Studies of Analyte Particle Transport in a Particle Beam-Hollow Cathode Atomic Emission Spectrometry System

Simultaneous multielement detection in particle beam/hollow cathode-optical emission spectroscopy

“…The optimum temperatures observed here are appreciably higher than previous works (∼ 200°C) [10,11,16,19,20]. This difference can be attributed to the source block geometry changes and the size and amount of boron nitride used in the new design of the thermoblock.…”

“…While it is easy to suggest that higher temperatures would be desirable, temperatures could not exceed 500°C due to melting of the Teflon O-ring used in the top of the HC source block, causing loss of vacuum integrity. In addition, temperatures exceeding 500°C would also be expected to yield a decrease in analyte response for organic species due to pyrolysis [10,11,16,19,20]. Further refinement may be required to efficiently detect inorganic and organic (metal and nonmetal) species simultaneously.…”

“…The concentration of LODs is somewhat higher than metals by inductively coupled plasma (ICP)-OES [32,33]. Additionally, previous studies have shown that enhanced sensitivity can be achieved with the PB/HC-OES when using solutions with added carrier salts for example 100 μg mL − 1 KCl [15,20]. A comparison of the detection limits for iron using ICP-OES and the PB/HC-OES system found that LODs that were 0.9 ng mL − 1 and 41.9 ng mL − 1 , respectively [18].…”

“…It has been previously shown that vaporization from the HC walls is the primary means of generating gas-phase species in the PB/HC-OES system [16,19]. Optimal HC temperatures have ranged from 200-300°C, with higher temperatures leading to pyrolysis of carbonaceous samples [10,11,16,19,20]. Given the difference in the placement of the heaters and thermocouples in the new design, it was imperative to characterize the role of "measured" temperature on the analyte responses.…”

“…This spray enters the desolvation chamber, which is wrapped with heating tape for variable temperature control. The particle-containing gas stream is then introduced into a two-stage momentum separator that removes low mass gas molecules (solvent and He nebulizer gas), delivering dry analyte particles (<10 μm size [19,20]) to the HC source volume.…”