What is a blank solution used for in spectrophotometry?

In spectrophotometry, a blank solution is primarily used to calibrate the spectrophotometer to zero. This process involves filling a cuvette with the blank solution, which typically contains all the components of the sample except the analyte of interest. By measuring the absorbance of the blank, the system can account for any light absorption that occurs due to the solvent or other reagents in the solution, ensuring that only the absorbance due to the analyte is measured thereafter.

Calibrating to zero is crucial because it establishes a baseline, allowing for accurate measurement of the sample solutions. It ensures that the readings taken of the analyte reflect only its absorbance, free from any interference caused by the blank solution.