Rapid Elemental Analysis of Aerosols Using Atmospheric Glow Discharge Optical Emission Spectroscopy

Abstract

A new, low-cost approach based on the application of atmospheric radio frequency glow discharge (rf-GD) optical emission spectroscopy (OES) has been developed for near real-time measurement of multielemental concentration in airborne particulate matter. This method involves deposition of aerosol particles on the tip of a grounded electrode of a coaxial microelectrode system, followed by ablation, atomization and excitation of the particulate matter using the rf-GD. The resulting atomic emissions were recorded using a spectrometer for elemental identification and quantification. The glow discharge plasma was characterized by measuring spatially resolved gas temperatures (378 – 1438 K) and electron densities (2 – 5 × 1014 cm−3). Spatial analysis of the spectral features showed that the excitation of the analyte occurred in the region near the collection electrode. The temporal analysis of spectral features in the rf-GD showed that the collected particles were continuously ablated; the time for complete ablation of 193 ng of sucrose particles was found to be approximately 2 s. The system was calibrated using 100 nm particles containing C, Cd, Mn, and Na, respectively. Our method provides limits of detection in the range of 0.055 – 1.0 ng, and a measurement reproducibility of 5 – 28%. This study demonstrates that the rf-GD can be an excellent excitation source for the development of low-cost hand-held sensors for elemental measurement of aerosols.

Sensitive and Environmentally Friendly Field Analysis of Waterborne Arsenic by Electrochemical Hydride Generation Microplasma Optical Emission Spectrometry

“…However, bulky, expensive, and energy-consuming instruments are usually required, making them unsuitable for field analysis and unaffordable for low-income countries. Recently, several compact and low-power consuming microplasmas were successfully used to develop inexpensive and robust miniaturized atomic spectrometers, including miniaturized inductively coupled plasma (ICP), microwave-induced plasma (MIP), capacitively coupled plasma (CCP), dielectric barrier discharge (DBD), − atmospheric-pressure glow discharge (APGD), − and point discharge (μPD). − Despite increased interest in microplasma atomic spectrometry, their sensitivities are mostly too low to meet the demands from the field analysis of waterborne arsenic. In contrast to other sampling techniques, chemical vapor generation (CVG) usually converts nonvolatile analytes to their volatile species and separates them from condensed liquid phase, yielding the advantages of high sample introduction efficiency and efficient matrix separation.…”

Real-Time Measurement of Airborne Carbon Nanotubes in Workplace Atmospheres

“…Figure c shows the cross-sectional view of the CAM used in our study. The design and collection characteristics of the CAM used by our group have been described in detail elsewhere. ,− The collection efficiency of the CAM was approximately 65% (Figure S1). The CAM uses two coaxial tungsten electrodes with a separation distance of 3 mm.…”

Atomic Spectrometry Update – a review of advances in environmental analysis

“…Recent work was summarised in the following three papers. In a procedure involving a prototype rf-GD-AES instrument, aerosols were preconcentrated 29 on a microelectrode tip. The achievable LOD was in the range 0.05 to 1 ng with a reproducibility of 5-28% when tested with 100 nmsized particles containing C, Cd, Mn and Na.…”