Question

Under what conditions can the second term in Equation 32-23 be ignored?

Short answer

The second term of the equation $m_i$ has a very small value because a very small amount of radioactive tracer is required for the detectable activity of the mixture. Hence this term is ignored.

Step-by-step solution

Given information

Determine the conditions in which the second term of the following equation is ignored.

$m_x=\frac{R_t}{R_S}\times m_m-m_l$

Explanation

The given equation is the equation for the isotope dilution method which is represented as-

$m_x=\frac{R_t}{R_S}\times m_m-m_l$

Where,

$m_x=$mass of inactive sample

$R_t=$counting rate

$R_m=$counting rate of inactive analyte

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

$m_t=$mass of radioactive tracer

The condition in which the second term of isotope dilution method equation is ignored is given below-

The counting rate of mixture $R_m$can be measured easily when the radioactive tracer has very high activity at this condition very small amount of tracer is sufficient for the detectable activity of the mixture. This

condition results in the small value of the mass of tracer $m_t$, therefore the second term of the equation is ignored.