A New Dual Wave-Length Spectrophotometer

Abstract

The design, construction, specifications, and operation of a new dual wave-length spectrophotometer are presented. The instrument utilizes only one fixed grating and mobile exit slits with photomultiplier light sensors. Two wave lengths can be monitored and both channels may be scanned, simultaneously and independently. The spectrophotometer has been integrated into an atomic absorption system which includes a Woodriff furnace and Ithaco dual channel lock-in amplifier. The two channels may be used separately (A and B) or may be ratioed (A/B). Calibration curves were obtained for Ag and Pb. Results are given for the determination of Ag in a complex water sample requiring background correction using the ratio (A/B) mode and for the simultaneous determination of Ag and Pb in synthetic samples using the two separate channel (A and B) mode.