A SIMULTANEOUS MULTIELEMENT ATOMIC-ABSORPTION SPECTROMETER WITH AN INVERSE POLYCHROMATOR AND FAST FOURIER TRANSFORMATION

A new type of atomic absorption spectrometer was developed for simultaneous determinations of up to 10 elements. The radiation from several hollow cathode lamps strikes a plane grating at different incident angles, which were set so that the rays of the analytical line from the hollow cathode lamps will merge into a single beam. The incident angles were calculated from the grating equation. The discharge currents of the hollow cathode lamps were sinusoidally modulated at different frequencies. The atomic absorption signals from a photomultiplier tube (PMT) were discriminated through fast Fourier transformation (FFT). The analytical performances were evaluated for simultaneous determinations of up to 10 elements in test solutions and in mandarin orange juice by means of electrothermal atomization.