Lab 4_TLC Report

Table of chemicals and reagents with their physicochemical properties (name, molecular formula, molecular weight, pKa, melting point, boiling point, etc.) Write a short outline or a flow diagram of the procedure List and safety issues Read and understand the MSDS information for each chemical used in this practical Experimental procedure Please do not scratch the clear sides of the UV cuvettes as this will invalidate your results. Part 1: Preparation of a calibration curve A calibration curve should be constructed using at least five concentrations of the pure paracetamol standard supplied in the range 3-15 ug/mL as follows: Weigh about 150 mg of paracetamol accurately and transfer to a 200 mL volumetric flask. Add 50 mL of o.1 M NaOH and dilute to about 100 mL with deionised water (DI). Shake and make up to volume with DI water. Dilute 10 mL of the resulting solution to 100 mL (volumetric flask) with DI water (= stock solution). Prepare standard solutions containing 3, 6, 9, 12 and 15…

According to the following TLC, do you see any evidence on the TLC that product was lost? a Yes, TLC shows the product is also in the mother liquor (filtrate). b Yes, TLC shows product in the crude sample. c No, TLC is not quantitative. d No, there is no evidence on the TLC that the product was lost

Three students did a chromatography experiment, where Rf = distance of solute / distance of solvent. What could be the possible errors why student 3 had results that are quite far from that of students A and B?

Use the simulation lab to obtain the distance for the solvent front and the distance for each spot and then calculate the Rf 35ig figs acetaminoph Unknown Unknown Sample caffeine ibuprofen aspirin en Mixture #1 Mixture #2 13.0 cm13.0 cm 13. O cm 13.0 cm 13.0cm Distance to 130 cm solvent front 1.77cm 1.89cm 11.1 12.6 cm 1.78cm la.6 cm 11.0 cm 6.27cm Distance Spot(s) traveled 5.58cm Calculated R:(s) Components of Unknowns D. Additional Exercises 1. Which of the substances tested is most polar? What parts of the structure of this substance is polar? 2. Which of the substance tested is most non-polar? What parts of the structure of this substance in non-polar?

Column Chromatography Alumina Chromatography Mixture 9:1 Hexanes:Ether 8:2 Hexanes:Ether 1:1 Hexanes:Acetone Amount Used 3.962 g 0.143 g 9.50 mL 9.50 mL 11.00 mL Additional Observations (Color, etc.) BIU X₂ X² → BI IU X₂ X² → BI IU X₂ X² → BI IU X₂ X² → BIU X₂ X² →

Given the following chromatogra What molecules in the mixture were separated successfully in Chromatogram A? In Chromatogram B? From the given data, what are the differences between the two chromatograms?

Color BEFORE adding Color AFTER adding Intensity of color AFTER adding FeCl3 Test Tube # FeCl3 FeCl3 #1 (salicylic acid) clear lilac 100% #2 (commercial aspirin A) clear slightly pink 50% #3 (commercial aspirin B) clear lilac 95% #4 (aspirin from your clear pink 20% synthesis above) #5 (control) clear clear 0% Based on this data and the melting point of Aspirin, how pure is the synthesized product?

Please correct answer and don't use hand rating

how to get uncertainty?

Table #2 Worktable for BCA Assay Standard Water (μl) Tube # 1 2 3 4 5 6 7 8 9 0 125 325 175 325 325 325 400 400 BSA source (μl) 300 stock 375 stock 325 stock 175 of tube #2 325 of tube #3 325 of tube #5 325 of tube #6 100 of tube #7 0 Protein (ug) Add the volumes listed in Table 2 to each tube. Add the water first and then the appropriate standard. Pipette each of the protein samples directly into the water, do not dribble on the side of the test tubes. The standard is at a concentration of 2 mg/ml and contains bovine serum albumin (BSA). Calculate the amount of BSA protein added to each of the tubes and write this in Table 2 (Protein (ug)).

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.

Question 3 (b) Given the chromatogram shown below, answer the following questions: (b) Calculate the adjusted retention time for compound/peak 3 (in minutes). 3. 10 0. 5 8. 10 Time (min) HO OH Benzoic acid Phenol Toluene Benzene Detector Signal (mAU) 20

Answer number 8

10:36 1 ull ? Search Expert Q&A Done Sample G.C. : Simple Distillation Fraction 3 1500- 1000- 500- Time (min) AM Simple- F3 Sample GC of products obtained from Simple distillation of solution that is 40% ethyl acetate and 60% propyl acetate. calculate the following for each sample gas chromatograph. a) retention time for each peak (label peaks) b) area of each peak c) %composition

1. The concentration of NaOH from the best three of your trials. 2. The average concentration of 3 of your trials (only use 3 trials) 3. The standard deviation of your 3 trials [If you have a calculator with stats on it, you can use that/bring it to class, but for the lab report you will have to write out your calculations.] 4. Your PPT.

QUESTION 5 In a chromatographic separation using a polar stationary phase and a mobile phase composed of 60% hexane and 40% ethyl acetate, two compounds, benzene (peak A) and toluene (peak B), are eluted. The width of peak A at its base is 1.2 min, the width of peak B at its base is 1.3 min, and the retention time of peak A is 5.2 min and peak B is 3.5 min. What is the resolution (Rs) between these two peaks and is it acceptable? R = 1.36. It is not an acceptable resolution. R = 0.74. It is an acceptable resolution. R = 1.36. It is an acceptable resolution. R = 0.74. It is not an acceptable resolution.

In the Thermo Fisher application note about wine analysis (Lesson 3), the following chromatogram was collected of nine components of wine. If peak 3 has a retention time of 3.15 minutes and a peak width of 0.070 minutes, and peak 4 has a retention time of 3.24 minutes and a peak width of 0.075 minutes, what is the resolution factor between the two peaks? [Hint: it will help to review Lesson 2 for this question.] MAU 300 200 T 34 5 100- 1 2 CO 6 7 8 9 0 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.2 Minutes 3.22 0.62 1.04 O 1.24

2 how do you find the answer and what is the answer for each component using the volume of first table?

In the Thermo Fisher application note about wine analysis (Lesson 3), the following chromatogram was collected of nine components of wine. If peak 3 has a retention time of 3.15 minutes and a peak width of 0.070 minutes, and peak 4 has a retention time of 3.24 minutes and a peak width of 0.075 minutes, what is the resolution factor between the two peaks? [Hint: it will help to review Lesson 2 for this question.] mAU 300 200 100 0 3.22 0.62 1.04 1.24 2.4 2.6 2.8 LO 34 12 ww 3.0 5 3.2 3.4 3.6 3.8 4.0 Minutes 7 8 9 4.2 4.4 4.6 4.8 5.0 5.2