Spectral interference deals:

The second kind of spectral interference deals along with spectral lines of two or more elements that are close but their spectra do not overlap. This kind of interference becomes a problem while a filter is used as the device to isolate spectral lines. A filter might permit spectral lines separated through 5.0-10.0 nm to pass through, therefore resulting within an error in the analysis. Such interferences could be reduced through increasing the resolution of the spectral isolation system. Therefore, the interference cannot be eliminated entirely because of the finite width of the spectral isolation system and the finite slit width within such systems.

A third kind of spectral interference occurs because of the presence of continuous background that arises because of high concentration of salts within the sample, especially of alkali and alkaline earth metals. A few organic solvents also generate a continuous background. This kind of interference could be corrected through using suitable scanning method.