A Rowland Circle, multielement graphite furnace atomic absorption spectrometer

A simultaneous, multielement atomic absorption spectrometer utilizing a gra phite furnace atomizer was constructed and evaluated. The optical arrangeme nt employs a concave grating to combine the spectral output from a deuteriu m lamp and four hollow cathode lamps that are placed on the perimeter of a Rowland Circle. A graphite furnace atomizer is positioned on the circle at the point of convergence of the five light sources. Background correction i s performed by the continuum source method. Simultaneous detection of the a nalyte absorption signals is accomplished with a charged-coupled device. Fo ur test elements were used for evaluation purposes: cadmium, lead, copper a nd chromium. Even though the elements differ greatly in volatility, the det ection limits approach the values published for single element GFAAS: 4, 12 , 14 and 12 pg for Cd, Pb, Cu and Cr, respectively. The characteristic mass es (integrated absorbance) for the four metals are 3, 24, 14 and 7 pg, resp ectively. Three drinking water reference materials an analyzed: NIST SRM #1 643b (Trace Elements in Water), Fisher Scientific "Metals Drinking Water St andard," and High Purity Standards "Drinking Water Metals Solution A and B" . The determined amounts were within 10% of the certified values for each o f the four elements for all three reference materials. (C) 1998 Elsevier Sc ience B.V. All rights reserved.