REAL-TIME ATOM RESIDENCE TIME COMPENSATION IN CHEMICAL-VAPOR GENERATION ATOMIC SPECTROMETRY - A MORE PRECISE ANALYTICAL SIGNAL

Batch chemical vapor generation techniques, using flow-through optical cells for the spectrochemical determination of mercury, produce trans ient signals whose peak area generally varies inversely as a function of the carrier gas now rate. One significant source of within-and betw een-day signal variability is the vacillation of the carrier gas now r ate. Methods are presented to compensate for this variability by separ ately performing signal compensation in postacquisition and real-time modes. These methods involve processing the transient absorbance or fl uorescence and the carrier gas now rate data to produce new analytical signals. Results are presented demonstrating improved signal precisio n (reproducibility), from 31 to 4.4% (CV, n = 10), for the cold-vapor atomic absorption and atomic fluorescence determination of mercury.