Array Point Discharge as Enhanced Tandem Excitation Source for Miniaturized Optical Emission Spectrometer

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Plasma Physics

Background:

• Miniaturized optical emission spectrometers require efficient excitation sources for improved detectability.
• Traditional microplasma sources can have limitations in excitation capability and analyte interception.
• Coupling sample introduction devices like hydride generation (HG) is crucial for effective elemental analysis.

Purpose of the Study:

• To design and construct a compact tandem excitation source using array point discharge (ArrPD) microplasma.
• To develop a miniaturized optical emission spectrometer coupled with a hydride generation unit.
• To investigate the excitation and enhancement processes within the ArrPD microplasma.

Main Methods:

• Arrangement of three pairs of point discharges in sequence within a narrow discharge chamber to create ArrPD microplasma.
• Development of a new instrument for simultaneous detection of atomic emission and absorption spectral responses.
• Optimization of experimental conditions for elemental detection.

Main Results:

• Achieved low limits of detection (LODs) for As, Ge, Hg, Pb, Sb, Se, and Sn (e.g., 0.05 μg L⁻¹ for Hg).
• Obtained relative standard deviations (RSDs) below 4% for all analyzed elements.
• Demonstrated 3-6 fold improvement in analytical sensitivities compared to single point discharge microplasma sources.
• Successfully analyzed Certified Reference Materials (CRMs).

Conclusions:

• The developed ArrPD microplasma source significantly enhances excitation efficiency and OES signal.
• The miniaturized spectrometer offers high detectability, low power consumption, compactness, and portability.
• This system shows great potential for elemental analytical chemistry applications.