Simultaneous Multi-element Analysis Research Articles

Multielement simultaneous quantitative analysis of trace elements in stainless steel via full spectrum laser-induced breakdown spectroscopy

Laser-Induced Breakdown Spectroscopy (LIBS) instruments are increasingly recognized as valuable tools for detecting trace metal elements due to their simplicity, rapid detection, and ability to perform simultaneous multi-element analysis. Traditional LIBS modeling often relies on empirical or machine learning-based feature band selection to establish quantitative models. In this study, we introduce a novel approach—simultaneous multi-element quantitative analysis based on the entire spectrum, which enhances model establishment efficiency and leverages the advantages of LIBS. By logarithmically processing the spectra and quantifying the cognitive uncertainty of the model, we achieved remarkable predictive performance (R2) for trace elements Mn, Mo, Cr, and Cu (0.9876, 0.9879, 0.9891, and 0.9841, respectively) in stainless steel. Our multi-element model shares features and parameters during the learning process, effectively mitigating the impact of matrix effects and self-absorption. Additionally, we introduce a cognitive error term to quantify the cognitive uncertainty of the model. The results suggest that our approach has significant potential in the quantitative analysis of trace elements, providing a reliable data processing method for efficient and accurate multi-task analysis in LIBS. This methodology holds promising applications in the field of LIBS quantitative analysis.

Feasibility of simultaneous multi-element analysis of quartz sand with impurities by calibration-free laser-induced breakdown spectroscopy and its potential for guiding glass manufacturing

As the main raw material in glass manufacturing, quartz sand and its elementary contents play an important role in glass quality. As raw quartz sand contains a variety of impurities such as metal oxides, which makes traditional chemical analysis methods for determining the chemical composition of quartz sand challenging and cumbersome, and the results are often influenced by the skill level of the analysts and various reagent factors. In this study, we investigate the feasibility of employing calibration-free laser-induced breakdown spectroscopy (CF-LIBS) for simultaneous multi-element analysis of the complex quartz sand. A Nd:YAG laser with a wavelength of 1064 nm and pulse width of 6 ns was used to irradiate the quartz sand sample, which resulted in generation of a plasma plume. The plasma spectra were recorded and analyzed to determine the type of element by finding the atomic (ion) characteristic spectral lines. The corresponding Boltzmann plane plot was drawn according to the relevant parameters of the characteristic spectral lines, and the plasma temperature was calculated. By measuring the Stark broadening of the characteristic spectral lines, the electron density of the plasma was evaluated, and the prerequisite of the local thermodynamic equilibrium of the plasma was verified. The results show that the CF-LIBS method can synchronously and quickly realize the multi-element identification of the sample without the need of a standard reference material. The use of CF-LIBS to measure the quartz sand raw material prior to entering the glass manufacturing process provides a guiding principle for formulating preliminary treatment plans based on the qualitative and quantitative measurement results.

Simulation of a continuum-source atomic absorption spectrometer

Continuum source atomic absorption spectrometry becomes a method for simultaneous multi-element analysis leading to a renewed interest in this method. The linear range of the calibration curve and the detection limits of continuum source atomic absorption spectrometers depend on the parameters of the instrumental function of the spectral instrument and the absorption line, the intensity of the radiation source, the level of radiation scattered in the instrument, and other factors. Calculating these dependences was the aim of this work. A theoretical model of the process of the absorption signal formation was constructed, and a computer program for its simulation was developed. Adequacy of the simulation was verified by comparing the absorption signals and calibration curves with the experimental ones obtained on a Grand-AAS spectrometer for several elements: Cd 228.8022 nm, Be 234.8610 nm, Mn 279.4817 nm, and Pb 283.3053 nm, as well as for the Ag 338.289 nm line recorded by two polychromators with different spectral resolution and scattered radiation levels. The relative deviation of the measured analytical signal from the simulated one did not exceed 15% in the concentration range of five orders of magnitude. The simulation results showed that nonlinearity of the calibration curve was primarily determined by the ratio of the width of the instrumental function (resolution) of the spectral instrument to the absorption line. The contribution of scattering in the spectrometer to the nonlinearity was secondary. The influence of the aperture characteristics of the photodetector arrays on the analytical signal was not significant. It was shown that decreasing resolution of the spectral instrument resulted in expanding the linear part of the calibration graphs from above to the level determined by scattering in the spectrometer. The detection limits limiting the graphs from below decrease with decreasing resolution until it approaches twice the width of the element's absorption line. After that, they start to increase.

Iodine stability as a function of pH and its implications for simultaneous multi-element ICP-MS analysis of marine carbonates for paleoenvironmental reconstructions

Analyses of marine carbonates using solution-based ICP-MS typically occur in dilute acid, as alkaline solutions can cause CaCO3 and metal-oxide/oxyhydroxide precipitation. Measurement of iodine to calcium (I/Ca) ratios in marine carbonates—most often in the calcite shells, or tests, of foraminifera—are challenging to pair with those of pH-sensitive metals, as iodine is unstable in acidic solution and will volatilize in the presence of light and air. As a result, I/Ca ratios are routinely analyzed in basic solution, requiring additional sample material and analytical time. Leveraging the equilibrium relationships between thermodynamically stable, inorganic iodine species across a wide range of electrochemical potential (pE) and pH values, we determine which species are present in low-temperature, aqueous solutions characteristic of marine carbonate analysis on quadrupole ICP-MS, and suggest appropriate solution pH(s) for iodine measurement. Our results demonstrate that iodine is capable of volatilization at all pH values <10.5, though it is most volatile in the pH range of 0–1. Furthermore, at pH values above 10.5, solutions are susceptible to contamination from gas-phase molecular iodine, I2.Employing this knowledge of iodine speciation, we establish a high precision method for the solution-based analysis of iodine alongside twelve other elements (Li, Na, Mg, Al, Mn, Fe, Zn, Sr, Cd, Ba, U, and Ca) on a collision-reaction cell equipped quadrupole ICP-MS in the acidic pH range. Using a 9:1 volume/volume mixture of 0.5% tetramethylammonium hydroxide (TMAH) and 2% nitric acid (HNO3), we can reproducibly analyze iodine concentrations in a complex carbonate (calcite and aragonite) matrix alongside other elemental ratios used in paleo-environmental reconstructions. This mixture of dilute acid and base maintains acidic pH (1.5 ± 0.14), avoiding the precipitation of pH-sensitive metal oxides/oxyhydroxides and CaCO3 while minimizing iodine volatilization. We demonstrate that iodine concentrations measured using ICP-MS are only effectively stabilized in the pH range of 1.5–10.5 and recommend pH-matching sample and standard solutions. This method allows the extraction of considerably more directly comparable paleo-environmental information from the analysis of a single foraminiferal sample.

Estimation of the possibility of controlling the temperature of an electrothermal atomizer by the signals of the element absorption

The current system of the temperature control for the electrothermal atomizer (ETA) used in atomic absorption spectrometers for simultaneous multielement analysis, is unable to provide high characteristics of the analysis when the calibration of the built-in optical pyrometer becomes irrelevant due to the natural wear of graphite cells upon operation. As the control of the ETA efficiency using an external calibrated pyrometer is laborious, it is advisable to use the dependence of temperature on the time of appearance of atomic vapors of elements. We have studied the possibility of controlling the temperature of graphite cells in the electrothermal atomizer of a multielement atomic absorption spectrometer with a continuous spectrum source by the time dependence of absorption signals of chemical elements. The correctness of the calibration was checked by recording the absorption signals of a sample containing chemical elements of different volatility with subsequent evaluation of the time and the corresponding temperature of the appearance of atomic vapors of the elements. The obtained temperatures of the appearance of atomic vapors of Al, Cd, In, Mn, Ni, Pb and V ranged within 640 – 1940°C. When the heating rate is changed by a factor of more than 3, the vapor appearance temperature for the selected elements differs by less than 5%. Using a deliberate change in the calibration of the built-in optical pyrometer, we have simulated a situation in which the relevance of the calibration was lost, e.g., due to the wear of a graphite cell. The experiment revealed a shift of the correlation graph between the actual and measured temperatures of the appearance of vapors of elements in the case of incorrect calibration of the feedback pyrometer in the coordinates «Real temperatures» — «Measured temperatures». The method presented in the study can be used to check the correctness of the calibration of the built-in pyrometer and to determine the necessity of replacing a worn graphite cell.

Quo vadis Spectroscopy?

Since the early days of modern chemistry, analytical chemistry always tried to offer solutions to real-life problems. This is how, in the midst of the Industrial Revolution, Margueritte developed the titrimetric determination of iron using the chameleon solution (potassium permanganate). In 1860, for the first time, Bunsen and Kirchhoff used element-specific light emission and absorption of flame-evaporated alkali metal salts for qualitative analysis. Their discovery was groundbreaking because the analytical sensitivity and detection capability of the proposed method was several orders of magnitude lower than that of the contemporary classical analytical ones. Application of this method, leading to the establishment of spectroscopic techniques, also allowed the discovery of about ten chemical elements. Another timeless merit of spectroscopy is the ability to determine the elemental composition of a star in a distant galaxy. In the second half of the 20th century, an era of rapid development of instrumental analysis, atomic spectroscopy also brought several revolutionary results. One such breakthrough was the reduction of the sample volume required for analysis down to microliters with the introduction of graphite furnace atomic absorption spectrometry (GFAAS). The detection limit of GFAAS also decreased by several orders of magnitude. Another important advance was the combination of inductively coupled plasma as a high-temperature ion source with a mass spectrometer (ICP-MS). In the late 1980s, the hyphenation of atomic spectrometric devices to chromatographs, aiming at elemental speciation, also emerged. In Central and Eastern Europe, spectroscopic research was driven by the embargo of the Coordinating Committee for Multilateral Export Controls established by the Western Bloc during the Cold War. In this emerging era, scientific research and applications went hand in hand. Therefore, the science education program and fundamental research were very strong in those countries, contributing considerably to the development of spectrochemistry in Hungary. By the end of the 20th century, development of new equipment and procedures was increasingly carried out by instrument manufacturers, and fundamental research at universities and institutes was relegated to second place. Analytical chemistry has experienced a considerable shift from determination of inorganic compounds and small organic molecules towards that of large (bio)molecules. Expansion of the application of analytical chemistry to forensic, environmental and biochemical questions has been observed and the role of atomic spectrometric techniques seemed to fade away. However, sheer use of these high-performance instruments is not always appropriate or cost-effective; the reliability of the results and elimination of interference must be thoroughly explored. However, when publishing such results, there is a risk that our communications will be rejected due to lack of novelty. Nevertheless, carrying out fundamental research cannot be avoided, as it is not possible to offer appropriate decisions to stakeholders based on questionable results. Presently, GFAAS and ICP-MS allow reliable quantitative determination of virtually any element in any sample. Recently, microwave plasma using nitrogen isolated from the air was launched on the market. This device requires significantly lower operating costs compared to the conventional ICP and reliable simultaneous multi-element analysis has also become possible. Another promising direction is single-particle ICP-MS applied for the characterization of inorganic nanoparticles. Most of the articles of the current issue of BrJAC also demonstrate that atomic spectrometry has become indispensable in many areas of our life. Enjoy reading the current issue!

Analyses of Li-Rich Minerals Using Handheld LIBS Tool

Lithium (Li) is one of the latest metals to be added to the list of critical materials in Europe and, thus, lithium exploration in Europe has become a necessity to guarantee its mid- to long-term stable supply. Laser-induced breakdown spectroscopy (LIBS) is a powerful analysis technique that allows for simultaneous multi-elemental analysis with an excellent coverage of light elements (Z &lt; 13). This data paper provides more than 4000 LIBS spectra obtained using a handheld LIBS tool on approximately 140 Li-content materials (minerals, powder pellets, and rocks) and their Li concentrations. The high resolution of the spectrometers combined with the low detection limits for light elements make the LIBS technique a powerful option to detect Li and trace elements of first interest, such as Be, Cs, F, and Rb. The LIBS spectra dataset combined with the Li content dataset can be used to obtain quantitative estimation of Li in Li-rich matrices. This paper can be utilized as technical and spectroscopic support for Li detection in the field using a portable LIBS instrument.

Broadband high-energy resolution hard x-ray spectroscopy using transition edge sensors at SPring-8.

We have succeeded in operating a transition-edge sensor (TES) spectrometer and evaluating its performance at the SPring-8 synchrotron x-ray light source. The TES spectrometer consists of a 240 pixel National Institute of Standards and Technology (NIST) TES system, and 220 pixels are operated simultaneously with an energy resolution of 4 eV at 6 keV at a rate of ∼1 c/s pixel-1. The tolerance for high count rates is evaluated in terms of energy resolution and live time fraction, leading to an empirical compromise of ∼2 × 103 c/s (all pixels) with an energy resolution of 5 eV at 6 keV. By utilizing the TES's wideband spectroscopic capability, simultaneous multi-element analysis is demonstrated for a standard sample. We conducted x-ray absorption near-edge structure (XANES) analysis in fluorescence mode using the TES spectrometer. The excellent energy resolution of the TES enabled us to detect weak fluorescence lines from dilute samples and trace elements that have previously been difficult to resolve due to the nearly overlapping emission lines of other dominant elements. The neighboring lines of As Kα and Pb Lα2 of the standard sample were clearly resolved, and the XANES of Pb Lα2 was obtained. Moreover, the x-ray spectrum from the small amount of Fe in aerosols was distinguished from the spectrum of a blank target, which helps us to understand the targets and the environment. These results are the first important step for the application of high resolution TES-based spectroscopy at hard x-ray synchrotron facilities.

Expanding the range of determination of elements on the Grand-AAS atomic absorption spectrometer using several of their absorption lines

One limitation of atomic absorption spectrometry is the narrow range of measurable concentration (1–2 orders of magnitude). In simultaneous multi-element analysis, this may require multiple dilutions of the sample to determine several elements with different concentrations in the sample. Possible ways to expand the range are to linearize the calibration curve by correcting the integral of the absorption signal or to use absorption values on the line wing as an analytical signal and plot several graphs along one line at different distances from its center. Both methods have their drawbacks. We propose another method for expanding the measurable concentration range by using less sensitive absorption lines of elements. A number of elements are identified that have a sufficient number of lines with different sensitivities. The proposed method is compared with the method of linearization of the calibration graph and the calculation of the absorption signal on the line wing. Using as an example Co and Ni, which have sufficiently rich absorption spectra, we have shown the possibility of expanding the measurable concentration range by using several absorption lines: for cobalt, the range is expanded to six orders of magnitude, and for nickel, to five orders of magnitude. Calibration curves are plotted in the concentration ranges 0.24–250.000 μg/L for cobalt and 1.9–250.000 μg/L for nickel. The calibration error is lower than that of the linearization method: 5% against 25 % for cobalt and 4% against 24% for nickel. Thus, the proposed method can be used for simultaneous multielement determination in a wide range of concentrations without diluting the sample.

Present-Day Possibilities of High-Resolution Continuous-Source Electrothermal Atomic Absorption Spectrometry

The review covers modern directions of the implementation of high-resolution continuous-source electrothermal atomic absorption spectrometry (HR CS ETAAS) for quantitative analysis. Approaches to the direct analysis of solid samples of various compositions, including determination using aqueous reference solutions, analysis of suspensions and sorbates after sorption separation, use of various modifiers, and optimization of the program of heating graphite furnace are systematized. Restrictions of HR CS ETAAS in the determination of poorly volatile elements are noted, methods for increasing the rate of their atomization in a graphite furnace are described. The potentials of HR CS ETAAS for the simultaneous and consecutive monitoring of atomic lines are investigated. The difference between the simultaneous multielement determination and consecutive determination in one aliquot portion is noted. Restrictions of simultaneous multielement analysis by HR CS ETAAS in the number of elements, their thermochemical properties, and intensities of corresponding absorption lines are described. Possibilities of molecular absorption spectrometry for the determination of analytes whose atomic absorption lines are outside the continuous spectrum range of 190–900 nm are discussed. A promising approach to the determination of sulfur, phosphorus, halogens, and aluminum by absorption lines of diatomic molecules is presented.

Simultaneous multielement analysis by ICP-MS with simple whole blood sample dilution and its application to uremic patients undergoing long-term hemodialysis

Few studies were reported on trace elements’ alterations in uremic patients undergoing long-term (>24 months) hemodialysis (HD), especially by using the whole blood as the biological fluid for the measuring purpose. Our objective was to develop an improved micro-sampling inductively coupled plasma-mass spectrometry (ICP-MS) method to determine the levels of Ca, Mg, Cu, Zn, Fe, Mn, Se and Pb in uremic patients receiving long-term HD. A ICP-MS method with a modified whole blood sample preparation procedure with small volumes was established and applied for the simultaneous quantification of the various elements in uremic patients undergoing long-term HD. 124 eligible uremic patients receiving long-term HD (75 males and 49 females) and 77 healthy subjects (54 males and 23 females) were recruited and Ca, Mg, Cu, Zn, Fe, Mn, Se and Pb levels were further determined. Our results revealed that uremic patients with HD had significantly higher blood levels of Ca, Mg, Zn and Pb and lower Cu, Fe, Se and Mn concentrations than healthy controls. In conclusion, a reproducible and reliable ICP-MS method using minimal whole blood sample volume (50 μL) with a simple dilution-based preparation procedure was successfully improved, validated and applied. Uremic patients undergoing long-term HD might be at increased risk of some essential trace elements deficiency (especially for Cu, Fe and Se) or toxic trace element excess (Pb) in respect to healthy subjects. Monitoring of blood levels and supplementation of some trace elements may be indicated in uremic patients undergoing long-term HD.

Methods for Nutrient Diagnosis of Fruit Trees Early in the Growing Season by Using Simultaneous Multi-element Analysis

Fruit tree nutrition is one of the most important factors in terms of growth and productivity. Measurement of nutritional requirements is an important aspect of nutrient management because nutritional disorders reduce yield and fruit quality. This review explores how nutrient imbalances affect the yield and fruit quality of fruit trees, and presents methods for diagnosing fruit tree nutritional disorders in order to correct nutritional deficiencies. In orchards, differences between soil sampling sites and locations of fruit tree roots when the root system is deep and unevenly distributed make it difficult to obtain representative soil samples from which to measure the forms of nutrients available to the trees. The delayed response of fruit trees to fertilizer applications compared with annual crops makes it difficult to determine their nutritional status through soil analysis immediately after application. In addition to soil analysis, plant tissue analysis is used to determine nutritional status and fruit tree nutritional requirements. In particular, earlier analysis in the growing season could allow sufficient time to correct any deficiencies before harvest. A recent approach that relies on analysis of the ionome, which is defined as the entire mineral nutrient and trace element complement in an organism, through simultaneous quantitative measurement enables comprehensive evaluation of multi-element composition. This approach could be especially effective as major decreases in yield and fruit quality are often caused by the interaction of several elements. Until recently, studies of fruit tree nutritional disorders have focused on particular nutrients, not multiple elements. Therefore, the application of ionomic analysis is a promising approach to elucidate multi-element interactions for accurate diagnosis of nutritional disorders.

Detection of soil organic matter from laser-induced breakdown spectroscopy (LIBS) and mid-infrared spectroscopy (FTIR-ATR) coupled with multivariate techniques

Spectroscopy is a useful method for soil monitoring because of its environmental friendliness, and its ability to produce rapid, nondestructive, simultaneous multi-element analysis. In this work, data fusion strategies for laser-induced breakdown spectroscopy (LIBS) and attenuated total reflectance Fourier-transform mid-infrared spectroscopy (FTIR-ATR), as well as a combination of multivariate calibration methods were investigated for prediction of soil organic matter (SOM) content. The root mean square error (RMSE) and residual prediction deviation (RPD) of the calibration and validation sets, systematic error, and residual assessment, were applied to evaluate the robustness and accuracy of these predictions. The results of a principal component analysis (PCA) indicated that baseline wander present in the spectral data could be effectively removed using morphological weighted penalized least squares (MPLS) and wavelet transform (WT) algorithms. The quantitative prediction ability of SOM content by a partial least squares regression (PLSR) model could be improved using principal component weighted mean (PCWM) and Euclidean distance weighted mean (EDWM) algorithms applied to parallel LIBS spectra. The prediction ability of SOM content was dramatically improved using mid-level data fusion based on the concatenation of latent variables of LIBS and FTIR-ATR spectra obtained by partial least squares algorithm. The considerable prediction accuracy and robustness were achieved using the PLSR model (RV2 = 0.792, RMSEV = 1.76 g kg−1, and RPDV = 2.16), the support vector regression (SVR) model (RV2 = 0.811, RMSEV = 1.68 g kg−1, and RPDV = 2.27), and the artificial neural network (ANN) model (RV2 = 0.830, RMSEV = 1.60 g kg−1, and RPDV = 2.39). The findings from this work suggest that the use of LIBS and FTIR-ATR spectra in combination with multivariate calibration can be a simple, fast, and nondestructive approach to monitor SOM. This strategy is potentially of great significance in the evaluation of soil fertility, the management of soil nutrients, and in guiding the agricultural production of precision agriculture.

Identification of the effects of long-term application of nitrogen fertilizer on the availability of 11 elements in soils and their supply to ‘Jonathan’ apple trees by using simultaneous multi-element analysis

The objective of this study was to investigate the effects of long-term application of ammoniacal N fertilizer for 43 years on the availability of 10 essential elements (B, N, Mg, K, Ca, Mn, Fe, Ni, Cu, and Zn) and Al in root-zone soils and their supply to ‘Jonathan’ apple trees. To achieve this objective, we used simultaneous multi-element analysis. To estimate the soil depth from which the apple trees took up these elements, we calculated the ratios of their concentrations in the N fertilized plot (N plot) to those in the no N plot (0 N plot) (N/0N ratio). Long-term N fertilization significantly increased the fruit and leaf N/0N ratios of N and Mn and significantly decreased that of K. These ratios in the fruits and leaves were similar to those in the 20–90 cm soil layer. This result suggests that N, K, and Mn in the fruits and leaves were supplied from the 20–90 cm soil layer. The N/0N ratios of all 11 elements in the fruits and leaves were significantly positively correlated with those in the 20–90 cm soil layer, but not in the 0–20 cm soil layer. Our findings indicate that long-term N fertilization altered the tree nutrition of not only N, but also K and Mn. These changes in the tree nutrition were ascribed to the fertilizer-induced changes in the availability of elements in the subsoils.

Combined Application of Imaging Methods for Estimating Soil Physicochemical Properties

Traditional techniques and methods for evaluation and detection of soil samples are tedious, laborious, expensive, and time-consuming. In comparison, spectroscopic techniques have successfully overcome some of these disadvantages and can supplement or replace them. As soil is a complex media, it is difficult to assign specifically spectral features for physicochemical properties of soil. This study discusses the combined application of Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR), and Scanning Electron Microscopy coupled to EDX microprobe (SEM/EDX) methods for estimating soil physicochemical properties. For this purpose, 30 topsoil samples were measured according to standard methods of soil analysis. All spectra were collected in the mid-infrared (MIR) from 4000 to 650 cm-1. Chemometric methods were used in the analysis of multivariate data using the Quant2 package in OPUS 7 software and improved the prediction of soil properties using partial least squares regression (PLSR). The results showed that specific surface area (SSA MB-titration) had the best predictions for the soil properties in ATR-FTIR study with a RPD of 2.08, RMSE of 13.50 m2 g–1, and R2 of 0.77 (very good); followed by cation exchange capacity, organic carbon, SSA (BET), Al, clay, and Ca (good); saturation, sand, silt/clay, electrical conductivity, saturated hydraulic conductivity, K, silt, Fe, C, and Si (fair); O, Mg, pH, bulk density, porosity, total pore volume, and particle density (poor). Also, we found that SEM-EDX is able to perform a rapid simultaneous multielement analysis without any special soil sample preparation. Consequently, modern techniques, such as ATR-FTIR and SEM-EDX can be used for such studies according to the information needed and the time required for the sample preparation.

Comparing laser induced breakdown spectroscopy, near infrared spectroscopy, and their integration for simultaneous multi-elemental determination of micro- and macronutrients in vegetable samples

Laser-induced breakdown spectroscopy (LIBS) is an appealing analytical technique for simultaneous multi-elemental analysis. Near-infrared spectroscopy (NIRS) has also been suggested for the same purpose, mainly for vegetable samples. However, LIBS has failed to provide adequate results in many cases due to sample matrix complexity, and NIRS performance is harmed because of its lack of sensitivity and indirect correlation with inorganic elemental species. In this work, the performance of these two techniques are compared for the determination of micro- and macroelements in vegetable samples (Brachiaria forages) using multivariate regression. In addition, a data fusion scheme, in which spectral data sourced by NIRS is integrated with LIBS, is proposed to improve elemental content determination in those samples. The information of the molecular composition detected by NIR vibrational spectroscopy was consistently selected by recursive partial least squares to yield quantitative multivariate models for K, Ca, Mg, Mn and Fe in forage plants that are superior to models based on the use of individual NIRS and LIBS spectral information. While all data fusion models showed better predictive accuracy than any of the two individual techniques, best results were observed for Ca. This suggests that matrix composition affects each element determination by LIBS distinctively and supports the idea that a successful quantitative data fusion strategy for LIBS requires a technique such as NIRS which is sensitive to this variability.

«Atom» software for atomic spectral analysis

«Atom» software is used in integrated spectral devices for atomic emission and atomic absorption analysis produced by «VMK-Optoélektronika». Development of the new spectral instruments and upgrading of existing devices, birth of new mathematical methods and algorithms for processing spectral information, as well as user stories motivate and promote improvement of the software. This paper presents the main developments and most noticeable changes in «Atom «software for the period 2017 – 2018. The developed 64-bit version of «Atom» software removed the limitation on the amount of recorded sequences of spectra and significantly speeded up their processing by parallelizing the calculations on the processor cores (rather important step, for example, in scintillation atomic emission spectrometry). To implement continuum source electrothermal atomic absorption spectrometry for simultaneous multi-element analysis, we have developed the «Automatic Dispenser» and «Absorption Spectrometer» tools and have implemented the method proposed by D.A. Katskov to linearize calibration dependences in a wide range of concentrations. The possibility of spectrophotometric determination of substances in the solutions of their mixtures has been also implemented. The «Barcode Scanner» and the «Automatic Start of Measurement» tools have been developed to speed up and automate the analysis procedure. The software is supplemented with a set of useful functions designed for further development of analytical methods and programs of analysis.

熱水性金鉱床試料の多元素同時分析：ICP-MSによる全岩および局所化学組成分析手法の検討

熱水性金鉱床試料の多元素同時分析：ICP-MSによる全岩および局所化学組成分析手法の検討

Alternating-Current-Driven Microplasma for Multielement Excitation and Determination by Optical-Emission Spectrometry.

Microplasma optical-emission spectrometry (OES) is a promising technique for developing portable analytical instrumentations for real-time and on-site measurement of trace elemental species. However, its analytical performance is far from satisfactory for multielement analysis. Herein, a miniature OES system is developed for simultaneous multielement analysis with alternating-current-driven microplasma generated on the nozzle of a pneumatic micronebulizer as the excitation source. Because of the strong excitation capability of the microplasma and its sufficient contact with solution, a series of elements, including Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, and Zn, is directly excited in the spray with solution nebulization at a flow rate of 8 μL s-1. The characteristic optical emissions are measured by a charge-coupled-device (CCD) spectrometer. In addition, hydride generation is compatible with the present system, which makes it feasible for the simultaneous excitation of hydrides of As, Ge, Hg, Sb, and Sn by reaction with 0.8% (m/v) NaBH4. The microplasma-OES system exhibits a powerful capability for multielement analysis with favorable limits of detection for the mentioned elements.

Simultaneous Determination of 11 Elements in Fly Ash by Inductively Coupled Plasma Orthogonal Acceleration Time-of-Flight Mass Spectrometry After Closed-Vessel Microwave-Assisted Extraction with Ammonium Fluoride

A method for simultaneous multi-element analysis of fly ash samples by inductively coupled plasma orthogonal acceleration time-of-flight mass spectrometry (oaTOF-ICP-MS) after closed-vessel microwave extraction with ammonium fluoride was introduced here. Corrosive and/or toxic acids like HF, HCl or HClO4, as well as HNO3, which are commonly used during sample preparation of the fly ash samples, are avoided in this method. The spectral effects due to the formation of different Cl, Na, K, Ca, Mg-containing polyatomic species interfering with the determination of a number of elements like As, Se or Ni during the oaTOF-ICP-MS analysis are negligible. Under the optimum experimental extraction conditions evaluated using a fractional factorial design (10 mg of the sample extracted with 5 mL of 140 g/L NH4F for 10 min at 200°C), analysis of the resulting supernatant with Rh as an internal standard enabled precise and accurate simultaneous determination of 11 elements (Li, Be, Ni, As, Se, Rb, Sb, Cs, W, Tl and U) at trace and ultratrace levels. The accuracy was assessed by analysing two certified reference materials, namely Fine Fly Ash CTA-FFA-1 and Constituent Elements in Coal Fly Ash Standard Reference Material® 1633b. The precision of the reported method was better than 10%.