Principles of Instrumental Analysis
7th Edition
ISBN: 9781305577213
Author: Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher: Cengage Learning
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Question
Chapter 15, Problem 15.9QAP
Interpretation Introduction
Interpretation:
The mass in milligrams of quinine in the tablet should be determined.
Concept introduction:
The amount of quinine is the product of concentration of quinine and the ratio of the fluorescent intensity of the sample and the fluorescent intensity of the dilute sample.
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Quinine in a 1.553-g antimalarial tablet was dissolved in sufficient 0.10 M HCl to give 250 mL of solution.A 10.00-mL aliquot was then diluted to 50.00 mL with the acid. The fluorescence intensity for the dilutedsample at 347.5 nm provided a reading of 196 on an arbitrary scale. A standard 100-ppm quinine solutionregistered 125 when measured under conditions identical to those for the diluted sample. Calculate the massin milligrams of quinine in the tablet.
A student wanted to determine the level of lead in amoxicillin powder, so he
transferred 148 mg of the powder to 200 ml volumetric flask and completed
the volume volumetrically, then he transferred 5 ml of the obtained solution to
50 ml volumetric flask and completed the volume properly, and read the
absorbance of the obtained solution on AAS. The reading was 0.48. and the
calibration equation was: "Y =12.25 x- 0.05" (concentration microg./mL).
?"Calculate the content of lead in amoxicillin as "ppm
326.5.a O
605.0 .b O
60.5.c O
17.5.d O
584.7.e O
أخل اختياري
Exactly 5.00 mL aliquots of a
solution containing analyte X were
transferred into 50.00-mL
volumetric flasks and the pH of
the solution is adjusted to 9.0. The
following volumes of a standard
solution containing 2.00 µg/mL of
X were then added into each flask
and the mixture was diluted to
volume: 0.000, 0.500, 1.00, 1.50
and 2.00 mL. The fluorescence of
each of these solutions was
measured with a fluorometer, and
the following values were
obtained: 3.26, 4.80, 6.42, 8.02
and 9.56, respectively.
ii. Using relevant functions in
Excel, derive a
least-squares equation for
the data, and use the
parameters of this
equation to find the
concentration of the
phenobarbital in the
unknown solution.
Chapter 15 Solutions
Principles of Instrumental Analysis
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- A student wanted to determine the level of lead in amoxicillin powder, so he transferred 148 mg of the powder to 200 ml volumetric flask and completed the volume volumetrically, then he transferred 5 ml of the obtained solution to 50 ml volumetric flask and completed the volume properly, and read the absorbance of the obtained solution on AAS. The reading was 0.48. and the calibration equation was: "Y =12.25 x- 0.05" (concentration microg./mL). Calculate the content of lead in amoxicillin as "ppm"? O a. 326.5 O b. 605.0arrow_forwardTo quantify the Cadmium content in a water sample, 5 aliquots of 10 mL were taken, adding to each one of them a volume of a standard solution of Cd (2 mg / mL); after the addition the final volume for all solutions was 50 mL. The absorbance reading was taken in an Atomic Absorption spectrophotometer, the data recorded were: Aliquot 1 2 3 4 5 Cd solution (mL) 0 1 2 3 4 Absorbance 0.163 0.240 0.319 0.402 0.478 Calculate the ppm of Cd.arrow_forwardTo determine the content of Pb in a canned sausage, 5.00 g were weighed and after adequate treatment they were gauged to a volume of 100 mL, from there an aliquot of 2 mL was taken and brought to a volume of 250 mL. The readings of a series and of the sample were taken in an Atomic Absorption spectrophotometer, recording the following data: mg Pb/mL 0 1 2 3 4 Sample Absorbance 0.00 0.15 0.29 0.44 0.58 0.38 What is the% Pb in canned sausage?arrow_forward
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