Homework Help is Here – Start Your Trial Now!
Science
Chemistry
Table. Absorbance data for iron standards and flour samples Fe Conc. (mg/L) Corrected Sample Absorbance Absorbance Reagent Blank Standard 1 0.01 2.0 0.22 0.21 Standard 2 4.0 0.40 0.39 Standard 3 6.0 0.63 0.62 Standard 4 8.0 0.79 0.78 Standard 5 Flour Sample 1 Flour Sample 2 Flour Sample 3 10.0 1.03 1.02 0.28 0.27. 0.29 0.28 0.26 0.25

Table. Absorbance data for iron standards and flour samples Fe Conc. (mg/L) Corrected Sample Absorbance Absorbance Reagent Blank Standard 1 0.01 2.0 0.22 0.21 Standard 2 4.0 0.40 0.39 Standard 3 6.0 0.63 0.62 Standard 4 8.0 0.79 0.78 Standard 5 Flour Sample 1 Flour Sample 2 Flour Sample 3 10.0 1.03 1.02 0.28 0.27. 0.29 0.28 0.26 0.25

Chemistry
Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
See similar textbooks
icon
Related questions
Question
100%
(d) Heat on a Kjeldahl burner in a hood until white SO3 fumes form. (e) Cool, add 25 ml of deionized water, and filter quan- titatively into a 100-ml volumetric flask. Dilute to volume. (f) Prepare iron standards with concentrations of 2, 4, 6, 8, and 10 mg/1. (g) Install an iron hollow cathode lamp in your atomic absorption spectrometer and turn on the instrument and adjust it according to instructions in the operating manual. (h) Run your standards and each of your ashed samples and record the absorbances. Calculate the iron concentration in each of your replicates, express as mng Fe/lb flour. Table. Absorbance data for iron standards and flour samples Fe Conc. Corrected Sample (mg/L) Absorbance Absorbance Reagent Blank Standard 1 0.01 2.0 0.22 0.21 Standard 2 4.0 0.40 0.39 Standard 3 6.0 0.63 0.62 Standard 4 8.0 0.79 0.78 Standard 5 Flour Sample 1 Flour Sample 2 Flour Sample 3 10.0 1.03 1.02 ? 0.28 0.27 0.28 0.25 0.29 ? 0.26
Transcribed Image Text:(d) Heat on a Kjeldahl burner in a hood until white SO3 fumes form. (e) Cool, add 25 ml of deionized water, and filter quan- titatively into a 100-ml volumetric flask. Dilute to volume. (f) Prepare iron standards with concentrations of 2, 4, 6, 8, and 10 mg/1. (g) Install an iron hollow cathode lamp in your atomic absorption spectrometer and turn on the instrument and adjust it according to instructions in the operating manual. (h) Run your standards and each of your ashed samples and record the absorbances. Calculate the iron concentration in each of your replicates, express as mng Fe/lb flour. Table. Absorbance data for iron standards and flour samples Fe Conc. Corrected Sample (mg/L) Absorbance Absorbance Reagent Blank Standard 1 0.01 2.0 0.22 0.21 Standard 2 4.0 0.40 0.39 Standard 3 6.0 0.63 0.62 Standard 4 8.0 0.79 0.78 Standard 5 Flour Sample 1 Flour Sample 2 Flour Sample 3 10.0 1.03 1.02 ? 0.28 0.27 0.28 0.25 0.29 ? 0.26
1. Your company manufactures and markets an enriched all-purpose flour product. You purchase a premix con- taining elemental iron powder, riboflavin, niacin, thi- amin, and folate which you mix with your flour during milling. You specified to the supplier that the premix be formulated so that when added to flour at a spec- ified rate, the concentration of added iron is 20mg/lb flour. However, you have reason to believe that the iron concentration in the premix is too low so you decide to analyze your enriched flour using your new atomic absorption spectrometer. Current FDA guidelines for enriched flour specify that the iron concentration should be 20 mg/lb: http://www.accessdata.fda.gov/scripts/ cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=137.165 (accessed 6/18/2009). You follow the following protocol to deter- mine the iron concentration. (a) Weigh out 10.00 g of flour, in triplicate (each replicate should be analyzed separately). (b) Transfer the flour to an 800-ml Kjeldahl flask. (c) Add 20ml of deionized water, 5ml of concentrated H,SO4, and 25 ml of concentrated HNO3
Transcribed Image Text:1. Your company manufactures and markets an enriched all-purpose flour product. You purchase a premix con- taining elemental iron powder, riboflavin, niacin, thi- amin, and folate which you mix with your flour during milling. You specified to the supplier that the premix be formulated so that when added to flour at a spec- ified rate, the concentration of added iron is 20mg/lb flour. However, you have reason to believe that the iron concentration in the premix is too low so you decide to analyze your enriched flour using your new atomic absorption spectrometer. Current FDA guidelines for enriched flour specify that the iron concentration should be 20 mg/lb: http://www.accessdata.fda.gov/scripts/ cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=137.165 (accessed 6/18/2009). You follow the following protocol to deter- mine the iron concentration. (a) Weigh out 10.00 g of flour, in triplicate (each replicate should be analyzed separately). (b) Transfer the flour to an 800-ml Kjeldahl flask. (c) Add 20ml of deionized water, 5ml of concentrated H,SO4, and 25 ml of concentrated HNO3
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 5 steps with 1 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Spectroanalytical Methods
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Chemistry
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY
SEE MORE TEXTBOOKS