Ultraviolet Quartz Acousto-Optic Tunable Filter Wavelength Selection for Inductively Coupled Plasma Atomic Emission Spectrometry

Abstract

A quartz acousto-optic tunable filter (AOTF) is utilized as a wavelength selection device for inductively coupled plasma atomic emission spectrometry (ICP-AES). System design is detailed. Fundamental characterizations indicate that the useful spectral range exceeds the 206 to 405 nm range. Wavelength calibration is extremely accurate with the correlation coefficient of the ICP atomic emission wavelength/inverse frequency plot exceeding 0.999999. Bandpasses were measured as 0.06 nm at 226 nm and 0.36 nm at 405 nm. These values are comparable to those of a moderate-resolution monochromator. The system was characterized with 12 metals: Ag, Ba, Ca, Cd, Cr, Cu, Eu, Fe, Hg, Mg, Mn, and Pb. Detection limits are in the single to tens of ng/mL range for many metals. Linearity is demonstrated from lower concentration ranges near the detection limit.