Chapter 9, Problem 9.20QAP

Interpretation Introduction

Interpretation:

Precipitate protein is obtained by treating 5.00 mL sample of blood with trichloroacetic acid. The final solution has pH of 3 and this solution is extracted with two portions of 5 ml of methyl isobutyl ketone APCD that is an organic lead complex agent, this whole process is done after centrifugation. Absorbance of 0.454 at 283.3nm is obtained when the extracted solution is reacted directly with air-acetylene flame. In the same way, absorbance of 0.412 and 0.642 is obtained by treating 5mL aliquots standard solution of 0.240 ppm and 0.475 ppm of Pb. Concentration of Pb in ppm needs to be calculated by following the Beer’s law.

Concept introduction:

Beer Lambert law gives the relationship between absorbance and concentration of a sample. For the calculation of concentration, the following the equation of straight line as follows:

$y=mx+c$

Where,

y = absorbance

x = concentration of sample

m is slope of graph plotted between absorbance and concentration of the sample.

And,

C is intercept of the graph.