SENSITIVITIES AND DETECTION LIMITS FOR GRAPHITE-FURNACE ATOMIC-ABSORPTION SPECTROMETRY USING A CONTINUUM SOURCE AND LINEAR PHOTODIODE-ARRAY DETECTION

Analytical figures of merit have been examined for a series of elements (As, Cd, Co, Cu, Fe, Mn, Ni, Pb, Se, Sn, and Zn) using graphite furnace atomic absorption spectrometry (GFAAS) with a continuum source and a linear photodiode array detector. Intrinsic masses, mi were calculated for continuum source AAS based on wavelength and time integrated absorbance in units of pm-s. A simple triangular model, based on experimental values for the hollow cathode lamp linewidths and calculated widths for the absorption profiles, was used to compute mi values from tabulated characteristic mass values for conventional AAS. With the exception of As and Se, the mi values for continuum source and conventional AAS agreed within a factor of two. Continuum source detection limits obtained were similar to those reported for line source GFAAS. Two standard reference materials were analyzed and values for the elements studied were found to be in good agreement with the certified values.