Multipe peaks in FTIR tests can indicate the presence of multiple compounds in a sample. The peaks can be used to identify the compounds present in the sample and to determine the relative concentrations of each compound. The peaks can also be used to determine the functional groups present in the sample, such as alcohols, aldehydes, ketones, carboxylic acids, amines, and amides. The relative intensity of the peaks can also be used to determine the relative concentrations of each compound.