How can an analytical chemist remove substances that interfere with a measurement?

In analytical chemistry, an interference is any substance other than the analyte that can be measured by the chosen method or that prevents the analyte from being measured, leading to erroneous results. To ensure accurate measurements, chemists employ various separation and purification techniques to isolate the analyte or remove these interferences.12

Common methods for interference removal include:

• Distillation: Used to separate volatile species from a mixture, often requiring specialized apparatus for collection.13
• Extraction: Takes advantage of the relative solubilities of solutes in two immiscible solvents, allowing the analyte or interferent to migrate into a separate phase.14
• Chromatography: A powerful technique that separates components based on their distribution between a stationary phase and a mobile phase.5
• Precipitation: Involves forming a low-solubility product that can be filtered out of the solution.3
• Centrifugation: Uses centrifugal force to separate suspended particles or immiscible liquids based on density differences.67
• Masking: Chemical reagents are added to convert interferents into non-reactive or non-extractable species without removing them physically.23
• Other techniques: Methods such as filtration, complexation, osmosis, and electrogravimetry are also utilized depending on the sample matrix.1