In-situ droplet monitoring for self-tuning spectrometers

Patent · Tue Sep 28 00:00:00 EDT 2010

OSTI ID:1014555

Montaser, Akbar ^[1]; Jorabchi, Kaveh ^[2]; Kahen, Kaveh ^[3]

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1. Potomac, MD
2. Arlington, VA
3. Kleinburg, CA

A laser scattering based imaging technique is utilized in order to visualize the aerosol droplets in an inductively coupled plasma (ICP) torch from an aerosol source to the site of analytical measurements. The resulting snapshots provide key information about the spatial distribution of the aerosol introduced by direct and indirect injection devices: 1) a direct injection high efficiency nebulizer (DIHEN); 2) a large-bore DIHEN (LB-DIHEN); and 3) a PFA microflow nebulizer with a PFA Scott-type spray chamber. Moreover, particle image velocimetry (PIV) is used to study the in-situ behavior of the aerosol before interaction with, for example, plasma, while the individual surviving droplets are explored by particle tracking velocimetry (PTV). Further, the velocity distribution of the surviving droplets demonstrates the importance of the initial droplet velocities in complete desolvation of the aerosol for optimum analytical performance in ICP spectrometries. These new observations are important in the design of the next-generation direct injection devices for lower sample consumption, higher sensitivity, lower noise levels, suppressed matrix effects, and for developing smart spectrometers. For example, a controller can be provided to control the output of the aerosol source by controlling the configuration of the source or the gas flow rate via feedback information concerning the aerosol.

• Research Organization: The George Washington University (Washington, DC)
• Sponsoring Organization: USDOE
• DOE Contract Number: FG02-93ER14320
• Assignee: The George Washington University (Washington, DC)
• Patent Number(s): 7,804,064
• Application Number: US Patent Application 11/240,642
• OSTI ID: 1014555
• Country of Publication: United States
• Language: English