A Field-Portable Plasma Source Monitor for Real-Time Air Particulate Monitoring

Abstract

In this research, a novel portable instrument for on-site, real-time air particulate monitoring was developed. It is highly desirable to use microwave plasmas for on-site, real-time environmental and occupational hazard monitoring because they can be sustained with various gases at relatively low power and possess excellent detection capabilities for both metal and nonmetal air pollutants. In the new instrument design, a microwave plasma was selected as an excitation source and was used in conjunction with atomic emission spectrometry. A small, integrated spectrometer with a charge-coupled detector (CCD) was used for optical signal detection. An efficient, in situ air-sampling system was developed for direct sampling of air particles into the plasma. Characterization and calibration of the new instrument were achieved with an in-house-fabricated high-efficiency nebulization-desolvation system. Tolerance of the microwave argon plasma source to air introduction was tested, and the operational parameters were optimized. Analytical performance and the feasibility of the newly developed portable instrument for aerosol particle analysis were evaluated. Some advantages and possible applications of the new instrument are discussed. The instrument provides an innovative tool for rapid environmental and occupational hazard monitoring.

New Approach for Near-Real-Time Measurement of Elemental Composition of Aerosol Using Laser-Induced Breakdown Spectroscopy

“…Other substrate methods that use focused collection with an aerodynamic lens could perhaps achieve detection limits comparable to our system (Park et al 2009); however, the method requires use of large vacuum pumps, lower sampling flow rates, and only allows analysis of a limited particle size range. It is also worth noting that the detection limits of our system are an order of magnitude better than those of the microwave-induced plasma spectroscopy system of Duan et al (2000).…”

Trace-level beryllium analysis in the laboratory and in the field: state of the art, challenges and opportunities

“…At this symposium, papers were presented on techniques utilizing LIBS, MIPS, TOFMS, voltammetry 60,61 and colorimetric surface wipes 62 . The LIBS, MIPS, and colorimetric techniques are now commercially 395 available 42,44,63 , along with the atomic fluorescence technique developed more recently [28][29][30] . In 2002-03, a group of scientists from DOE, NIOSH, and the U. S. Department of Defense (DOD) developed preliminary criteria for real-time air monitoring equipment 400 and surface wipe analyzers 59,64 .…”

“…These techniques also avoid the sample preparation requirements and associated liquid waste generation of more traditional analytical 280 techniques, and could potentially be made field-portable. These techniques include laser induced breakdown spectroscopy (LIBS) 42 , microwave induced plasmas spectroscopy (MIPS) 43,44 , aerosol time of flight mass spectroscopy (TOFMS) 45 , and surface enhanced Raman 285 spectroscopy (SERS) 46 . Although there is substantial interest in these techniques, none of them has as yet gained wide acceptance for several reasons.…”

Mapping the ion kinetic energy in a helium microwave plasma orthogonal acceleration time‐of‐flight mass spectrometer

“…4 The microwave plasma ion source employs a commercial 2450 MHz microwave power generator (Model GMP-03K/SM, Sairem S.A., France) and a modified version microwave plasma torch. 12,13 The plasma torch and its housing were installed on an X -Y -Z stage and coupled to a TOF-MS instrument (Model Angular reflectron D-850, R. M. Jordan Co., Grass Valley, CA). A peristaltic pump (Minipuls 3, Gilson Medical Electronics Inc., WI) was used to deliver the sample solution to an ultrasonic nebulizer (U-5000 AT, CETAC Technologies Inc., NE).…”