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.

Inductively coupled plasma chemistry examinations with visible acousto-optic tunable filter hyperspectral imaging

“…AOTFs may exhibit image degradation due to imperfectly collimated light and image shift with changing wavelength. 21,24 Eight pixels were selected across the HCL image for image shifting examination. The image shift was about 1.75 pixel/ MHz (or about 0.88 pixel/nm) in this wavelength region.…”

“…An ultrasonic nebulizer (USN, CETAC Technology Inc., Omaha, NE, Model U5000) was used for sample introduction. A peristaltic pump (Rainin Instrument Co. Inc., Woburn, MA) was used to deliver 0.6 mL min 21 aqueous samples to the USN and remove waste solvent from the aerosol chamber. The USN Ar carrier gas was generally maintained at a flow rate of 0.92 L min 21 , but varied to examine flow rate effects.…”

“…A peristaltic pump (Rainin Instrument Co. Inc., Woburn, MA) was used to deliver 0.6 mL min 21 aqueous samples to the USN and remove waste solvent from the aerosol chamber. The USN Ar carrier gas was generally maintained at a flow rate of 0.92 L min 21 , but varied to examine flow rate effects. The plasma Ar coolant flow rate was maintained at 12 L min 21 .…”

“…The USN Ar carrier gas was generally maintained at a flow rate of 0.92 L min 21 , but varied to examine flow rate effects. The plasma Ar coolant flow rate was maintained at 12 L min 21 . Radiation from the plasma was directed by a flat mirror and the beam waist was reduced for AOTF introduction with a 5 cm focal length fused silica lens (Oriel Corp., Stratford, CT).…”

“…Sample solutions (100 mg mL 21 ) of Ca, Cr, Mg, Li, Sr and Na were nebulized while using a constant USN carrier gas flow rate of 0.92 L min 21 . The Ar coolant flow rate was maintained at 12 L min 21 , the liquid sample delivery rate was set at 0.60 mL min 21 . Fig.…”