysis of BTEX (Benzene, Toluene, Ethylbenzene and Xylene) was performed by injecting pure solutions of these compounds in GC. The retention times obtained were recorded for each.In the second part, quantitative analysis of toluene and p-xylene was done. Standard solutions of toluene and xylene were made and calibration curves were made for each. Next, the unknown sample of BTEX was injected to GC. The ret ention areas obtained were recorded and substituted in equations of standard curves to find the actual content of toluene and xylene in sample. It was found that the unknown sample had not retention that matched with the retention times of toluene which was close to 0.9550. No peaks were seen at this retention times even on duplicate runs of the sample. So it is concluded that the sample had no toluene in it. Nevertheless, a peak for xylene was seen (determined by comparing the Rt with the Rt of toluene from Experiment 3). A standard curve was made from the data obtained by running xylene standards. Now with the equation of calibration curve and the peak area of sample for xylene, the concentration of xylene present in the sample was calculated. It was found to contain 2.30 % xylene.In Experiment 4 the technique of headspace analysis was used to determine the volatile compounds in a contaminated soil sample. The soil sample was deliberately contaminated with toluene and xylene and p laced in a vial for 10 minutes. Then using a syringe, the headspace was sucked and injected to GC for performing a qualitative analysis (the retention times of BTEX from Experiment 3 were used). The peaks for both toluene and xylene could be detected by GC. This conclusion was based on the fact that the peaks had comparable retention times as toluene and xylene.To conclude, we can say that we used GC for quantitative analysis like analysis of BTEX in chemicals, food, etc. or BTEX in soil. And qualitative analysis like determination of ethanol content in gasoline, mouthwash, etc.ReferencesPage 67-73 Chromatography Laboratory Manual, shorthorn College 2012Advantages of GC http//www.sge.com/support/training/fast-gc-analysis/advantages-/-disadvantages-of-fast-gc)Industrial applications of GC(http//www.med.cmu.ac.th/dept/vascular/alcho/ question/res_out/Application%20of%20gas%20chromatography.pdf)