ATOMIC-ABSORPTION MEASUREMENTS IN AN INDUCTIVELY-COUPLED PLASMA USINGSPATIAL-DISPERSION OF THE PLASMA IMAGE

An optical design is presented for inductively coupled plasma atomic a bsorption spectroscopy (ICP-AAS). In this configuration, a see-through ICP torch is oriented co-axially along the optical asis, Incident rad iation from a hollow cathode lamp (HCL) is collimated and passed throu gh the center of the plasma, The plasma is located at a distance less than the focal length of the camera lens while the monochromator was p ositioned at its focal length, This results in the efficient transfer of the HCL radiation while minimizing the amount of ICP emission reach ing the PMT detector through the dispersion of the background and plas ma emission, Solutions containing Ag, Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Ph, Tl and Zn were analyzed both individually and collectively with a background concentration of 1000 mg l(-1) uranium, For comparison purp oses the same solutions were analyzed with a commercial (radial viewin g) ICP-AES instrument, Comparing the detection limits for each element in the multi-element solution with the single element solution, no si gnificant degradation can be seen, This is in comparison to a degradat ion of measured detection limits for emission by a factor of 423 for t he same solutions, Aluminum in the multi-element solution was found to give a poor response on both the ICP-AAS and ICP-AES.