Analyse von Flüssigkeiten in der Hohlkathode

Investigation of the role of hollow cathode (vaporization) temperature on the performance of particle beam-hollow cathode atomic emission spectrometry (PB-HC-AES)

“…A dc potential difference applied across the stainless-steel tubing resulted in resistive heating along the tube, producing a thermal component to the aerosol formation. Helium gas ¯owed (#360 mL min 21 ) through the gap between the central fusedsilica capillary and outer stainless-steel tubing as a sheath gas to improve heat conduction and to promote the breakup of the liquid at the capillary tip (i.e., pneumatic nebulization). The resulting ®ne aerosol was directed into a steel spray chamber wrapped in heating tape (150±200 ³C).…”

“…A layer of aluminum foil was fastened around a stainless-steel support (3462.660.2 mm) and inserted into the center of the hollow cathode, perpendicular to the incoming beam of particles, for optimum analyte particle collection ef®ciency. Each solutionphase sample containing 20 ppm Cu was introduced in a continuous-¯ow mode at 1.5 mL min 21 for a period of 15 min to allow for a suf®cient amount of analyte particles to accumulate on the aluminum collector. To reduce the absorption of moisture from the atmosphere, each collector was stored in an oven at 100 ³C after sampling, then placed in a desiccator for transport to the scanning electron microscope.…”

“…Differential pumping of the momentum separator provides enrichment of the analyte through removal of solvent, as well as reduction of pressure to match the vacuum requirements of the detection source. Removal of solvent before analyte introduction into the GD source also helps to avoid problems with band emission and signal perturbations caused by the presence of water vapor in the glow discharge, 21,22 because the low pressures and powers employed in the GD are inherently inef®cient for the desolvation and vaporization of liquid samples in comparison with atmospheric pressure ¯ames and plasmas.…”

Pulsed glow discharge in thin-walled metallic hollow cathode. Analytical possibilities in atomic and mass spectrometry

“…30,31 In the case of solution analysis, however, the presence of water in ''dry residue'' may lead to essential deterioration of the analytical signal, especially in mass spectrometry. 32,33 There are some methods to avoid interferences induced by water: liquid chromatographic separation of analyte from solvent before introduction into a GD source; 34 application of electric arc pretreatment eliminating water from residue; or using an argon-hydrogen/argon-methane mixture as the discharge gas in a GD cell. 35 In almost all applications of GD in atomic spectrometry a Grimm-type glow discharge is used.…”

Spektralapparate: Zusatzgeräte für den Emissionsbetrieb

“…Im Routinebetrieb zeichnen sich Untersuchungen mit der Glimmlampe an kompakten, metallischen Proben durch ihre schnelle Durchführbarkeit bei ausreichender Genauigkeit aus. [68][69][70][71][72][73][74][75][76][77][78] Bevor die Möglichkeit gefunden wurde, Nichtleiter und pulverige Substanzen mit der Glimmlampe zu analysieren, stand dafür die Hohlkathodenlampe zur Verfügung. Neben einer Anzahl von Eigenkonstruktionen [68 -72,78] Sowohl für die qualitative als auch quantitative Analyse ist die Hohlkathodenlampe gleichermaßen geeignet.…”