Loading...

Messages

Proposals

Stuck in your homework and missing deadline? Get urgent help in $10/Page with 24 hours deadline

Get Urgent Writing Help In Your Essays, Assignments, Homeworks, Dissertation, Thesis Or Coursework & Achieve A+ Grades.

Privacy Guaranteed - 100% Plagiarism Free Writing - Free Turnitin Report - Professional And Experienced Writers - 24/7 Online Support

Biology

10/09/2020 Client: bingyanj Deadline: 7 Days

Abstract


Determination of caffeine content of tea and instant coffee brands found in the Kenyan market 


H. N. Wanyika*, E. G. Gatebe, L. M. Gitu, E. K. Ngumba and C. W. Maritim 


Department of Chemistry, Jomo Kenyatta University of Agriculture and Technology, P. O. Box 62 000 – 00200, Nairobi, Kenya. Accepted 12 April, 2010




 Caffeine (1, 3, 5-trimethylxanthine), a mild addicting drug though used for medicinal purposes is the active ingredient that makes tea and coffee valuable to humans. In this study, the levels of caffeine in certain coffee (nescafe, africafe, dormans) and tea (chai mara moja, kericho gold, sasini, finlays premium) brands found in the Kenyan market were determined using high performance liquid chromatography (hplc) and UV/ Vis spectrophotometric methods. The levels of caffeine in all the tea and coffee brands were found to be within the documented range. The order of caffeine concentration in tea samples was found as follows: chai mara moja > finlays premium > kericho gold > sasini. In coffee it was found that the caffeine content of africafe > nescafe > dormans. Generally, higher concentration of caffeine in all the samples were realized with the UV/ Vis spectrophotometric method compared to hplc method indicating that acidified water was a better caffeine extractor than pure water.




Based on the Absorbance Spectrum in Figure 1, what is the maximum absorbance wavelength for caffeine?




Construct a Standard Reference Graph in Excel for the Caffeine using the following data:




 




Determine the concentration of caffeine from the Standard Reference Graph for the following beverages given their absorbance values when tested with a spectrophotometer.




Absorbance


Chai Mara Moja Tea .26


Nescafe instant coffee .13


Finlay Tea .18


Africafe coffee .12




Helpful website to construct and understand the standard reference graph:


https://www.nku.edu/~whitsonma/Bio150LSite/Lab%202%20Water/SpectrophotometryII.html




Helpful video on how to Excel to construct the standard reference graph.


https://www.youtube.com/watch?v=KeTFzJUG_rA 




Questions: 




1. Look at the standard reference graph.  What is the independent variable and dependant variable?




 2. Explain how the relationship between  absorbance and concentration based on Beer’s Law.




3. If the wavelength is changed, what will happen to the absorbance value? 




4. What would be another real world application for spectrophotometry?



Homework is Completed By:

Writer Writer Name Amount Client Comments & Rating
Instant Homework Helper

ONLINE

Instant Homework Helper

$36

She helped me in last minute in a very reasonable price. She is a lifesaver, I got A+ grade in my homework, I will surely hire her again for my next assignments, Thumbs Up!

Order & Get This Solution Within 3 Hours in $25/Page

Custom Original Solution And Get A+ Grades

  • 100% Plagiarism Free
  • Proper APA/MLA/Harvard Referencing
  • Delivery in 3 Hours After Placing Order
  • Free Turnitin Report
  • Unlimited Revisions
  • Privacy Guaranteed

Order & Get This Solution Within 6 Hours in $20/Page

Custom Original Solution And Get A+ Grades

  • 100% Plagiarism Free
  • Proper APA/MLA/Harvard Referencing
  • Delivery in 6 Hours After Placing Order
  • Free Turnitin Report
  • Unlimited Revisions
  • Privacy Guaranteed

Order & Get This Solution Within 12 Hours in $15/Page

Custom Original Solution And Get A+ Grades

  • 100% Plagiarism Free
  • Proper APA/MLA/Harvard Referencing
  • Delivery in 12 Hours After Placing Order
  • Free Turnitin Report
  • Unlimited Revisions
  • Privacy Guaranteed

6 writers have sent their proposals to do this homework:

Top Academic Guru
Academic Master
Buy Coursework Help
Smart Homework Helper
Professional Accountant
Writer Writer Name Offer Chat
Top Academic Guru

ONLINE

Top Academic Guru

This project is my strength and I can fulfill your requirements properly within your given deadline. I always give plagiarism-free work to my clients at very competitive prices.

$135 Chat With Writer
Academic Master

ONLINE

Academic Master

I have super grip on essays, case studies, reports and discussion posts. I am working on this forum from last 6 years with full amount of satisfaction of my clients.

$140 Chat With Writer
Buy Coursework Help

ONLINE

Buy Coursework Help

I can help you with your project. I will make sure to provide you exceptional quality work within the required timeframe. Please message me so we can discuss the further details over chat.

$135 Chat With Writer
Smart Homework Helper

ONLINE

Smart Homework Helper

Greetings! I am the professional electrical, telecom engineer, rich experience in QPSK, OFDM, FFT, such signal processing concetps with matlab, I can satisfy you definitely. more in chat.thanks.

$155 Chat With Writer
Professional Accountant

ONLINE

Professional Accountant

Hi! It is good to see your project and being a reputed & highest rated freelance writer on this website, you can be assured of quality work! I am here to provide you with completely non-plagiarised work

$155 Chat With Writer

Let our expert academic writers to help you in achieving a+ grades in your homework, assignment, quiz or exam.

Similar Homework Questions

Neda 1604 iec 6f22 - University of leeds vle - Express your answer as a chemical formula - Security Threats & Vulnerabilities - Assignment 3 cultural activity report - Macrowikinomics new solutions for a connected planet pdf - Cia exam pass rate by part - Article 10 application form - Grant v australian knitting mills 1935 - Clinical labs modbury triangle - Work - Validity reliability and accuracy - A clockwork orange symbols - High tibial osteotomy protocol - Measurement of three phase power with the 2 wattmeter method - Respond to the following: - George cloutier net worth - 4 question to answer from Principle of business management - Discussion Along with PA 2 Paper - Peyton approved trial balance 2018 - Application letter for civil engineering job - Procedures before accepting audit engagement - Comparison and contrast examples sentences - Constructs and operational definitions - Costco employee turnover rate 2012 - Features of international financial market - How to type spanish letters in word - Terre mere active coconut charcoal clarifying cleanser review - Sustainbility Essay - Alex steiner the book thief - Offset air cleaner stud o reilly - Deep purple members today - Writing - Psychology Discussion SUPER EASY - Human resource - Why does the market leader use comparative messages - Diabetic ketoacidosis concept map - Project Assignment: - Discusstion 500 words - Karma kismet new delhi delhi - What is mco in healthcare - What phylum is red algae in - Discussion - Advance business logistics and Public policy Discussion - Song for the dead - Biovail corporation case study answers - Electricity and Magnetism - ) Discuss the extent to which the IASB conceptual framework satisfies the above definition of fairness in Leonard’s comment above. (40 Marks) b) Discuss the extent to which the above criticisms could be justified by reference to specific International Financial Reporting Standards. - Strategic plan part ii swott analysis - Self evaluation form guidance - Project Proposal - Controlling and Leading - Convert hz to kva - Conflict Managment Paper 1 - Pdf expert copy image - Aldi water filter pitcher - ERM Research Topics - Easa part 145 regulations - NEED IN 8 HOURS or LESS (NO EXCEPTION) - Australia ania walwicz poem - Homework4 - Maths methods unit 1 and 2 practice sacs - Leadership Clinicals discussion - Kings cross dundee audiology - Now o'er the one half world meaning - Scope of strategic financial management - Scott barber performance testing - Cableduct 700 series prices - Paper - Cmgtmg - Peasants and artisans in japan - Cloud Computing - Assignment 1 (Only for kim woods) Course: Information Systems - Pecha kucha google slides template - Persuasive speech about no homework policy - Inventory management assessment - Nursing theory and conceptual model - St jude international gala for hope - Use the data in gpa for this exercise - Assignment 5 professional cover letter - 3 page research paper on us prisons - Bristol dental hospital referrals - Annotated Bibliography - Cell structure and function experiment - Busbar current carrying capacity calculator - Accounting 201 Monopoly - Matric exemption application form - Ucl foreign language requirement - 2020 english paper 2 - Legal costs negotiators salford - Instant paper clip office supply company - Cet cette ce ces - Reflection memo - Mtv global expansion - Chc50612 diploma of community services - Food - P10 1a accounting answers - Common module human experiences - Listen to the yell of leopold's ghost - Final will and testament template - Nutrition