What phenomenon occurs when contamination of a sample is caused by the preceding sample?

Carryover is the phenomenon where contamination of a sample is caused by residual material from a preceding sample. This often occurs in analytical procedures where equipment, containers, or other surfaces may not be adequately cleaned between tests. As a result, trace amounts of the previous sample can affect the results of the subsequent analysis, leading to inaccurate outcomes. This type of contamination is critical to recognize, as it can happen in laboratory settings that deal with sensitive quantifications or trace analyses, potentially leading to significant errors in results.

In contrast, crossover contamination typically refers to situations where there is direct transfer or mixing of samples during the handling process, rather than merely residual contamination from the preceding sample. Sample interference denotes the impact of one substance on the measurement of another, while reagent contamination involves impurities from the chemicals used in the analytical procedure, both of which are distinct from carryover.