Principles of Instrumental Analysis
7th Edition
ISBN: 9781305577213
Author: Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Question
Chapter 10, Problem 10.1QAP
Interpretation Introduction
Interpretation:
An internal standard and its uses needs to be explained.
Concept introduction:
Use of an internal standard before actual sample analysis is an established method in analytical tests and is one important step towards eliminating/reducing the sources of errors and ensuring the accuracy and precision of the results.
Expert Solution & Answer
Answer to Problem 10.1QAP
An internal standard is a chemical substance, added to the sample, blank or calibration standards to identify and account for uncontrollable variables. The uncontrollable variables are expected to affect the internal standard and the analyte to a similar extent.
Explanation of Solution
Before actual analytical analysis of a substance, a blank and/or a calibration standard is run. This consists of a chemical substance of known composition and purity. It is added in a known quantity. This responds to the analytical and measurement processes as will the actual substance sample.
This is used to draw a calibration curve with the signals of internal standard on Y axis.
The accuracy of the results is increased as the instrument noise gets eliminated. This is because the signal to noise ratio is the same for the internal standard as for the substance under analysis.
Conclusion
Running the internal standards prior to running the analyte, improves the accuracy of the results. The internal standard, however, is to be properly selected.
Want to see more full solutions like this?
Subscribe now to access step-by-step solutions to millions of textbook problems written by subject matter experts!
Students have asked these similar questions
What would happen if you added the
HCI to the Grignard reagent before
adding benzophenone? Draw a
reaction mechanism to support your
answer.
At 300 K, in the decomposition reaction
of a reactant R into products, several
measurements of the concentration of R
over time have been made (see table).
Calculate the order of the reaction.
t/s
[R]/ (mol L-1)
0
0,5
171
0,16
720
0,05
1400
0,027
Write the correct IUPAC names of the molecules in the picture
Chapter 10 Solutions
Principles of Instrumental Analysis
Knowledge Booster
Similar questions
- How many grams of solid NaCN have to be added to 1.5L of water to dissolve 0.18 mol of Fe(OH)3 in the form Fe(CN)63 - ? ( For simplicity, ignore the reaction of CN - ion with water) Ksp for Fe(OH)3 is 2.8E -39, and Kform for Fe(CN)63 - is 1.0E31arrow_forwardDraw the most stable chair conformation of 1-ethyl-1-methylcyclohexane, clearly showing the axial and equatorial substituents. [4] Draw structures corresponding to the following IUPAC name for each of the following compounds; [5] i) 4-Isopropyl-2,4,5-trimethylheptane ii) trans-1-tert-butyl-4-ethylcyclohexane iii) Cyclobutylcycloheptane iv) cis-1,4-di-isopropylcyclohexane (chair conformation) v) 3-Ethyl-5-isobutylnonanearrow_forwardDraw and name molecules that meet the following descriptions; [4] a) An organic molecule containing 2 sp2 hybridised carbon and 1 sp-hybridised carbon atom. b) A cycloalkene, C7H12, with a tetrasubstituted double bond. Also answer question 2 from the imagearrow_forward
- H 14. Draw the line angle form of the following molecule make sure you use the proper notation to indicate spatial positioning of atoms. F F H 15. Convert the following condensed form to line angle form: (CH3)3CCH2COCH2CON(CH2CH3)2arrow_forwardIn a reaction between two reactants A and B, the half-life is the same for both only if(A) the stoichiometry A:B is 1:1.(B) the stoichiometry A:B is 1:2 or 2:1.arrow_forwardIn a reaction between two reactants A and B, the half-life is the same for both.(1) Only if the stoichiometry A:B is 1:1.(2) If the initial quantities of A and B are in their stoichiometric ratios.arrow_forward
- There are 48 pairs of students in the following table. Each pair has quantitatively determined the mass of taurine in a 250 mL can of the popular energy drink marketed as “Munster” using High Performance Liquid Chromatography (HPLC). The class results are presented below: QUESTION: Calculate the measurement of uncertainty and provide the data in a spreadsheet table. Mass of Taurine (mg) Mass of Taurine (mg) (Table continued) 152.01 152.23 151.87 151.45 154.11 152.64 152.98 153.24 152.88 151.45 153.49 152.48 150.68 152.33 151.52 153.63 152.48 151.68 153.17 153.40 153.77 153.67 152.34 153.16 152.57 153.02 152.86 151.50 151.23 152.57 152.72 151.54 146.47 152.38 152.44 152.54 152.53 152.54 151.32 152.87 151.24 153.26 152.02 152.90 152.87 151.49 152.46 152.58arrow_forward1. Predict the organic product(s) of the following reactions. Assume excess of reagents unless otherwise noted. a) &l BH3 •THF b) 1) NaOH 2) H3O+ solve d) ala 1) EtMgBr 2) H3O+ e) H2N سكر CuLi NH2 1) SOCI2 2) EtMgBr 3) H3O+ NC H3O+ Δarrow_forwardThere are 48 pairs of students in the following table. Each pair has quantitatively determined the mass of taurine in a 250 mL can of the popular energy drink marketed as “Munster” using High Performance Liquid Chromatography (HPLC). The class results are presented below: QUESTION: Summarise and report these results including an indication of measurement uncertainty. In both calculation samples calculate if an outlier is present, max value, number of samples, mean, standard deviation, g (suspect), g (critical) and t (critical). Mass of Taurine (mg) Mass of Taurine (mg) (Table continued) 152.01 152.23 151.87 151.45 154.11 152.64 152.98 153.24 152.88 151.45 153.49 152.48 150.68 152.33 151.52 153.63 152.48 151.68 153.17 153.40 153.77 153.67 152.34 153.16 152.57 153.02 152.86 151.50 151.23 152.57 152.72 151.54 146.47 152.38 152.44 152.54 152.53 152.54 151.32…arrow_forward
- Indicate the rate expressions for reactions that have order 0, 1, and 2.arrow_forwardPROBLEMS Q1) Label the following salts as either acidic, basic, or neutral a) Fe(NOx) c) AlBr b) NH.CH COO d) HCOON (1/2 mark each) e) Fes f) NaBr Q2) What is the pH of a 0.0750 M solution of sulphuric acid?arrow_forward8. Draw all the resonance forms for each of the fling molecules or ions, and indicate the major contributor in each case, or if they are equivalent (45) (2) -PH2 سمة مدarrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
Chemistry for Engineering StudentsChemistryISBN:9781285199023Author:Lawrence S. Brown, Tom HolmePublisher:Cengage Learning
Principles of Instrumental Analysis
Chemistry
ISBN:9781305577213
Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:Cengage Learning
Chemistry for Engineering Students
Chemistry
ISBN:9781285199023
Author:Lawrence S. Brown, Tom Holme
Publisher:Cengage Learning