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Amino Acid Separation & Analysis. Lab #2. Materials & Supplies. Erlenmeyer flask w/Solvent & black stopper Toothpicks x2 Chromatography strips (cut to 20cm) x2 Ruler Pencil Latex gloves (one pair for one student) Amino acid vial (one per pair of students). Procedure/Important Reminders.
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Materials & Supplies • Erlenmeyer flask w/Solvent & black stopper • Toothpicks x2 • Chromatography strips (cut to 20cm) x2 • Ruler • Pencil • Latex gloves (one pair for one student) • Amino acid vial (one per pair of students)
Procedure/Important Reminders • Never touch the Chromatography strip with fingers or hands. Oils from skin will affect your results • Mix vigorously the vials of amino acid before applying on the strip. • Be sure the 3 letter symbol of the amino acid and period is clearly written at the bottom of strip. • Use only pencil. No Pens !!! • Do not let sample dot get submersed. • Do not let the strips touch the sides of the flask or touch each other if more than one strip in a flask. • Do several applications with the toothpick to insure you have an adequate amount of amino acid on the strip. • Be sure that you staple your amino acid to the drying strip. • Have your partner hold the amino acid vial as you dip the toothpick into it. Don’t spill or let the tube roll off the lab table.
Day 2- Amino Acid Lab • Follow same procedure from day one with the unknown sample. • Find your strip and outline in pencil the spot that • precipitated. Locate the center point of the spot and pencil in a dot. • Measure the distance the amino acid moved from original line (cm) • Measure the distance the solvent traveled (cm) • Calculate your Rf value. • Cut the strip in half so each person has a side and indicate these two measure point on the strip-you’ll attach these to you results page. • Enter you data on the class table (my computer) • Make a data table for yourself with the values that are recorded. • Think about possible relationships between the amino acid and Rf values. (ie. Molecular mass vs. Rf value)
Homework: • Continue to research other methods for separating amino aids what Rf values should we expect to see? • Complete the amino acid table • Graph possible relationships between amino acid and Rf, molecular mass, etc. • Do Conclusion Quest. #1-4 • Study Guide: SK #1 & 2
Lab #2-Report Guidelines-Due 9/30 • Title: Must reflect what this lab is about. (be creative) • Introduction & Background-What is the significance of this lab? What are some other ways to do this lab? Which method are we choosing? Why this method? • What are the independent, dependent, and control variables • Hypothesis-Expected outcome (Rf values, dist moved, Molecular mass, chemical properties) • Methods & Procedures • Results-need table, strip result sheet, graphs, your pick of the unknowns. • Analysis: How did you come to this result? How close were you to choosing the actual unknowns? • Conclusion: Does your data support your hypothesis? What are the sources of error? How could you correct these problems? • References- Websites &, articles, and other resources ***Note: you may use a word processing program to write the report.
Analysis & Conclusions • Results of Unknown: • Distance of 1st spot: • Distance of 2nd spot: • Distance Solvent: • Rf values: 1st amino acid: 2nd amino acid:
