Approaching Standardless Quantitative Elemental Analysis of Solids: Microsecond Pulsed Glow Discharge and Buffer-Gas-Assisted Laser Ionization Time-of-Flight Mass Spectrometry

Abstract

Among various ionization sources for mass spectrometry, microsecond pulsed glow discharge (MP-GD) and buffer-gas-assisted laser ionization (BGA-LI) sources have the potential for direct quantitative elemental analysis of solids without the requirement of standard reference materials. The analytical potential of these two ionization sources has been evaluated by coupling them to orthogonal time-of-flight mass spectrometry (MS). A straightforward method was proposed to achieve the quantitative result: if a spectrum contains little interference and elemental peak currents are proportional to their concentrations, then the molar concentration of each element is equal to its ion current proportion in the total ion current. Two series of metal standards were applied for the evaluation. Explicit spectra with little interference can be acquired by both techniques. The interferences contribute only a very small portion to the total ion current for MP-GD-MS and BGA-LI-MS; therefore, their influence on the quantitative result can be ignored. All metal elements can be determined quite accurately by the proposed quantitation method, while gaps exist for nonmetal elements due to the high ionization potentials or gas species interference. Between the two techniques, BGA-LI-MS offers a more accurate quantitative result, primarily due to its higher plasma temperature.

Quantitative imaging of fluorine in human teeth by cryogenic laser ionization time-of-flight mass spectrometry

“…28 For LIMS with less interference and element intensities proportional to their concentrations, the element concentration can be calculated by dividing its ion current by the total ion current, resulting in a direct quantication method. 25,29 Therefore, this study aims to develop a novel F quantitative imaging technique and investigate the distribution of F in teeth, thus further extending the technique to cariesrelated research.…”

Measuring Pb, Th, and U inter-element ratios in geological materials using extreme ultraviolet laser ablation and ionization mass spectrometry

“…Reducing the effects of sample chemistry in laser-based mass spectrometry methods has been achieved by optimizing the laser's pulse duration and wavelength (amongst other system modications [30][31][32] ). For example, using ultraviolet/ visible/infrared (UV/Vis/IR) wavelength lasers with pulse durations of femtoseconds (fs) over typical nanosecond (ns) pulses has resulted in the reduction of thermal effects from ablation.…”

Larmor Precession: Observation and Utilization for Boosting the Signal Intensity of Radio Frequency Glow Discharge Mass Spectrometry

“…[3][4][5][6][7] The ability to analyze solids directly, and the ease of preparation, low detection limit (down to ng•g −1 ) and minimal matrix effects have made GD-MS useful for accurate determination of trace and ultra-trace elements in solid materials. [8][9][10][11][12] Although GD-MS has been widely used in advanced materials, geology, environmental science, and other fields, it usually requires conducting material to support the discharge of the insulators because of poor sample conductivity. [13][14][15][16][17][18] The introduction of a radio-frequency (rf) source into GD-MS allows direct analysis of conductive and non-conductive samples, either bulk solids or layered materials.…”

“…Rapid development of new inorganic materials and the effect of trace elements on material properties has increased the need for more facile and efficient techniques for characterization. , Glow discharge mass spectrometry (GD-MS) is often the best choice for direct analysis of solid materials because it generates a stable analyte ion population directly and avoids the problems of dissolution, dilution, and contamination that may arise from techniques requiring solution samples. − The ability to analyze solids directly and the ease of preparation, low detection limit (down to ng·g –1 ), and minimal matrix effects have made GD-MS useful for accurate determination of trace and ultratrace elements in solid materials. − …”