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

1. How does chromatography separate the components of leave samples? 2. Can you use chromatography to purify a mixture? why? 3. What is Rf value and its significance in chromatography?

How else can chromatography be used?   None of these answers are correct.   To wash (or remove) unwanted solvents from a mixture.   To identify or exclude components in a mixture.   To generate IUPAC names for hydrocarbons.

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

Identify the detectors in gas chromatography that can be used for the detection of each type of analyte. More than one detector may be appropriate for a given analyte, and a given detector may be appropriate for more than one type of analyte. compounds ionized by UV radiation sulfur or nitrogen containing compounds halogenated compounds flame ionization Answer Bank mass spectrometer nitrogen and phosphorous containing compounds thermal conductivity electrolytic conductivity hydrocarbons electron capture thermionic photoionization

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

Pre-Lab Questions Experiment 12 Food Chromatography: The Distance Our Food Travels Name: Section: Instructor: Date: Imagine you have a solution that is comprised solely of component A. You have another solution that is comprised solely of component B, and yet a third solution that is comprised solely of component C. Component A's retention factor is about 0.84, Component B's retention factor is about 0.21, and Component C's retention factor is 0.55 in the same solvent system. You then have a fourth solution that is composed of components A and C. 145 You spot each solution on a piece of chromatography paper and allow the solutions to separate. Sketch what you think your paper would look like below.

2. Consider the following example GC Chromatogram from a publication about aggression among Mediterranean Acrobat Ants (C. scutellaris). This particular sample was generated by rinsing hydrocarbons from ant exoskeletons. From the chromatogram, what is the minimum number of unique compunds present in the sample? What data led you to that conclusion? (Don't overthink it) 2 8000000 7000000 6000000 5000000 4000000 3000000 2000000 1000000 Counts (Abundance) 5 19 6 7 0 23.00 24.00 10 | 11 13 17 20 14 15 16 12 teel | 22 19 21 ли 25.00 26.00 27.00 Time "Example of a Gas chromatography-Mass spectrography (GS-MS) chromatogram of hydrocarbon molecules in C. scutellaris" by Filippo Frizzi, et.al, in PLoS One is licensed under CC BY 4.0

Using the data provided please help me answer this question.  Determine the concentration of the iron(Ill) salicylate in the unknown directly from to graph and from the best fit trend-line (least squares analysis) of the graph that yielded a straight line.

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?

The uses of thin layer chromatography are: 1) To identify unknown compounds 2) Determine purity of products 3) Analyze reaction mixtures 4) To waste time in lab 5) Determine the melting point of the product U 6) Put an astronaut on the moon.

Separate a mixture of Vitamin D and Vitamin B2 (riboflavin) by paper chromatography. The stationary phase is methanol (CH;OH) and the mobile phase is pentane (C;H12). Place the vitamins in order of elution. Explain why using IMF. (Circle polar sites on each molecule and label all 4 molecules as polar or non-polar.) Vitamin Ba 0: H3C NH H3C CH3 CH3 CH3 H3C He H3C HO CH2 Vitamin D He CH2OH HO

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