THF and hexane are the non polar for mobile phases Silica is the most mobile

Thf and hexane are the non polar for mobile phases

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then acetonitrile. THF and hexane are the non-polar for mobile phases. Silica is the most mobile phase while C8 (Si-O-Si-C8) is at the middle while C18 (ODS) is non-polar ( Giddings, J. C. 2017 ). Compounds in solution such as URA is the most polar. Uracil is the
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HPLC CHROMATOGRAPHY 10 molecule that does not interact with other molecules since it has no chemical affinity for the ligands. It is because Uracil is hydrophilic and the ligand is hydrophobic so they will try their best to stay away from each other. When uracil does not interact with the ligand the time it takes for the sample solvent to cross the column travelling in the space left by the stacking of round beads, it is the minimum time that it takes for any molecule to arrive to the detector. It is also called t0 = time that it takes for an unretained compound to elute. The sample solvent and uracil depend on the flow rate because they are dragged in the mobile phase so they go at the same spaced as the MP. Ketoprofen molecules take longer to elute from the column because it has to travel along the column the same way as uracil but it stops many times to interact with the ligands at the surface and in the pores of the beads ( Lenca, N., & Poole, C. F. 2017 ). The speed of Ketoprofen in the mobile phase has the same speed as uracil since when ketoprofen does not interact with the stationary phase, it is dragged by the mobile phase the same way as uracil. Ketoprofen spends the same time in the mobile phase as uracil since ketoprofen elution time (the time it takes for the molecule to reach the detector retention time) comprises: The time it spends in the mobile phase which is the same as the time that uracil spends in the mobile phase (t0) Plus the time it spends interacting with the stationary phase (Ligands) because it has affinity for it. Through the time spent in the mobile phase that is same as uracil is how we can access the time Ketoprofen spends in the stationary phase if retention time (Tr) are T0 are known. Accessing T0 with the elution time of URA and Tr with the Tr of the peaks in the chromatogram can be deduce the time that the molecules spend interacting with the stationary phase Tr for instance if T0 = 2 minutes and Tr of Ketoprofen = 10 minutes. Ketoprofen will
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HPLC CHROMATOGRAPHY 11 spend 2 minutes in the total in the mobile phase and elutes for 10 minutes in the retenation time. Retention Factor of a molecule (K) is the ratio of the time the molecule spends in the stationary phase to the time it spends in the mobile phase. The equation for retention factor K is K = (Tr – T0)/ T0 = (10 – 2)/2 = 4 Evaluation of the chromatographic and graphical results Before the practices the hypothesis on how temperature affects the response will remain the same when it comes to AUC. Observations and Results i. The AUC of pk7 almost maintain in 4990 in 40 and 60 degree, which is just a little bit higher than its in 25 degree (4661).
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