Download Thin Layer Chromatography PreLab and more Lab Reports Organic Chemistry in PDF only on Docsity! Report sheet Worksheet 6 Thin-Layer Chromatographic Analysis of Analgesics NAMES: ClarityD. DATE OF SUBMISSION: November 13, 2021 1. Provide the purpose of each of the following: a. TLC plate The TLC plate is used to identify the molecules on which is more polar and which is not. Since the TLC plate is coated with the silica gel. Different substances get to be pulled apart more due its polarity. b. ethyl acetate The ethyl acetate is used as a polar solvent in the mobile phase to further separate polar compounds with the non-polar compounds c. UV lamp Since the sample placed on the TLC plate is colorless and doesn’t appear in normal light, the UV lamp is used to view the spot placed in the plate d. ceric ammonium molybdate The cerium ammonium molybdate acts as a stain to the sample for easier observation of the sample when we can’t easily observe in UV light 2. Answer the following questions briefly, but concisely: a. Can you use pen as a marker when using TLC plate? No, you cannot use a pen to mark the TLC plate as it may smear on the plate and may cause some complications during the chromatography process b. Why is it necessary to allow the mobile phase to stand for at least 30 minutes inside the development chamber before placing the TLC plate? This is to allow the samples to start traveling upwards and for the sample to travel until the solvent reaches the line c. Why must the spot be applied to the TLC plate above the level of development solvent? This is to avoid the sample from dissolving in the solvent. Otherwise, the sample would touch the solvent and will dissolve rather than travel up. d. What will be the result of adding too much sample to the TLC plate? The spots will act clunky, so the polar and nonpolar molecules do not separate and thus will not travel far from the end of the plate and can cause inaccuracies in determining the distance. e. What are the advantages and disadvantages of using TLC technique? Advantages: Various samples can be tested simultaneously so TLC is time-efficient Determining the Rf value will be more accurate We don’t use too much solvents in TLC Disadvantages: The separation length of some samples is insufficient Results obtained in TLC are difficult to reproduce Only non-volatile compounds can be tested in TLC 3. Enumerate other chromatographic techniques/instruments other than thin layer chromatography. Summarize the principle behind each techniques/instrument. What information can be obtained from each techniques/instrument to identify the analyte. Column chromatography = This technique is used for the purification of biomolecules where a wash buffer is applied on a column. From this, we can understand the characteristics of different proteins.
