Detection of aqueous metals using a microglow discharge atomic emission sensor

In this study, an atmospheric pressure open-air microglow discharge atomic emission sensor has been used to qualitatively and quantitatively determine selected aqueous metal analytes. The microglow source utilizes a high purity graphite anode, while the non-flowing electrolyte solution itself acts as the cathode. Emission is monitored using a commercial fiber optic-based spectrometer. The microglow sensor has been used to qualitatively determine 20 environmentally relevant metal analytes (Li, Be, B, Na, Mg, Al, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ag, Cd, Ba, Tl and Pb). The technique shows relatively low background emission, except in the wavelength range of 280-390 nm. Quantitative determination of sodium was also conducted with and without the use of an internal standard. The potassium internal standard improved the precision of the technique and resulted in detection limits that were approximately a factor of two lower than without the correction.