Spring 2021 CHE 3010 Palmer This work by Alycia Palmer is licensed under CC BY 4.0 1 Lab Practical : analysis of dye s in a spor ts beverage Spectrophotometric determination of FD&C dye concentration in a sports drink Objective Students will determine the concentration of FD&C dyes in sports drinks in order to replicate the manufacturerâ€™s formula. After replicating the formula, students will compare their color to that of the sports drinks available to identify their unknown. Logistics The duration is three weeks and students will work individually. Students should aim to a ccomplish the following during each week. Week 1: Obtain the unknown and its absorbance spectrum. Create calibration standards. Week 2: Measure standards and complete the spreadsheet. Week 3: Determine the concentration of each dye and mix a sample to iden tify your unknown. Introduction Commercial manufacturers are required to label the contents of food items, including which dyes are used. However, the amounts of the dyes are usually kept secret. All of the beverages in this lab contain two of the follow ing dyes. FD&C Color No. Chemical Structure Molar Mass (g/mol) Red 40 (Allura Red) 496.42 Yellow 5 (Tartrazine) 534.3 Yellow 6 (Sunset Yellow) 452.4 Experiment 5
Spring 2021 CHE 3010 Palmer This work by Alycia Palmer is licensed under CC BY 4.0 2 B lue 1 (E rioglaucine ) 792.85 Procedure The purpose of the lab practical is for you to determine your own procedure to quantify the amount of two dyes in an unknown beverage . Use what you have learned in previous labs about Beerâ€™s law and calibration curves as well as what you learned in lecture about determining concentration when there is spectral overlap. You may use the spreadsheet to help guide you in your data collection. Be sure to detail your steps in your lab notebook. Full lab report (15% of final lab grade) Consult the rubric on Canvas for the point itemization of each section. Abstract In less than 250 words, tell the purpose of the lab, your unknown code , and your main conclusion. Do not discuss the chemistry of your results or any errors here. Introduction In less than 250 words, give informa tion about the dyes in your beverage and the techniques used in the experiment. Use in text citations where references are used. Methods Describe your procedure in sufficient detail so that another peer could duplicate your work. This s ection must contain complete sentences and be in paragraph form (no bullet points). Describe all reagents and instruments used. Results The key to a good results section is to spend time making great figures and tables. The figures and tables will be used to tell your story. You should use your own judgement to determine which figures and tables to include. Discussion This section should be similar to a conclusion. State the purpose, summarize your main results, and discuss your error. Make sure to cover the following points. Tell your unknown code and the concentration determined for each dye. When you mixed a sample based off of your calculations, were you able to identify the beverage? What empirical evidence do you have that the two colors are the â€œsam eâ€? References Any references should be cited at the end of your conclusion using ACS specifications.