Question

GenAlex Medical, a leading manufacturer of medical laboratory equipment, is designing a new automated system that can detect therapeutic levels of dissolved theophylline (10. to 20./μgmL), using a blood sample that is as small as 4.0mL. Calculate the minimum mass in milligrams of theophylline that the new system must be able to detect. Round your answer to 2 significant digits.

Answer 1

Minimum detection level = 10 $\mu$g/mL.

In 4.0 mL miniumum mass present

= 4.0 (mL) × 10 ($\mu$g/mL)

= 40 $\mu$g.

Now, 1 mg = 1000 $\mu$g

So, miniumum mass in miligrams of theophyline that the new system must be able to detect

= 40 $\mu$g × (1mg/1000$\mu$g)

= 0.04 mg.

= 4.0×10^-2 mg. ( 2 significant digits)