A miniature planar magnetron glow discharge source for analysis of submicroliter volume aqueous samples using atomic emission spectroscopy

A miniature planar magnetron glow discharge source with a chamber volume of 60 ml has been designed and evaluated for the analysis of less than 1 μl of aqueous samples by atomic emission spectroscopy. Limits of detection for magnesium, silver, boron, europium and copper in the presence of a magnetic field are observed to be 3 to 40 times lower than for the source without a magnetic field when the measurements are made under the compromised discharge conditions for each type of source. Emission intensity in the presence of the magnetic field is found to increase as a square function of the discharge current. The improved detection limits for the magnetically enhanced glow discharge source are attributed to the increased current density of the discharge in the presence of the magnetic field which formed a plasma ring localized above the cathode surface. An RSD in the range 15–25% is observed for these measurements.