Washington University

Other

The United States of America As Represented by the Department of Health

Research, Incorporated

Akbar Montaser

Kaveh Kahen

William F Rutkowski

Kaveh Jorabchi

Craig Steven Westphal

Robert H Clifford

Scott P Dolan

Stephen G Capar

Billy W Acon

Raymond L Van Hoven

John A McLean

Shi-Kit Chan

Jerold M Kacsir

An artificial cigarette, inhaler or other nebulizer device may include a housing, an air passage into the housing, a fog generator chamber within the housing connected to the air passage, a liquid source connected to the fog generating chamber, and a fog generator within the fog generating chamber for receiving liquid from the liquid source and creating an aerosol. The fog generator may be an ultrasonic nebulizer and/or a pneumatic nebulizer.

Nebulizer method

Artificial smoke cigarette

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.

In-situ droplet monitoring for self-tuning spectrometers

Nozzles and nebulizers able to produce aerosol with optimum and reproducible quality based on feedback information obtained using laser imaging techniques. Two laser-based imaging techniques based on particle image velocimetry (PTV) and optical patternation map and contrast size and velocity distributions for indirect and direct pneumatic nebulizations in plasma spectrometry. Two pulses from thin laser sheet with known time difference illuminate droplets flow field. Charge coupled device (CCL)) captures scattering of laser light from droplets, providing two instantaneous particle images. Pointwise cross-correlation of corresponding images yields two-dimensional velocity map of aerosol velocity field. For droplet size distribution studies, solution is doped with fluorescent dye and both laser induced florescence (LIF) and Mie scattering images are captured simultaneously by two CCDs with the same field of view. Ratio of LIF/Mie images provides relative droplet size information, then scaled by point calibration method via phase Doppler particle analyzer.

Feedback mechanism for smart nozzles and nebulizers

An apparatus and method for providing direct liquid sample introduction using a nebulizer are provided. The apparatus and method include a short torch having an inner tube and an outer tube, and an elongated adapter having a cavity for receiving the nebulizer and positioning a nozzle tip of the nebulizer a predetermined distance from a tip of the outer tube of the short torch. The predetermined distance is preferably about 2-5 mm.

Short torch design for direct liquid sample introduction using conventional and micro-nebulizers for plasma spectrometry

A nebulizer adapted for adjusting a position of a capillary tube contained within the nebulizer is provided. The nebulizer includes an elongated tubular shell having a gas input port and a gas output port, a capillary adjustment adapter for displacing the capillary tube in a lateral direction via a rotational force, and a connector for connecting the elongated tubular shell, the capillary adjustment adapter and the capillary tube.

Demountable direct injection high efficiency nebulizer for inductively coupled plasma mass spectrometry

A simple, relatively low-cost direct injection high efficiency nebulizer (DIHEN) is suitable for argon inductively coupled plasma (Ar ICP) spectrometry. The DIHEN may be operated at solution uptake rates of 1-100 .mu.L/min. Analytical performance indices for the DIHEN and fundamental characteristics of the aerosol produced are obtained using an ICP mass spectrometer (ICPMS) and a 2-dimensional phase Doppler particle analyzer (2D PDPA), respectively. Results are compared to those obtained with a conventional crossflow pneumatic nebulizer (PN), equipped with a Scott-type spray chamber. Droplet sizes and velocities produced with the DIHEN are smaller than those reported for the direct injection nebulizer (DIN). The DIHEN offers optimal sensitivity at low injector gas flow rates (approx. 0.25 L/min) and high RF power (approx. 1.5 kW). For the 17 elements tested, detection limits (ppt) and sensitivities achieved with the DIHEN (at 85 .mu.L/min) are similar to or better than those obtained on the same instrument using the PN (at 1 mL/min). However, because the primary aerosol is injected directly into the plasma, oxide-to-metal ion ratios (MO.sup.+ /M.sup.+) are high as in the case of the DIN. The utility of the DIHEN for the analysis of small volume samples is demonstrated by microscale flow injection analysis (.mu.FIA) of Cr bound to human lung DNA. Detection of Cr at the femtogram level is feasible.

Direct injection high efficiency nebulizer for analytical spectrometry

An ultrasonic humidifier is converted to a low-cost, geyser-type ultrasonic nebulizer for atomic spectrometry. The device may be operated in either a batch or the continuous mode. Long-term precisions of 1-2% were achieved for 14 elements. For a sample uptake rate of 1 mL/min., detection limits measured with the geyser-type ultrasonic nebulizer were superior to those obtained with a PN by a factor of 8-50. While detection limits measured utilizing the converted nebulizer of the present invention were similar to those reported for commercial ultrasonic nebulizers, the converted nebulizer of the present invention is much less expensive.

Low-cost ultrasonic nebulizer for atomic spectrometry

An inductively coupled plasma torch including a base member, a plasma tube and a threaded insert member within the plasma tube for directing the plasma gas in a tangential flow pattern. The design of the torch eliminates the need for a separate coolant gas tube. The torch can be readily assembled and disassembled with a high degree of alignment accuracy.

Growing community of inventors

Potomac, MD, United States of America

Akbar Montaser