TY - JOUR
T1 - Roles of electrode material and geometry in liquid sampling-atmospheric pressure glow discharge (LS-APGD) microplasma emission spectroscopy
AU - Quarles, C. Derrick
AU - Manard, Benjamin T.
AU - Burdette, Carolyn Q.
AU - Marcus, R. Kenneth
PY - 2012/11
Y1 - 2012/11
N2 - The roles of the electrode material and geometry on the performance of the liquid sampling-atmospheric pressure glow discharge (LS-APGD) optical emission spectroscopy source are described. The LS-APGD source has been interfaced to a high resolution JY RF-5000 polychromator allowing for simultaneous multiple element detection. This LS-APGD source operates at currents of 20-60mA and solution flow rates of 0.1-0.4mLmin -1. A glow discharge is generated between the surface of the electrolyte test solution exiting a glass capillary and the end of a metallic counterelectrode. Described here is an evaluation of how the counterelectrode material identity (copper, nickel, and stainless steel) and the electrode configuration (geometry) influence the analyte emission responses for a test solution containing Ag, Cr, Cu, Mg, Ni, and Zn in 1M HNO 3. Studies of the effect of liquid flow rates reveal that 0.3mLmin -1 provides optimal analyte emission responses as it relates to peak intensity, peak area, and peak widths. Use of nickel as the counterelectrode material provided the best reproducibility for analyte emission responses with 8.9-13.0%RSDs for 50μL injections of 100μgmL -1 test solutions, while copper and stainless steel electrodes had %RSDs of 3-5 times higher than the nickel electrode. The role of the electrode geometries were evaluated previously-used 180° (co-linear) arrangement as well as for different configurations with the electrodes mounted at 90° with respect to each other, with the most intense optical emission responses found for the 180° geometry. Solution-based limits of detection (LOD) were found to be in the range of 0.44-0.93μgmL -1 for Ag, Cu, Mg, Ni, and Zn using the nickel electrode at the 180° geometry. Based on the use of 50μL injections, this represents absolute detection limits of 22-46ng. LODs were approximately an order of magnitude higher for the copper and stainless steel electrodes.
AB - The roles of the electrode material and geometry on the performance of the liquid sampling-atmospheric pressure glow discharge (LS-APGD) optical emission spectroscopy source are described. The LS-APGD source has been interfaced to a high resolution JY RF-5000 polychromator allowing for simultaneous multiple element detection. This LS-APGD source operates at currents of 20-60mA and solution flow rates of 0.1-0.4mLmin -1. A glow discharge is generated between the surface of the electrolyte test solution exiting a glass capillary and the end of a metallic counterelectrode. Described here is an evaluation of how the counterelectrode material identity (copper, nickel, and stainless steel) and the electrode configuration (geometry) influence the analyte emission responses for a test solution containing Ag, Cr, Cu, Mg, Ni, and Zn in 1M HNO 3. Studies of the effect of liquid flow rates reveal that 0.3mLmin -1 provides optimal analyte emission responses as it relates to peak intensity, peak area, and peak widths. Use of nickel as the counterelectrode material provided the best reproducibility for analyte emission responses with 8.9-13.0%RSDs for 50μL injections of 100μgmL -1 test solutions, while copper and stainless steel electrodes had %RSDs of 3-5 times higher than the nickel electrode. The role of the electrode geometries were evaluated previously-used 180° (co-linear) arrangement as well as for different configurations with the electrodes mounted at 90° with respect to each other, with the most intense optical emission responses found for the 180° geometry. Solution-based limits of detection (LOD) were found to be in the range of 0.44-0.93μgmL -1 for Ag, Cu, Mg, Ni, and Zn using the nickel electrode at the 180° geometry. Based on the use of 50μL injections, this represents absolute detection limits of 22-46ng. LODs were approximately an order of magnitude higher for the copper and stainless steel electrodes.
KW - Electrode material
KW - Liquid sampling-atmospheric pressure glow discharge (LS-APGD)
KW - Microplasma
KW - Optical emission spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=84867856723&partnerID=8YFLogxK
U2 - 10.1016/j.microc.2012.01.012
DO - 10.1016/j.microc.2012.01.012
M3 - Article
AN - SCOPUS:84867856723
SN - 0026-265X
VL - 105
SP - 48
EP - 55
JO - Microchemical Journal
JF - Microchemical Journal
ER -