Background spectral features in electrothermal vaporization inductively coupled plasma mass spectrometry: molecular ions resulting from the use of chemical modifiers

doi:10.1016/0584-8547(93)80123-C

Spectrochimica Acta Part B: Atomic Spectroscopy

Volume 48, Issue 11, September 1993, Pages 1347-1364

https://doi.org/10.1016/0584-8547(93)80123-C Get rights and content

Abstract

The formation of background polyatomic ions in electrothermal vaporization inductively coupled plasma mass spectrometry is reported. Vaporization temperatures ranging from 800 to 2500°C were studied. Carbon-containing polyatomic ions interfere with the determination of Mg, Si, Ti, Ca and Cr. Polyatomic ions resulting from the vaporization of ascorbic acid, sodium chloride, magnesium nitrate, nickel nitrate and palladium nitrate chemical modifiers were studied. Microgram quantities of chemical modifier resulted in oxide and argide polyatomic ion intensities equivalent to picogram background equivalent masses for interfered analyte isotopes. In most cases alternative analyte isotopes free of interference were available. The formation of carbide of nitride modifier molecular ions was not observed. The argon dimer could be used as a diagnostic tool to indicate plasma loading effects and matrix suppression effects resulting from the use of chemical modifiers.

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Electrothermal vaporization
2020, Sample Introduction Systems in ICPMS and ICPOES
This chapter reviews the development of electrothermal vaporization (ETV) as a sample introduction technique for inductively coupled plasma (ICP) optical emission spectrometry and mass spectrometry. This alternative sample introduction technique to the conventional nebulization system was developed and optimized over many years to the ETV system that is now commercially available. The advantages and disadvantages of using ETV as a sample introduction technique are discussed. The most important feature of interfacing ETV to the ICP is that samples can be directly introduced in various forms: as a solid, a liquid, or a mixture of the two, i.e. a slurry. It can thus eliminate the need for digestion, thereby completely avoiding the use of harsh concentrated acids and thus greatly simplifying sample preparation. This is invaluable for difficult to digest samples. It also only requires milligram quantities of solid for their direct analysis, which is invaluable in applications where the amount of sample is limited, such as in forensic analysis.
Carbon microparticles as a physical carrier for ETV-ICP-MS
2019, Talanta
Citation Excerpt :
Carbon particles produced from organic compounds during pyrolysis can serve as analyte condensation sites and then act as carriers, improving the analyte transport efficiency [8,9]. However, the disadvantage of using organic compounds as the modifier could be the increased formation of carbon-containing molecular ions that interfere with light elements such are Mg, Si, Ti, Ca and Cr [9]. Carbon particles can be also produced from gaseous organic compounds as CCl4 added to the sample gas flow [1,9].
In this study, carbon microparticles (CMs) as a physical carrier to enhance the analyte transport efficiency for inductively coupled plasma mass spectrometry connected with electrothermal vaporization (ETV-ICP-MS) are proposed. Carbon microparticles mixed with samples or calibration standard solutions were dosed as a slurry into the graphite furnace.
The optimization of working conditions was done for the standard solution 0.5 μg L⁻¹ of Au and Tl. The pyrolysis and vaporization temperatures were 500 and 2700 °C for Au and 400 and 1900 °C for Tl. The optimized CMs concentration was 1 g L⁻¹ for Au and 2.5 g L⁻¹ for Tl. For the quantification, external calibration standard solutions were used.
The result obtained for Au in the digested CRM GBW 07601 (the informatory value 2.1 ± 2 μg kg⁻¹) was 2.2 ± 0.1 μg kg⁻¹. The result for Tl in the digested CRM BCR 679 (the certified value 3 ± 0.3 μg kg⁻¹) was 3.2 ± 0.2 μg kg⁻¹ and in the slurry 2.7 ± 0.1 μg kg⁻¹. The result for Tl in the CRM GBW 10052 (the certified value 57 ± 11 μg kg⁻¹) was 51 ± 3 μg kg⁻¹. The instrumental limits of detection were 0.016 ng L⁻¹ for Au and 0.026 ng L⁻¹ for Tl. The recoveries and repeatabilities measured on calibration standards were in the range 99–100% and 0.2–2.3% for Au and 100–111% and 2.9–6.7% for Tl.
Determination of Cu, As, Hg and Pb in vegetable oils by electrothermal vaporization inductively coupled plasma mass spectrometry with palladium nanoparticles as modifier
2013, Talanta
The determination of Cu, As, Hg and Pb in vegetable oils by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) was investigated. The oils were injected in the form of emulsions containing 5% m/v vegetable oil, 1.5% v/v Triton X-100 and 50 μg mL⁻¹ ascorbic acid. Palladium nanoparticles (Pd-NPs) were used as modifier. The interference of ⁴⁰Ar³⁵Cl⁺ at arsenic mass m/z 75 was reduced significantly using dynamic reaction cell (DRC). Standard addition and isotope dilution methods were used for the quantifications. The method reported has been applied to the determination of Cu, As, Hg and Pb in selected vegetable oil samples purchased from a local market. The analytical results obtained were in good agreement with those of digested samples analyzed by pneumatic nebulization ICP-MS with 95% confidence according to Student t-test (except for Cu). Precision between sample replicates was better than 10% with the ETV-ICP-MS method. The detection limits obtained from standard addition curves were 0.4, 0.5, 1.1 and 0.4 ng g⁻¹ for Cu, As, Hg and Pb, respectively, in the original oil samples.
Electrothermal vaporization-inductively coupled plasma-mass spectrometry: A versatile tool for tackling challenging samples. A critical review
2009, Analytica Chimica Acta
Citation Excerpt :
This had a dramatic influence on the number of papers published on the topic in the following yeas, as can be seen in Fig. 1A. In 1992, the number of publications per year was doubled with respect to the papers published in 1991; and in 1994, the number of publications was five times higher (at that moment it was estimated that more than 100 commercial electrothermal vaporizers had been sold worldwide [8]). From this moment on, the rate of ETV–ICP-MS publications per year has only undergone few changes, with a limited but steady number of contributions in-between 20 and 30 per year.
In this review, the literature on the subject of electrothermal vaporization–inductively coupled plasma-mass spectrometry (ETV–ICP-MS) published during the last decade is reviewed with a double purpose: an evaluation of the possibilities of this technique for dealing with very challenging analytical applications on the one hand, and the establishment of a reference guide for method development in ETV–ICP-MS on the other. First, a brief introduction, pointing out the milestones in the development of the technique will provide the reader with a better understanding of the present situation of ETV–ICP-MS and its future perspective. After a section on the basic processes occurring in the furnace and during analyte transport, a guide for method development for challenging analytical applications is proposed, based on the existing literature. Next, the latest contributions in the main application areas of the field are reviewed, with special attention to the most challenging ones: i.e. speciation, “thermal” resolution, enabling complex matrixes to be analyzed and spectral overlap to be avoided, and the direct analysis of slurries and solid samples. Finally, the advantages obtained by coupling an ETV unit to newer types of ICP-MS instrumentation, equipped with collision/reaction cells, time-of-flight (TOF) or sector field (SF) spectrometers, are also discussed.
Optimization of a single-drop microextraction method for multielemental determination by electrothermal vaporization inductively coupled plasma mass spectrometry following in situ vapor generation
2009, Spectrochimica Acta - Part B Atomic Spectroscopy
A headspace single-drop microextraction (HS-SDME) method has been developed in combination with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the simultaneous determination of As, Sb, Bi, Pb, Sn and Hg in aqueous solutions. Vapor generation is carried out in a 40 mL volume closed-vial containing a solution with the target analytes in hydrochloric acid and potassium ferricyanide medium. Hydrides (As, Sb, Bi, Pb, Sn) and Hg vapor are trapped onto an aqueous single drop (3 µL volume) containing Pd(II), followed by the subsequent injection in the ETV. Experimental variables such as medium composition, sodium tetrahydroborate (III) volume and concentration, stirring rate, extraction time, sample volume, ascorbic acid concentration and palladium amount in the drop were fully optimized. The limits of detection (LOD) (3σ criterion) of the proposed method for As, Sb, Bi, Pb, Sn and Hg were 0.2, 0.04, 0.01, 0.07, 0.09 and 0.8 µg/L, respectively. Enrichment factors of 9, 85, 138, 130, 37 and 72 for As, Sb, Bi, Pb, Sn and Hg, respectively, were achieved in 210 s. The relative standard deviations (N = 5) ranged from 4 to 8%. The proposed HS-SDME-ETV-ICP-MS method has been applied for the determination of As, Sb, Bi, Pb, Sn and Hg in NWRI TM-28.3 certified reference material.
Slurry sampling electrothermal vaporization inductively coupled plasma mass spectrometry for the determination of As and Se in soil and sludge
2007, Analytica Chimica Acta
Citation Excerpt :
It is of interest to see the effect of the addition of other modifiers on the ion signals. Palladium has been used as chemical modifier to improve the signals of various elements in many ETV-ICP-MS applications [8,28,29]. Hence, in this study Pd was selected as co-modifier to improve the signals of As and Se.
Slurry sampling electrothermal vaporization (ETV) inductively coupled plasma mass spectrometry (ICP-MS) has been applied to determine As and Se in soil and sludge samples. The influences of instrument operating conditions and slurry preparation on the ion signals were reported. Pd and ascorbic acid were used as mixed modifiers to enhance the ion signals. The effectiveness of ETV sample introduction technique for alleviating various spectral interferences in ICP-MS analysis has been demonstrated. This method has been applied to determine As and Se in NIST SRM 2709 San Joaquin soil reference material and NIST SRM 2781 domestic sludge reference material and a farmland soil sample collected locally. Since the sensitivities of As and Se in slurry solution and aqueous solution were different, analyte addition technique was used to determine As and Se in these samples. The As and Se analysis results of the reference materials agreed with the certified values. The precision between sample replicates was better than 5% for all determinations. The method detection limit estimated from analyte addition curves was about 0.03 and 0.02 μg g⁻¹ for As and Se, respectively, in original soil and sludge samples.

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Background spectral features in electrothermal vaporization inductively coupled plasma mass spectrometry: molecular ions resulting from the use of chemical modifiers

Abstract

Spectrochim. Acta

Spectrochim. Acta

Spectrochim. Acta

Spectrochim. Acta

Spectrochim. Acta

Spectrochim. Acta Rev.