Question

Why is it desirable in the method of standard addition to add a small volume of concentrated standard rather than a large volume of dilute standard?

Short answer

• The large volume of dilute standard will alter the concentration of the matrix and will possibly result to matrix effect.

• The addition of diluted standards may also cause a difficulty in detection.

• The large volume of dilute standard may also affect the sensitivity of the instruments being used.

• The measurements made will be nearly similar to each other when only a small volume of concentrated standard is added.

Step-by-step solution

Step 1:Concentrated and dilute standard definition

• A standard solution is a solution that has a precisely known concentration of an element or compound in analytical chemistry.
• A dilution is a solution that decreases the concentration of a solute by adding additional solvent to a more concentrated solution (stock solution).

Key points

There are a couple of reasons why it is desirable to add only a small volume of concentrated standard rather than a large volume of dilute standard:

• The large volume of dilute standard will alter the concentration of the matrix and will possibly result to matrix effect.

• The addition of diluted standards may also cause a difficulty in detection.

• The large volume of dilute standard may also affect the sensitivity of the instruments being used.

• The measurements made will be nearly similar to each other when only a small volume of concentrated standard is added.