Question

Please answer it ALL completely and write clearly, thank you.

                           ( 10 marks )

                         ( 10 marks, PLS answer complete )

5. (a) The following data was obtained from a gas chromatographic analysis of fatty acids Data berikut telah diperolehi daripada analisis kromatografi gas asid lemak: Column Supelco SP-2300, 25 m, 0.29 mm i.d Condition T 50 °C; Tf-150°C; Ramping rate -5°min Peak number tr (min) Ion Count 1.95 2.43 2.59 2.72 10.33 12.40 13.38 16.42 22359.5 1348876.5 67553.0 191120.0 972372.5 70224.0 43338.5 66851.0 (i)Was a normal column or a capillary column used in the analysis? (i) Was the analysis done using isothermal or temperature programmed condition? ii) How can you tell that the detector used was a mass spectrometer? iv) Peak number 7 was suspected to be a bromine containing compound. How can that be conclusively detemined using the same technique? Suggest a way(s) to improve the analysis specifically on how to better resolve peaks numbers 1-4. (v) Ethylene sometimes can be found as an impurity in ethane tanks. The presence of ethylene in ethane tanks can be detected using infrared (IR) spectroscopy by monitoring the absorption at 2080 cm1. In an analysis, a series of gas standards containing ethylene was measured using IR spectroscopy. The absorption intensity at 2080 cm-1 was recorded as follows: % ethylene in gas standard Absorption 0.5% 0.125 0.255 0.380 0.502 0.620 0.745 1% 1.5902% 2.5903% An ethane gas tank suspected to be contaminated with ethylene was found to give an absorption reading of 0.450 at 2080 cm-1. Calculate the percentage of ethylene found in the gas tank.

Answer 1

JA 5ai)プhe, Capillary Column ued in analysis, i) done an temmperatucprog Be caun ng-tak. _jn dekcoyuocd in an iv) ne bromine giun tel Vadsie 02-а 0.502