While measuring the potassium concentration in a drug formulation, the technologist took 10 µl of the sample and mixed it with 90 µl of test buffer.…
While measuring the potassium concentration in a drug formulation, the technologist took 10 µl of the sample and mixed it with 90 µl of test buffer. From the resulting solution, he took 5 µl and measured its total potassium content as 25 ng. What would be the concentration of potassium in the drug formulation?
Select an option to attempt
Correct Answer: Option A
Explanation
Serial dilution and concentration calculation:Step 1 — Dilution: 10 µL sample + 90 µL buffer = 100 µL total → dilution factor = 10 (i.e., 1:10 dilution).Step 2 — Concentration in diluted solution: 5 µL of diluted sample contains 25 ng, so:Step 3 — Back-calculate original concentration:Answer: 50 ng/µL (Option 1).