Chapter 32, Problem 32.15QAP

Interpretation Introduction

Interpretation:

In a mixture, penicillin is determined by mixing of ${}^{14}C$ labeled compound of amount 0.981mg. The specific activity of ${}^{14}C$ labeled compound is $5.42\times {10}^{3}cpm/mg$. The pure crystalline penicillin of amount 0.406mg was isolated after the equilibrium state. The net activity of the material is 343cpm. The mass of the penicillin in the sample is to be determined.

Concept introduction:

The mass of the penicillin is calculated by the following formula-

$m_x=\frac{R_t}{R_m}\times m_m-m_t$ ………………… (1)

Where,

$m_x$ = mass of inactive sample

$R_t$ = counting rate

$R_m$ = counting rate of inactive analyte

$m_m$ = isolated mass which is purified from the mixture of radioactive tracer

$m_t$ = mass of radioactive tracer