Coupled Plasma Tandem Mass Spectrometry Research Articles

Rapid determination of toxic and essential metal binding proteins in biological samples by size exclusion chromatography-inductively coupled plasma tandem mass spectrometry

Metalloproteins binding with trace elements play a crucial role in biological processes and on the contrary, those binding with exogenous heavy metals have adverse effects. However, the methods for rapid, high sensitivity and simultaneous analysis of these metalloproteins are still lacking. In this study, a fast method for simultaneously determination of both essential and toxic metal-containing proteins was developed by coupling size exclusion chromatography (SEC) with inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). After optimization of the separation and detection conditions, seven metalloproteins with different molecular weight (from 16.0 to 443.0 kDa) were successfully separated within 10 min and the proteins containing iron (Fe), copper (Cu), zinc (Zn), iodine (I) and lead (Pb) elements could be simultaneously detected with the use of oxygen as the collision gas in ICP-MS/MS. Accordingly, the linear relationship between log molecular weight and retention time was established to estimate the molecular weight of unknown proteins. Thus, the trace metal and toxic metal containing proteins could be detected in a single run with high sensitivity (detection limits in the range of 0.0020–2.5 μg/mL) and good repeatability (relative standard deviations lower than 4.5 %). This method was then successfully used to analyze metal (e.g., Pb, Zn, Cu and Fe) binding proteins in the blood of Pb-intoxicated patients, and the results showed a negative correlation between the contents of zinc and lead binding proteins, which was identified to contain hemoglobin subunit. In summary, this work provided a rapid and sensitive tool for screening metal containing proteins in large number of biological samples.

Subzero project: comparing trace element profiles of enriched mitochondria fractions from frozen and fresh liver tissue

From organs to subcellular organelles, trace element (TE) homeostasis is fundamental for many physiological processes. While often overlooked in early stages, manifested TE disbalance can have severe health consequences, particularly in the context of aging or pathological conditions. Monitoring TE concentrations at the mitochondrial level could identify organelle-specific imbalances, contributing to targeted diagnostics and a healthier aging process. However, mitochondria isolation from frozen tissue is challenging, as it poses the risk of TE losses from the organelles due to cryodamage, but would significantly ease routine laboratory work. To address this, a novel method to isolate an enriched mitochondria fraction (EMF) from frozen tissue was adapted from already established protocols. Validation of manganese (Mn), iron (Fe), and copper (Cu) quantification via inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) showed sufficiently low quantification limits for EMF TE analysis. Successful mitochondrial enrichment from frozen liver samples was confirmed via immunoblots and transmission electron microscopy (TEM) revealed sufficient structural integrity of the EMFs. No significant differences in EMF TEs between frozen and fresh tissue were evident for Mn and Cu and only slight decreases in EMF Fe. Consequently, EMF TEs were highly comparable for isolates from both tissue states. In application, this method effectively detected dietary differences in EMF Fe of a murine feeding study and identified the disease status in a Wilson disease rat model based on drastically increased EMF Cu. In summary, the present method is suitable for future applications, facilitating sample storage and high-throughput analyses of mitochondrial TEs.Graphical abstract

Green and blue infrastructure as model system for emissions of technology-critical elements

Over the recent decades, technological advancements have led to a rise in the use of so-called technology-critical elements (TCEs). Environmental monitoring of TCEs forms the base to assess whether this leads to increased anthropogenic release and to public health implications. This study employs an exploratory approach to investigate the distribution of the TCEs Li, Be, V, Ga, Ge, Nb, Sb, Te, Ta, Tl, Bi and the REYs (rare-earth elements including yttrium) in urban aerosol in the city of Vienna, Austria.Leaf samples (n = 292) from 8 plant species and two green facades and water samples (n = 18) from the Wienfluss river were examined using inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). Surface dust contributions were assessed by washing one replicate of each leaf sample and analysing the washing water (n = 146). The impacts of sampling month, plant species and storey level on elemental distribution were assessed by statistical tools and generative deep neural network modelling. Higher TCE levels, including Li, V, Ga, Ge, Tl, Bi, and the REYs, were found in the winter months, likely due to the use of de-icing materials and fossil fuel combustion. A. millefolium and S. heufleriana displayed the highest levels of Li and Ge, respectively. In addition, increased elemental accumulation at lower storeys was observed, including Be, Sb, Bi and the REYs, indicating greater atmospheric dust deposition and recirculation closer to ground level.The results suggest a broad association of TCE levels with urban dust. This study enhances the current understanding of TCE distribution in urban settings and underscores the importance of their inclusion in pollution monitoring. It highlights the complex interplay of human activities, urban infrastructure, and environmental factors, offering valuable insights for managing urban environmental health risks and underlining the need for comprehensive urban ecosystem studies.

Accurate Determination Of Selenium In The Serum By Inductively Coupled Plasma Tandem-Mass Spectrometry

Accurate Determination Of Selenium In The Serum By Inductively Coupled Plasma Tandem-Mass Spectrometry

Assessing Gas-Phase Ion Reactivity of 50 Elements with NO and the Direct Application for 239Pu in Complex Matrices Using ICP-MS/MS.

Understanding the reactivity of metal cations with various reaction gases in inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) is important to determine the best gas to use for a given analyte/interference pair. In this study, nitric oxide (NO) was investigated as the reaction gas following previous experimental designs. The reactions with 50 elements were investigated to examine periodic trends in reactivity, validate theoretical modeling of reaction enthalpies as a method to screen reactant gases, and provide a baseline data set for potential in-line gas separation methods. ICP-MS/MS studies involving actinides are typically limited to Th, U, and Pu, with analyses of Np and Am rarely reported in the literature. To date, only two previous methods have investigated the use of NO in ICP-MS/MS analyses. To showcase the utility of NO, a method was developed to measure 239Pu in the presence of environmental matrix constituent and other actinides, like what could be expected from postdetonation debris, with no chemical separation prior to analysis. 239Pu+ was reacted to form 239Pu16O+, eliminating interferences derived from the sample matrix by measuring the 239Pu+ intensity at m/z = 255 (239Pu16O+). To validate NO for 238U1H+ interference removal in environmental matrices, standard reference materials were diluted to 1 mg/g of solution and spiked to 0.05 pg/g of 239Pu and 1 μg/g 238U (Pu/U = 5 × 10-8). Measured 239Pu concentrations were within 6% of the spiked value. These results demonstrate that reliable 239Pu measurements can be made at levels relevant to nuclear forensics without the need for extensive chemical matrix separation prior to analysis.

Toward the boosted loading of cisplatin drug into liposome nanocarriers

Current challenges in oncology are largely associated with the need to improve the effectiveness of cancer treatment and to reduce drug’s side effects. An effective strategy to cope with these challenges is behind designing and developing drug delivery systems based on smart nanomaterials and approved anticancer drugs. The present study offers a novel and straightforward approach to efficiently load the cisplatin drug into the newly constructed liposome-based nanosystems as well a reliable technique for monitoring this process based on capillary electrophoresis hyphenated with inductively coupled plasma tandem mass spectrometry. The proposed drug-loading methodology comprises liposome formation via a simple ethanol-injection method and propels increased drug encapsulation using tailor-made freeze-thawing or lyophilization-hydration procedures. To optimize liposome generation and drug encapsulation, the effects of dilution medium and liposome composition (types of phospholipids and their percentage ratio) have been investigated in detail. It was shown that modest alterations of the composition of three-component phospholipid liposomes and parameters of the freeze-thawing procedure have a strong impact on the formation of cisplatin–liposome systems. The obtained cisplatin–liposome formulation features a remarkable degree of drug encapsulation, over 100 mg L–1, and holds promise for further preclinical development as a potent drug-delivery platform.

Novel method for chlorine determination in biofuel lipid feedstock by coupling a total sample introduction system (hTISIS) to an inductively coupled plasma tandem mass spectrometry (ICP-MS/MS)

BackgroundChlorine concentrations above 1 mg kg−1 in lipid feedstocks for biofuel production can generate corrosion issues in the different refining units as well as catalyst deactivation by clogging or fouling. To reach accurate analyses by inductively coupled plasma (ICP) techniques at low concentration levels, dilution in organic solvents rises as a simpler and more straightforward sample preparation methodology than conventional sample decomposition procedures (e.g., microwave-assisted acid digestion). However, matrix effects and the impact of the Cl chemical form on the signal must be overcome to obtain accurate results. ResultsIn this work, the high temperature torch integrated sample introduction system (hTISIS) operated at 350 °C is coupled to an inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) for the determination of Cl in lipid biofuel feedstock samples diluted in xylene and these results are compared with those reported by a conventional sample introduction system. Under optimal conditions of the hTISIS-ICP-MS/MS configuration, matrix effects are efficiently overcome (recovery values ranged from 101 to 104%) as well as the effect of the Cl chemical form on the signal for 6 organochloride compounds. Thus, an external calibration approach can be set to carry out the quantification of this element in real samples. The method is successfully validated, obtaining a good agreement in the Cl concentration reported in a standard reference material (SRM NIST 1634c) and also by comparing the concentration results obtained by external calibration and standard addition approaches in two biofuel feedstock samples. Significance and noveltyThe hTISIS coupled to an ICP-MS/MS system is used for the first time to overcome not only matrix effects but also the impact of the Cl chemical form in biofuel feedstock samples. This novel method, with a limit of quantification (LOQ) of 7.1 μg kg−1, give access to an accurate Cl determination in all kind of lipid feedstocks for clean fuel production.

Calibration methods for laser ablation Rb–Sr geochronology: comparisons and recommendation based on NIST glass and natural reference materials

Abstract. In situ rubidium–strontium (Rb–Sr) geochronology, using laser ablation–inductively coupled plasma–tandem mass spectrometry (LA-ICP-MS/MS) technology, allows rapid dating of K-rich minerals such as micas (e.g. biotite, muscovite, and phlogopite) and K-feldspar (potassium-containing feldspar). While many studies have demonstrated the ability of the method, analytical protocols vary significantly, and to date, no studies have provided an in-depth comparison and synthesis in terms of precision and accuracy. Here we compare four calibration protocols based on commonly used reference materials (RMs) for Rb–Sr dating. We demonstrate that downhole fractionation trends (DHFs) for natural biotite, K-feldspar, and phlogopite contrast with that for the commonly used Mica-Mg nano powder reference material. Consequently, Rb–Sr dates calibrated to Mica-Mg can be up to 5 % inaccurate, and the degree of inaccuracy appears to be unsystematic between analytical sessions. Calibrating to Mica-Mg also introduces excess uncertainty that can be avoided with a more consistent primary calibration material. We propose a calibration approach involving (1) NIST-610 glass as the primary reference material (PRM) for normalisation and drift correction and (2) a natural mineral with similar DHF characteristics to the analysed samples as matrix correction RM (MCRM) to correct the Rb/Sr ratio for matrix-induced offsets. In this work, MDC phlogopite (the source mineral for Mica-Mg nano powder) was used as the MCRM, consistently producing accurate Rb–Sr dates for a series of natural biotites and K-feldspars with well-characterised expected ages. Biotite from the Banalasta Adamellite, Taratap Granodiorite, and Entire Creek pegmatite are also suitable RMs for Rb/Sr ratio calibration purposes, with consistently <1.5 % fully propagated uncertainties in our methodological approach. Until calibration using isochronous natural standards as the primary RM becomes possible in data reduction software, the two-step calibration approach described here is recommended.

Validation of Mitra® VAMS® as a blood collection technique for trace elements analysis using ICP-MS/MS.

Background: Clinical dosage of toxic and essential elements in blood is well established and the collection method is still by venipuncture. This method has drawbacks and is not suited for everyone. Volumetric absorptive microsampling (VAMS) has beenshown to haveadvantages over venipuncture. Materials & methods: Usinginductively coupled plasma tandem mass spectrometry, a method for quantifying elements in whole blood sampled on VAMS was developed/validated. Method's performance was assessed by comparison with whole blood results. Results: Validation and performance assessment tests tend to show that most of the targeted elements provides accurate and reproducible results comparing to a method of reference. Conclusion: Overall, VAMS presents good preliminary results to eventually become an alternative to venipuncture for blood sampling for some trace elements analysis purposes.

F-Block reactions of metal cations with carbon dioxide studied by inductively coupled plasma tandem mass spectrometry.

f-Block chemistry offers an opportunity to test current knowledge of chemical reactivity. The energy dependence of lanthanide cation (Ln+ = Ce+, Pr+, Nd+-Eu+) and actinide cation (An+ = Th+, U+-Am+) oxidation reactions by CO2, was observed by inductively coupled plasma tandem mass spectrometry. This reaction is commonly spin-unallowed because the neutral reactant (CO2, 1Σ+g) and product (CO, 1Σ+) require the metal and metal oxide cations to have the same spin state. Correlation of the promotion energy (Ep) to the first state with two free d-electrons with the reaction efficiency indicates that spin conservation is not a primary factor in the reaction rate. The Ep likely influences the reaction rate by partially setting the crossing between the ground and reactive states. Comparison of Ln+ and An+ congener reactivity indicates that the 5f-orbitals play a small role in the An+ reactions.

Determination of technology-critical elements in seafood reference materials by inductively coupled plasma-tandem mass spectrometry

The certified reference materials (CRMs) BCR-668 (mussel tissue), NCS ZC73034 (prawn), NIST SRM 1566a (oyster tissue) and NIST SRM 2976 (mussel tissue) were analyzed for their mass fractions of 23 elements using inductively coupled plasma tandem-mass spectrometry (ICP-MS/MS). This study focused on the quantification of selected technology-critical elements (TCEs), specifically rare earth elements (REE) and the less studied TCEs Ga, Ge, Nb, In and Ta. Microwave assisted closed vessel digestion using an acid mixture of HNO3, HCl and H2O2 was applied to varying sample masses and two different microwave systems. Recoveries of 76% (Gd, NCS ZC73034) to 129% (Lu, BCR-668) were obtained for the REE and 83% (Ge, NCS ZC73034) to 127% (Nb, NCS ZC73034) for the less studied TCEs across all analyzed CRMs (compared to certified values) using the best-performing parameters. Mass fractions for all analyzed, non-certified elements are suggested and given with a combined uncertainty U (k = 2), including mass fractions for Ga (11 µg kg-1 ± 9 µg kg-1 to 67 µg kg-1 ± 8 µg kg-1) and In (0.4 µg kg-1 ± 0.3 µg kg-1 to 0.8 µg kg-1 ± 0.7 µg kg-1). This study provides mass fractions of possible new emerging contaminants and addresses the relevant challenges in quantification of less studied TCEs, thus allowing the application of existing CRMs for method validation in studies dealing with the determination of TCEs in seafood or other biota.Graphical abstract

Development of a Method for the Determination of Total Selenium in Soil, Maize Plants, and Maize Flour by Inductively Coupled Plasma Tandem Mass Spectrometry (ICP-MS/MS)

Selenium (Se) is a micronutrient that has multiple biochemical effects ranging from a nutritional deficiency at low levels to toxicity at high levels. Its quantification in environmental systems is vital to protect the health of people and animals. This study developed and validated methods to determine the total selenium (Se) concentration in soil, maize plants, and maize flour. The performance of the methods was ascertained using matrix certified reference materials (CRMs), namely NMIJ CRM 7303-a (trace elements in lake sediments), NIST SRM 1646-a (estuarine sediments), NIST SRM 1570-a (spinach leaves), NIST SRM 1571 (orchard leaves), NCS ZC 73010 (maize flour) and NIST RM 8437 (hard red spring wheat flour). All methods fulfilled the performance requirements of the AOAC International. An acceptable accuracy was achieved with percentage recoveries between 57 and 102% and E n ‐ scores within ±1 limits. Repeatability ( RSD r , % ) and intermediate precision ( RSD R , % ) ranged from 4 to 12%, and 9 to 15%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for soil were 0.024 ng. g−1 and 0.082 ng. g−1, respectively. The LODs and LOQs for maize plants and flour were 0.0036 and 0.0179 ng. g−1, respectively. The performance characteristics of the methods were comparable with previously reported methods, confirming reliability. The measurement uncertainty was evaluated following the guide to the expression of uncertainty in measurement (GUM). Relative expanded uncertainty at a 95% level of confidence ( k = 2 ) was less than 24% for the final measurement results for all the different matrices.

Photothermal nanofibers enable macromolecule delivery in unstimulated human T cells

Cell therapies such as adoptive T cell transfer require ex vivo modification of cells with exogenous cargo to modulate their phenotype (e.g., to express a synthetic antigen receptor) for optimal therapeutic efficacy upon reinfusion in a patient. Several studies have shown superior anti-tumor activity of minimally differentiated T cell subsets over their activated counterparts. Therefore, developing techniques for safe and efficient manipulation of these quiescent cells is important for both clinical applications and fundamental studies of T cell biology. Photoporation with photothermal electrospun nanofibers (PEN) is an efficient and minimally perturbing non-viral intracellular delivery technique for activated and expanded T cells. However, the technique has not yet been applied to unstimulated T cells. Here, we investigated the potential of PEN photoporation for delivery of macromolecules into these cells. First, we confirmed with inductively coupled plasma tandem mass spectrometry that there was no significant iron release from fibers after laser activation of PEN substrates for laser fluences up to 0.36 J/cm². Next, we demonstrated successful intracellular delivery of 150 kDa FITC-dextran as model macromolecule in resting and pre-activated lymphocytes with 55–60 % delivery efficiency. By analyzing metabolic activity, activation surface marker presentation and extracellular cytokine release, we found that PEN treatment had no effect on cell proliferation and limited impact on T cell activation propensity for all tested irradiation energies. Thus, our findings show that PEN photoporation holds promise as a safe and efficient delivery strategy, paving the way for its use in genetic modification of minimally differentiated T cells.

Trace-element analysis and radiometric dating by inductively coupled plasma–tandem mass spectrometry: Approaches and applications to metallogeny

Inductively coupled plasma–tandem mass spectrometry (ICP–MS/MS) has rapidly established itself as a method for interference-free trace-element and isotope ratio analyses and has broad applications in geochemistry and geochronology, which are essential for understanding ore formation processes and the source of fluids and metals. Connect ICP–MS/MS to a laser ablation (LA) system, in situ interference-free trace-element data from ore and gangue minerals can be obtained, providing an effective vector approach to mineral exploration. LA–ICP–MS/MS also provides an unprecedented method for in situ dating of β-decay radiogenic isotope systems, which have isobaric interferences between daughter and parent isotopes that mean their ratios cannot be measured using a single quadrupole ICP–MS. In this review, we elucidate the main differences between single quadrupole ICP–MS and ICP–MS/MS, and describe the different approaches (on-mass and mass-shift) that allow interference-free analyses. We review advances in ICP–MS/MS methodology for trace-element (mainly REEs, noble metals and halogens) analyses and laser-based in situ U–Pb (with 204Pb correction), 87Rb–87Sr, 176Lu–176Hf, and 187Re–187Os dating of minerals based on publications from January 2012 to July 2023. We also speculate on future applications of the LA–ICP–MS/MS technique in metallogeny.

A field‐based evaluation of portable XRF to screen for toxic metals in seafood products

AbstractPortable X‐Ray Fluorescence (XRF) has become increasingly popular where traditional laboratory methods are either impractical, time consuming, and/or too costly. While the Limit of Detection (LOD) is generally poorer for XRF compared to laboratory‐based methods, recent advances have improved XRF LODs and increased its potential for field‐based studies. Portable XRF can be used to screen food products for toxic elements such as lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As), manganese, (Mn), zinc (Zn), and strontium (Sr). In this study, 23 seafood samples were analyzed using portable XRF in a home setting. After XRF measurements were completed in each home, the same samples were transferred to the laboratory for re‐analysis using microwave‐assisted digestion and Inductively Coupled Plasma Tandem Mass Spectrometry (ICP‐MS/MS). Four elements (Mn, Sr, As, and Zn) were quantifiable by XRF in most samples, and those results were compared to those obtained by ICP‐MS/MS. Agreement was judged reasonable for Mn, Sr, and As, but not for Zn. Discrepancies could be due to (1) the limited time available to prepare field samples for XRF, (2) the heterogeneous nature of “real samples” analyzed by XRF, and (3) the small beam spot size (~1 mm) of the XRF analyzer. Portable XRF is a cost‐effective screening tool for public health investigations involving exposure to toxic metals. It is important for practitioners untrained in XRF spectrometry to (1) recognize the limitations of portable instrumentation, (2) include validation data for each specific analyte(s) measured, and (3) ensure personnel have some training in sample preparation techniques for field‐based XRF analyses.

Single-Particle ICP-MS/MS Application for Routine Screening of Nanoparticles Present in Powder-Based Facial Cosmetics.

The short- and long-term impacts of nanoparticles (NPs) in consumer products are not fully understood. Current European Union (EU) regulations enforce transparency on products containing NPs in cosmetic formulations; however, those set by the U.S. Food and Drug Administration are lacking. This study demonstrates the potential of single-particle inductively coupled plasma tandem mass spectrometry (spICP-MS/MS) as a screening method for NPs present in powder-based facial cosmetics (herein referred to as FCs). A proposed spICP-MS/MS method is presented along with recommended criteria to confirm particle presence and particle detection thresholds in seven FCs. FC products of varying colors, market values, and applications were analyzed for the presence of Bi, Cr, Mg, Mn, Pb, Sn, Ag, Al, and Zn NPs based on their ingredient lists as well as those commonly used in cosmetic formulations. The presence of NPs smaller than 100 nm was observed in all FC samples, and no correlations with their presence and market value were observed. Here, we report qualitative and semi-quantitative results for seven FC samples ranging in color, brand, and shimmer.

Multielement analysis of single red blood cells by single cell - inductively coupled plasma tandem mass spectrometry

A method for the analysis of essential metals (Fe, Cu, Mg, and Zn) and non-metals (P, S) in single red blood cells was developed by single cell (SC)-ICP-MS. The use of a triple quadrupole configuration (MS/MS) enabled an effective elimination of polyatomic interferences, which affect the accuracy of ICP-MS analysis using a single quadrupole mass analyzer. Fixation with glutaraldehyde for at least 90 days was developed to improve the quantification of elements in a single red blood cell. The experimental conditions were optimized while special attention was paid to the residence time of analytes in the plasma. Addition of a surfactant (0.05% (v/v) Tween80®) improved quantification of elements in fixed red blood cells. The detection limits obtained by SC-ICP-MS/MS were lower than for ICP-MS, especially for S and P (3 fg and 1.7 fg. cell-1 instead of 163 and 6.3 fg. cell-1, respectively).

Comparison for the simultaneous determination of 237Np and Pu isotopes between TEVA and TK200 resin

A reliable and stable method was developed to accurately analyze neptunium (237Np) and plutonium isotopes in environmental samples using 242Pu or 236Pu as a tracer. Key parameters, including the valence adjustment conditions and the stabilities of Pu and Np in the different resins, were investigated using TK200 and TEVA resin. It was found that Pu and Np could be efficiently extracted simultaneously using TK200 resin under the optimal loading conditions (6–12 M HNO3) with the addition of 0.01–0.12 M NaNO2 for valence adjustment. These isotopes were subsequently stripped out using a solution containing 0.1 M HCl, 0.05 M HF, and 0.01 M NH2OH·HCl. The separation efficiencies of Pu and Np were >93%, and the chemical yield ratio between Np and Pu was maintained steady at an average of 1.00 ± 0.03 (n > 50) under the optimal conditions. The analytical method was validated by analyzing environmental soil samples spiked with known amounts of 239Pu and 237Np standard solutions or certified reference materials. The measured values of 237Np, 239Pu, and 240Pu obtained by inductively coupled plasma tandem mass spectrometry were consistent with their International Atomic Energy Agency literature values within a 95% confidence interval. These results confirm the reliability and high analytical precision (<6%) of this developed method using Pu as a non-isotopic tracer for monitoring the chemical yield of 237Np. The developed method can also be used for environmental pollutant monitoring and for tracer studies of the 237Np and Pu isotopes.

Development of a novel strategy for the quantification of ultra-trace impurity elements in high-purity magnesium using inductively coupled plasma tandem mass spectrometry

High purity magnesium is not only an important basic raw material for semiconductor and electronics industries, but also a promising new generation of electrochemical energy storage materials and biomedical materials. Impurities in high-purity magnesium affect material properties, which has become the most critical factor restricting its application. However, accurate analysis of multiple ultra-trace impurity elements in high-purity magnesium is extremely challenging. In this paper, based on the synergistic effect of N2O/H2 reaction gas mixture to eliminate spectral interference of inductively coupled plasma tandem mass spectrometry (ICP-MS/MS), a new strategy for the quantification of 45 ultra-trace impurity elements in high-purity magnesium was proposed. The results indicated that the limits of detection (LOD) were in the range of 0.02–18.5 ng L − 1; the LODs of the challenging non-metallic elements Si and S were 18.5 and 12.2 ng L − 1, respectively; and the LODs of all the other analytes were less than 10 ng L − 1. Even under hot plasma conditions, LODs of alkali metal elements were also less than 5 ng L − 1. The spike recovery of each analyte was 93.6%–107%, and the relative standard deviation (RSD) was 3.2%–6.9%, respectively. At a 95% level of confidence, no significant differences were found between the results obtained under the optimal conditions for the analyte with the developed method and the measurement results of SF-ICP-MS. The developed method indicated low LOD, high sample throughput, and complete interference elimination, demonstrating a new avenue for the rapid determination of ultra-trace elements in high-purity magnesium.

Determination of xanthates as Cu(II) complexes by high-performance liquid chromatography - Inductively coupled plasma tandem mass spectrometry.

The present study provides a novel, selective analysis method for the determination of low xanthate concentrations. The rising concern over the environmental effects of xanthates demands the development of analysis methods which this study answers. Complex formation in aqueous solution between xanthates and an excess of Co(II), Ni(II), Pb(II), Cd(II), Cu(II), and Zn(II) ions was utilized to selectively determine xanthates by high-performance liquid chromatography-inductively coupled plasma tandem mass spectrometry for the first time. The complexes that were formed were extracted to ethyl acetate using liquid-liquid extraction and separated by high-performance liquid chromatography technique before the quantitative determination of metal ions and sulfur in the xanthate complexes. Good separation and high measurement sensitivity were achieved using Cu(II) as the complex metal ion. The analysis method was optimized for the determination of sodium isopropyl xanthate and sodium isobutyl xanthate with detection limits of 24.7 and 13.3μg/L, respectively. With a linear calibration range of 0.1-15mg/L and a total analysis time of 4-5min, the present method is a fast and sensitive option for selective xanthate determination.