Helium conservation by discontinuous introduction in the flowing atmospheric-pressure afterglow source for ambient desorption-ionization mass spectrometry

Storey, Andrew P.; Zeiri, Offer; Ray, Steven J.; Hieftje, Gary M.

doi:10.1039/c5ja00228a

Cited by 6 publications

(4 citation statements)

References 24 publications

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“…The plasma continued to shrink in size until the Ar flow was restored (Figure b-4) and then gradually regained its brightness and diffuse appearance (Figure b-5) before it returned smoothly to its normal condition within ∼60 s following gas flow restoration (Figure b-6). This behavior is similar to the temporal progression of the discharge appearance in FAPA after interruption of He flow …”

Section: Resultssupporting

confidence: 72%

“…As argon diffuses from the APGD source and is replaced by air, the APGD plasma becomes less stable and eventually extinguishes if the Ar supply remains off. This phenomenon appears similar to a discontinuous helium flowing atmospheric-pressure afterglow (FAPA) desorption ion source, , which could be sustained for up to several minutes after the helium flow was halted. In our present study, we set T OFF to <1 s to avoid plasma extinction.…”

Section: Resultsmentioning

confidence: 78%

“…This behavior is similar to the temporal progression of the discharge appearance in FAPA after interruption of He flow. 33 Although detailed mechanistic study for signal enhancement is beyond the scope of the current work, two experiments were performed to narrow down the candidates. In general, common causes for signal enhancement in atomic emission source are a rise in excitation temperature, longer residence time for the analyte, and increased atomic number densities of the analyte.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Highly Sensitive Determination of Arsenic and Antimony Based on an Interrupted Gas Flow Atmospheric Pressure Glow Discharge Excitation Source

Yang

Chan

et al. 2018

Anal. Chem.

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A novel interrupted gas flow (IF) technique has been proposed for highly sensitive determination of ultratrace levels of arsenic and antimony in water samples by atmospheric pressure glow discharge (APGD) excitation source coupled with HCl-KBH4 hydride generation (HG). It is demonstrated that the gas flow interruption technique provides a dramatic and reproducible enhancement of emission signals of 1–2 orders of magnitude for As and Sb over conventional continuous gas flow (CF) in APGD. The enhanced analyte emission sensitivities in IF-APGD were investigated from the viewpoint of changes in plasma excitation temperature and analyte density. With eight As lines as the thermometric probe, no measurable change in excitation temperature was found, suggesting that the enhancement is caused by an increase in analyte number density in the plasma immediately following the gas flow interruption. Furthermore, the enhancement factor was found to increase with the time interval in between the gas interruption, supporting an analyte adsorption (or trap)-release mechanism hypothesis. Under optimized conditions, the detection limits (DLs) of IF-APGD mode for As and Sb were calculated to be 0.02 and 0.003 μg L–1, which are, respectively, about 27- and 120-fold improved compared to CF-APGD mode. The linearity of calibration for both As and Sb reached R 2 > 0.999 in the 0.1–5 μg L–1 range. The accuracy of the proposed method was validated by the determination of certified reference materials (CRMs), and the results agreed well with the certified values.

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Section: Resultssupporting

confidence: 72%

Section: Resultsmentioning

confidence: 78%

Section: ■ Results and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Highly Sensitive Determination of Arsenic and Antimony Based on an Interrupted Gas Flow Atmospheric Pressure Glow Discharge Excitation Source

Yang

Chan

et al. 2018

Anal. Chem.

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“…In this type of source a microplasma (which can be generated in a variety of ways) is directed at an angle to the sample such that the aerglow interacts with the surface of the sample to cause desorption, then ionisation of the desorbed molecules. Storey et al 56 investigated a owing atmospheric pressure aerglow (FAPA) source contained in a quartz tube (9 mm i.d., 12 mm o.d.) sealed around a concentric tungsten pin cathode and capillary anode (stainless steel, 2.5 cm long, 3.3 mm o.d., 1.5 mm i.d.).…”

Section: Instrumentationmentioning

confidence: 99%

Atomic spectrometry update: review of advances in atomic spectrometry and related techniques

Evans

Pisonero

Smith

et al. 2016

J. Anal. At. Spectrom.

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SUMMARY OF CONTENTS This review covers developments in 'Atomic Spectrometry'. It covers atomic emission, absorption, fluorescence and mass spectrometry, but excludes material on speciation and coupled techniques which is included in a separate review. It should be read in conjunctionwith the other related reviews in the series. [1][2][3][4][5][6] Sample introductionThis section covers developments in sample introduction for all instrumental methods. LiquidsLiquid sample introduction relates to methods wherein the sample is introduced into the instrument in the form of a liquid, such as through nebulization or into a thermal vaporizer; whereas in vapour generation the sample is initially in the form of a liquid but is converted to a vapour prior to introduction into the instrument. Sample pre-treatment.A general review of on-line preconcentration for ICP-MS has been published by Das et al. 7 , covering solid phase methods and including 63 references. Several reviews of sample pretreatment methods used for atomic spectrometry are worth noting because they focus on specific areas: Kocurova et al. 8and Jain and Verma 9 have reviewed advances in DLLME (53 references) and SDME (407 references) respectively; Zhao et al. the same authors studied the stability of the labelled complexes at different pH and temperature, and when subject to separation using LC. They reported a significant decrease in stability when LC separation was used, and some degradation at 37 °C compared to 2 °C.Li et al. An immunoassay-linked method using gold nano-particles has been developed by Jarujamrus et al. 33 . In this approach the monoclonal antibody-chloramphenicol was attached to a solid support. Antigen-chloramphenicol was labelled with gold nano-particles (10 nm) at pH 9.5, attached to a bovine serum albumin protein and mixed with unlabelled antigenchloramphenicol, which was then added to the antibody-chloramphenicol. for U and Th respectively in water samples.

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Use of Interrupted Helium Flow in the Analysis of Vapor Samples with Flowing Atmospheric-Pressure Afterglow-Mass Spectrometry

Storey

Zeiri

Ray

et al. 2016

J. Am. Soc. Mass Spectrom.

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The flowing atmospheric-pressure afterglow (FAPA) source was used for the mass-spectrometric analysis of vapor samples introduced between the source and mass spectrometer inlet. Through interrupted operation of the plasma-supporting helium flow, helium consumption is greatly reduced and dynamic gas behavior occurs that was characterized by schlieren imaging. Moreover, mass spectra acquired immediately after the onset of helium flow exhibit a signal spike before declining and ultimately reaching a steady level. This initial signal appears to be due to greater interaction of sample vapor with the afterglow of the source when helium flow resumes. In part, the initial spike in signal can be attributed to a pooling of analyte vapor in the absence of helium flow from the source. Time-resolved schlieren imaging of the helium flow during on and off cycles provided insight into gas-flow patterns between the FAPA source and the MS inlet that were correlated with mass-spectral data. Graphical Abstract ᅟ.

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Helium conservation by discontinuous introduction in the flowing atmospheric-pressure afterglow source for ambient desorption-ionization mass spectrometry

Cited by 6 publications

References 24 publications

Highly Sensitive Determination of Arsenic and Antimony Based on an Interrupted Gas Flow Atmospheric Pressure Glow Discharge Excitation Source

Highly Sensitive Determination of Arsenic and Antimony Based on an Interrupted Gas Flow Atmospheric Pressure Glow Discharge Excitation Source

Atomic spectrometry update: review of advances in atomic spectrometry and related techniques

Use of Interrupted Helium Flow in the Analysis of Vapor Samples with Flowing Atmospheric-Pressure Afterglow-Mass Spectrometry

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