Peak Fitting and Deconvolution for Determination of the Impulse Response Function of the Sample Introduction System in Flow Injection Inductively Coupled Plasma Spectrometry

A technique for determining the impulse response function for an inductively coupled plasma atomic emission spectrometry sample introduction system is demonstrated. The input response function may then be useful for the determination of outputs, and consequently the performances, of flow injection or other sample treatment systems, which precede the sample introduction system. In a procedure to generate a known input response, a bolus of analyte was proceeded and followed by an air bubble, which reduced dispersion to a minimum. The impulse response function was determined and used to deconvolute other inputs of known concentration and dispersion. The deconvolution of the outputs using the impulse response function returned the expected result, indicating that the technique and impulse response function were correct. When used with an unsegmented traditional flow injection sample introduction valve, the system demonstrated clearly that significant dispersion takes place even in very compact introduction arrangements.