What is the purpose of using a blank sample in analytical chemistry?

The use of a blank sample in analytical chemistry primarily serves to ensure the reliability of results by accounting for impurities and background signals. A blank sample is typically prepared in the same way as the test samples but does not contain the analyte of interest. This allows for the identification of any contributions from the solvent, reagents, and the equipment itself that might interfere with the analysis. By measuring the blank and subtracting its signal from that of the sample, analysts can obtain a more accurate representation of the analyte concentration.

Using a blank helps in correcting for baseline noise or other systematic errors that might arise during the measurement process, ensuring that the reported results reflect true analyte concentrations rather than artifacts or interferences. Therefore, incorporating a blank is a crucial step in validating the reliability and accuracy of analytical measurements.