In the determination of lead content in a solid food sample, 1 g of the solid food sample was extracted with 10 mL of solvent and then diluted to a final volume of 50 mL. A calibration plot of lead standards was obtained from the standard solutions of 1 to 50 ug/mL and it gave a linear regression line of y = 0.025x+0.004. The wavelength for lead analysis is 283.3 nm. The absorbance value for the extract was 0.302 arbitrary units. Calculate the percentage of Pb in 1 g of the solid food sample.

In the determination of lead content in a solid food sample, 1 g of the solid food sample was extracted with 10 mL of solvent and then diluted to a final volume of 50 mL. A calibration plot of lead standards was obtained from the standard solutions of 1 to 50 ug/mL and it gave a linear regression line of y = 0.025x+0.004. The wavelength for lead analysis is 283.3 nm. The absorbance value for the extract was 0.302 arbitrary units. Calculate the percentage of Pb in 1 g of the solid food sample.

Principles of Instrumental Analysis

7th Edition

ISBN:9781305577213

Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Chapter9: Atomic Absorption And Atomic Fluorescence Spectrometry

Section: Chapter Questions

Problem 9.21QAP

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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.
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