FLR 2 (1)

Question:  Using a sample of aspirin for HPLC analysis. If the aspirin was contaminated (wet) with trace amounts of a solvent such as ethyl acetate, hexane, or water, would this contaminant be detected and appear as a peak in the HPLC chromatogram? Briefly explain based on the type of detector used in HPLC analysis and what type of compounds can be detected. My Answer: The HPLC analysis detects chromophores, compounds with multiple double bonds. Since water, ethyl acetate, and hexane all lack multiple pi bonds this will not be detected in the HPLC.  -Question for you, is this complete (and correct), and should I include anything about UV detection? Is UV detection used in HPLC? I thought it was only used on TLC to show compunds that arent visable.

PART ONE: Preparation of FECNS* Solution Prepare the two solutions in table 1 by accurately measuring the required volumes of distilled water and CNS into two labeled test tubes. The absorbance of the solutions must be measured soon after adding the Fe" solution from a buret. TABLE 1 Fe 5 ml 5S mL Solution Distilled Water CNS 2 mL Total Volume 3 ml 2 ml 10 ml 3 mL 10 ml In this part of the experiment you are to explore what the above quote means. As a PRELIMINARY Exercise, formulate a hypothesis as to what would happen under each of the following circumstances: 1. 1ml of 0.0020 M CNS' solution is added to the unused portion of solution 1 in the test tube 2. One drop of 0.20 M CNS solution is added to the unused portion of solution 2 in the test tube.

How does ammonia, dimethylglyoxime (DMG), and 8-hydroxyquinoline (8HQ) interact with your cations, leading to the evolution of colored species?   Context: Paper chromatography experiment (separation of inorganic cations) with a 9:1 acetone/ HCl solvent

Use a suitable model to explain how separation and identification of a mixture of organic compounds can be achieved with a thin layer chromatographic (TLC) technique.

Gas chromatography requires a sample size. O Much, much less than a gram A gram or less 1 to 10 grams 10 to 100 grams Gas chromatography does not have a restriction on its sample size QUESTION 11 Which of the following would not have a characteristic functional group absorption in an IR spectrum? butanal benzoic acid O dimethyl ether O propanone O 1-pentanol QUESTION 12 All of the following except for is a required step in ion-exchange chromatography. The packed column is equilibrated with a buffer. O Determination of the distance traveled by the analyte. O The column is washed with additional buffer to remove unbound components. O The elution of the bound analyte. O The sample is loaded onto the column.

use the following chromatogram and table as your data.       What is the %composition of the Vitamin A peak in the sample?     78.43%        77.73%     7.867%       72.74%

A student performed a chromatography experiment to determine the Rf value of an unknown amino acid. The distances traveled by the amino acid and the solvent line were 3.0 cm and 8.5 cm, respectively. What is the Rf value for this amino acid? 0.3 cm O 0.35 1.8 5.5 0.85 cm 0.65 O 2.8

19. What is thin layer chromatography (TLC) LEAST useful for from the list below? A) To determine if crystallization or distillation may be more effective for a separation B) To determine the number of components in a mixture C) To determine the appropriate solvent for column- chromatographic separation D) To monitor the progress of an organic synthesis reaction 14. The solubility of salicylic acid in water is 7.8g/100ml at 100°C and 0.25g/100ml at 25°. Estimate how much water is needed to recrystallize a 19g sample of salicylic acid? A) 150ml B) 250ml C) 300ml D) 400ml

4) If the classification of the chromatography run is a reverse-phase chromatography, discuss the relative polarities of caffeine, aspartame and benzoate.

3. Correlate the structures of the standard food dyes to their relative position in the paper chromatogram. Refer to the structures shown below. *Na O H3C- OISI *Na HO CH3 Allura Red AC (pigment in red dye) N Hora O Na* O Na* O Nat O Na+ 0=8=0 HO 0=S=0 -O Na+ O Na+ Tartrazine (pigment in yellow dye) Brilliant Blue FCF (pigment in blue dye) 4. What are the identities of the unknowns in paper chromatography of food dyes? How did you arrive at this conclusion?

Question: Can thin-layer chromatography (TLC) be used to differentiate between two closely related compounds with similar structures?

Question attached

The surface of the silica gel has a structure that looks like this diagram below. Suppose you used a plate coated with silica gel, with propanone, CH3COCH3, as the solvent for thin-layer chromatography. Sno Suppose also that the mixture you were trying to identify contained • benzaldehyde •benzanilide • phenol 1) rank the Rf Value from large to small 2) name the IMF between each compound and the silica gel OH OH main body of silica structure

Please don't provide handwriting solution

Organic Chemistry, column questions

Pre-Lab Questions 1. Define a protein, and describe one important function of proteins in the human body. 2. The following data were obtained from a Bradford assay to determine the protein content in a sample: Protein content (ug) Absorbance value 0 0.000 2 0.022 5 0.065 10 0.106 20 0.178 30 0.299 40 0.380 50 0.472 unknown 0.150 Use Excel, another program, or graph paper to produce a calibration curve based on the data. Use linear regression (or best fit line) to obtain the slope of the line. Determine the unknown protein content for a sample that shows an absorbance reading of b. С. 0.150.

Given the following chromatogram of opiates found in urine, determine the separation resolution between morphine and fentanyl, and decide if the two peaks are resolved. Intensity (AU) 2.5 2.0 1.5 1.0 0.5 (TTTTTTT 1. Hydrocodone 2. Codeine 3. Oxycodone 4. Hydromorphone Morphine 6 Fentanyl 5. 1 ili 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 Time (min) ليد O 2.0; not resolved 2.0; resolved O 1.0; not resolved O 1.0; resolved