Water-Soluble and Total Sulfur in Particulate Matter Determined by Inductively Coupled Plasma Dynamic Reaction Cell Mass Spectrometry (ICP-DRC-MS)

Abstract

Environmental Context.Sulfate in particulate matter is usually collected by a high-volume air sampler and analysed as a soluble extract by ion chromatography. The use of an inductively coupled plasma mass spectrometer fitted with a dynamic reaction cell enables not only the water-soluble, but also the total sulfate to be determined at the same time as the analyses of metal ions. Results from Hong Kong show that sulfate is strongly correlated with crustal species in particulate matter. Abstract.An instrumental method has been developed for the determination of sulfur in particulate matter using inductively coupled plasma dynamic reaction cell mass spectrometry. The reaction gas O2 was employed to convert S+ into the diatomic species SO+, and analysed at two different mass-to-charge ratios. The limit of detection for the 32S16O+ determination is ~1 ng S m–3. The method has the advantages that not only soluble sulfur (as commonly analysed by ion chromatography) but also total sulfur can be determined on the same instrument as many metal species. The mean values (± standard deviations) for a spring sampling program of particulate matter of diameter less than 10 μm (PM10) in Hong Kong (n = 13) for soluble and total S were 5.2 ± 1.2 μg m–3 and 5.5 ± 1.3 μg m–3 respectively. These values are quite low owing to a predominantly easterly airstream. Sulfur in PM10 is strongly correlated with the crustal species Ca, Al and Mn.

Measurement of gold and sulfur mass fractions in l-cysteine-modified gold nanoparticles by ICP-DRC-MS after acid digestion: validation and uncertainty of results

“…However the use of isotopes also presents some problems, such as the mass discrimination correction for the accurate determination of isotope abundances or the use of very expensive enriched stable isotopes. 27 Hence external calibration without internal standard is often used to measure the concentration of S in DRC mode, [17][18][19] with a dynamic range of one order of magnitude and linear correlation coefficient of 0.997-0.999.…”

“…Parameter optimization to improve the detection limit for S Solutions of raw and cysteine-modified gold nanoparticles without centrifugal purification and acid digestion were diluted in 0.5% aqua regia to achieve about 20 mg L À1 of Au and, for the modified particles, 30 mg L À1 of S. They were used as blank (raw gold) and sample (modified gold) for the experiments to optimize the ratio of signal to background (S/B) for 32 S 16 O + by a Central Composite Inscribed Design 16 with ICP-MS parameters: radio frequency power (range: 1100-1300 W), cell gas flow (range: 0.2-0.8 mL min À1 ), and dynamic bandpass tuning parameter, Rpq (range: 0.3-0.5). [17][18][19] The design requires 15 experiments, and the centre point was replicated for calculating the standard deviation of an effect. Additionally another DRC parameter Rpa was independently investigated in the range from 0 to 0.05 by using a set of simulated blank (20 000 mg L À1 Au) and sample (20 000 mg L À1 Au + 100 mg L À1 S) solutions prepared from certified standards of Au and S in 1.2% aqua regia.…”

Online High Temporal Resolution Measurement of Atmospheric Sulfate and Sulfur Trioxide with a Light Emitting Diode and Liquid Core Waveguide-Based Sensor

“…The methods for monitoring atmospheric SO 3 and SO 4 2– can be classified into off-line and online modes. At present, the SO 4 2– in atmospheric aerosols are mainly off-line collected on a membranous collector, extracted, and then detected by ion chromatography, optical spectrometry, or mass spectrometry. − The storage and transfer efficiency are the primary technical difficulties for these off-line methods. Additionally, these methods cannot meet the demand for the continuous monitoring of atmospheric chemical composition information over a period of time. , As a result, methods that combine online collection and sulfate detection in atmospheric aerosols are required .…”

Oxygenation Mechanism of Ions in Dynamic Reaction Cell ICP-MS

“…[30][31][32] Oxygenation is an effective way of avoiding spectral interferences by producing an oxide ion free from interfering molecular ions or by oxygenating the isobaric interfering ions. [33][34][35][36][37][38][39][40][41][42][43] However, the effectiveness of O2 has not been evaluated sufficiently and the underlying mechanism of oxygenation in the reaction cell has not been fully elucidated, although the mechanisms underlying the use of NH3 and CH4 have been discussed by several researchers. We investigated the mechanism of oxygenation by using the bond energy and the enthalpy change (ΔH) between the ions and O, and demonstrated the usefulness of theoretical calculations for elucidating reaction mechanisms in DRCs.…”