An electrothermal vaporization flame atomic emission spectrometer

Abstract

An inexpensively built, light-weight, potentially transportable flame atomic emission spectrometry device has been designed and developed. A tungsten coil is employed as an electrothermal vaporization source coupled to an oxygen-acetylene flame. The tungsten coil is simple in design and commercially available as a 150 W, 15 V light bulb, while the flame source is generated by a welder's metal-cutting torch. Nineteen elements have been determined with limits of detection as low as 0.9 ng L⁻¹ for Ca and 8.0 ng L⁻¹ for In. The accuracy of the method is verified by determining the concentration of thirteen elements in two reference materials: Montana soil and a water pollution standard solution. No statistically significant difference is observed between the certified and determined values at a 95% level of confidence. Sample volumes as low as 10 μL may be analyzed. The best torch tip design is identified, and gas flow rates are optimized. The temperature profile of the flame is also discussed. The electrothermal vaporizer and cutting torch are designed to be portable. Incorporation of a simple hand-held CCD spectrometer would render the entire system usable in the field.