High Resolution Inductively Coupled Plasma Mass Spectrometry Research Articles

Precise Determination of Eu Concentration in Coal and Sedimentary Rock Samples Using High-Resolution Inductively Coupled Plasma Mass Spectrometry (HR-ICP-MS)

Europium (Eu) in coal and sedimentary rocks has important mineral resource potential as well as being a crucial parameter in geochemical studies that can represent changes in the depositional environment during coal deposition and identify the depositional source region. Therefore, it is essential to realize the precise measurement of Eu in coal as this could be a useful parameter for paleoenvironmental reconstruction studies and the exploration of mineral resources. During inductively coupled plasma mass spectrometry (ICP-MS) analysis, polyatomic ions of Ba may interfere with Eu, causing the observed value to be higher than the actual value. This paper develops a new approach for Eu determination by using a high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The mass spectral interference and correction of Eu in the coal and sedimentary rock samples at low, medium, and high resolutions were investigated. The results showed that in the high-resolution mode (resolution = 10,000 amu), the interference of polyatomic ions of Ba could be distinguished from Eu; hence, Eu was determined under this circumstance. Under the optimal experimental circumstances, the detection limit was 0.006 μg/mL, the relative standard deviation was 0.80%–1.22%, and the linear correlation coefficient of the standard curve was over 0.9999. The recoveries of the 103Rh internal standard solution ranged from 94.41% to 100.10%. This method was verified using standard reference materials and selected samples, which demonstrated its high sensitivity, accuracy, and reliability, and a low detection limit, making it appropriate for detecting Eu in samples of coal and sedimentary rocks.

Occurrence, toxicity load, pollution index and health risk assessment of trace elements in drinking water of two catchments in North-western Himalayas

ABSTRACT The study focuses on the analysis of trace metals in drinking water from the Ganderbal and Budgam districts of Jammu and Kashmir. We have used high-resolution inductively-coupled plasma mass spectrometry (HR-ICP-MS) to measure the concentrations of 31 trace metals in the water samples. The measured concentrations were then compared with the permissible limits set by the United States Environmental Protection Agency (USEPA), Bureau of Indian Standards (BIS), and World Health Organization (WHO). The results of the study indicate that arithmetic mean of several trace elements, including aluminum (Al = 781), chromium (Cr = 139), manganese (Mn = 41.86), nickel (Ni = 25.89), molybdenum (Mo = 1.30), cadmium (Cd = 36.86), and mercury (Hg = 67.65), in µg l−1 were found to have concentrations higher than their respective permissible limits. On the other hand, the arithmetic mean of elements, such as beryllium (Be = 0.14), boron (B = 32.72), iron (Fe = 233), cobalt (Co = 1.79), copper (Cu = 10.71), arsenic (As = 0.93), selenium (Se = 3.13), strontium (Sr = 257), zinc (Zn = 43), antimony (Sb = 1.44), barium (Ba = 28.56), gold (Au = 0.91), and lead (Pb = 0.91) in µg l−1, had concentrations below the permissible limits recommended by USEPA, BIS, and WHO. To assess the toxicity of the heavy metals in the study area, we calculated the Heavy Metal Toxicity Load (HMTL) for each metal. Based on these calculations, we concluded that only cadmium (Cd) and chromium (Cr) need to be removed from drinking water to ensure safety. The study also conducted a health risk assessment for children and adults based on the measured concentrations of heavy metals. The assessment considered the ingestion and dermal contact routes of exposure. The Hazard Index (HI), which indicates the non-carcinogenic health effects, exceeded unity for only one element, cadmium (Cd), in the children and adult groups. This suggests potential non-carcinogenic health risks associated with the ingestion of water and dermal contact. Additionally, the potential carcinogenic risk of cadmium (Cd) and arsenic (As) was identified and recommended for further attention. The study further evaluated the Heavy Metal Pollution Index (HPI) to assess the overall quality of drinking water in the study area. The HPI results indicated that the quality of drinking water was good, and the pollution levels in the study area were low. Overall, the findings of this study provide valuable information for water resource development and supply agencies. The results can be used as a baseline for future research and monitoring efforts in the region.

Developments in analytical techniques for chemostratigraphy, chronostratigraphy, and geochemical fingerprinting studies: Current status and future trends

Chemostratigraphy utilizes the elemental, isotopic, and mineralogical compositions of sediments and rocks to understand the conditions of deposition and diagenesis, variations in paleo-redox conditions, climate, provenance, tectonic setting, and reservoir characteristics. This utility is based on the occurrences and stratigraphic variations of concentrations of certain elements, isotopes, minerals, and some organic compounds in sedimentary rocks. Significant progress has been made in the elemental, isotopic, and mineralogical determination techniques over the last couple of decades and this development is critically helpful to the applications of chemostratigraphy in widely varying fields including, but not limited to stratigraphy, depositional and diagenetic modelling, petroleum exploration, reservoir characterization, forensics, etc. Currently, highly precise data on about 60 elements in the range Li–U can be obtained very rapidly on a routine basis in different types of sediment samples such as drill cuttings, sediment cores, or hand specimens using various analytical techniques such as inductively coupled plasma mass spectrometry (ICP-MS), high resolution ICP-MS (HR-ICP-MS), and Mattauch–Herzog geometry ICP-MS (MH-ICP-MS). Elemental data as ratios of certain elements or proxy values in profile form with depth, isotope values, and certain ratios are used for understanding various geological processes in the earth's history. Mineralogical studies using techniques such as x-ray diffraction spectrometry (XRD) and Raman spectroscopy have proven to be very powerful for identifying different sedimentary successions belonging to different ages. There have been notable advances in the measurement of isotopic concentrations and isotopic ratios both in stable isotopes and radiogenic isotopes. Certain analytical techniques such as laser-induced breakdown spectroscopy (LIBS) are able to distinguish different rock types, their geographic sources, and the geological processes associated with their formation in a field setting in real-time. In addition to the instrumental developments, substantial progress is made in other critical areas such as sample preparation, sample decomposition, analytical protocols, development of international certified geochemical reference materials (CRMs), and quality issues in general. Until recently, the general approach in elemental and mineralogical chemostratigraphic studies was to follow time taking process of collecting the sediment/drill core samples in the field and bringing them to the laboratory to generate the analytical data. This is very expensive, time-consuming, and difficult for covering large areas. But, rapid advances in the area of analytical instrumentation saw some instruments such as x-ray fluorescence spectrometer (XRF), LIBS, visible and near-infrared spectrophotometer, and Raman spectrometer dramatically shrunk in size and have become portable, and changed this scenario completely and increased on-site applications in chemostratigraphy studies. In this review, these developments in analytical instrumentation in general together with some key applications in chemostratigraphy, chronostratigraphy, and geochemical fingerprinting have been summarized.

Impact of nutrients and trace elements on freshwater microbial communities in Croatia: identifying bacterial bioindicator taxa.

Since aquatic microbial communities promptly respond to environmental changes, it is now evident that they can complement traditional taxa such as fish, macroinvertebrates and algae as bioindicators of water quality. The aim of this study was to correlate the physico-chemical parameters of water with the microbial community structure and the occurrence of putative bioindicator taxa. Thirty-five water samples were collected throughout Croatia and their physico-chemical parameters, including the concentration of trace elements using the high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS), and the composition of the microbial communities by high-throughput sequencing of the 16S rRNA marker gene, were analysed in parallel. Partial least squares regression (PLS-R) modelling revealed that a number of microbial taxa were positively correlated with some of the water parameters. For example, some taxa from the phylum Proteobacteria were positively correlated with the ion content of the water (e.g. Erythrobacter, Rhodobacteraceae, Alteromonadaceae), while some Firmicutes taxa, such as the well-known faecal indicators Enterococcus and Clostridium, were correlated with nutrient content (ammonium and total phosphorus). Among the trace elements, uranium was positively correlated with a highest number of microbial taxa. The results obtained will aid in development of protocols for eDNA-based biological assessment of water quality.

Enriched high purity germanium detectors for the LEGEND-200 experiment: purification and characterization by quadrupole and high resolution inductively coupled plasma mass spectrometry (ICP-MS)

LEGEND-200 (Large Enriched Germanium Experiment for Neutrinoless ββ Decay) is a physics experiment at the Gran Sasso National Laboratories (LNGS) in Italy searching for neutrinoless double beta (0υββ) decay of 76Ge using enriched high purity germanium (HPGe) detectors with a total mass of about 200 kg.During the production of germanium crystals, especially during the crystal cutting, a fraction of the enriched germanium remains as metal residues. To reuse these residual materials again for crystal growing, they must be efficiently purified. A special plant was built to purify and convert Ge metal to GeO2.Quadrupole ICP-MS (Q-ICP-MS) and High Resolution ICP-MS (HR-ICP-MS) were used to characterize the starting materials, reaction and final products. The results of the analyses are presented here.

Metal ratios as possible biomarkers for amyotrophic lateral sclerosis

Background and ObjectivesAmyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with unknown aetiology. Metals have been suspected to contribute to ALS pathogenesis since mid-19th century, yet studies on measured metal concentrations in ALS patients have often yielded conflicting results, with large individual variation in measured values. Calculating metal concentration ratios can unveil possible synergistic effects of neurotoxic metals in ALS pathogenesis. The aim of this study was to investigate if ratios of different metal concentrations in cerebrospinal fluid (CSF) and blood plasma, respectively, differ between ALS patients and healthy controls. MethodsCerebrospinal fluid and blood plasma were collected from 17 ALS patients and 10 controls. Samples were analysed for 22 metals by high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS), and all possible 231 metal ratios calculated in each body fluid. ResultsFifty-three metal ratios were significantly elevated in ALS cases as compared to controls (p < 0.05); five in blood plasma, and 48 in CSF. The finding of fewer elevated ratios in blood plasma may indicate specific transport of metals into the central nervous system. The elevated metal ratios in CSF include Cd/Se (p = 0.031), and 16 ratios with magnesium, such as Mn/Mg (p = 0.005) and Al/Mg (p = 0.014). ConclusionMetal ratios may be used as biomarkers in ALS diagnosis and as guidelines for preventive measures.

Automated determination of gallium in seawater using seaFAST pre-concentration and high-resolution inductively-coupled plasma mass spectrometry

There has been increased interest in dissolved gallium (Ga) in natural waters due to its long residence time and its usefulness in tracking water masses; however, current analytical approaches are time consuming and labor intensive (e.g., magnesium hydroxide co-precipitation method, (Mg(OH)2)) or have concerns such as carryover and sample recovery (automated resin column extraction). Ocean observing programs, such as GEOTRACES, recover hundreds of samples per expedition. There are both logistical (sample volume) and analytical (person-hour) demands to economically collect and analyze Ga. We present an automated isotope dilution method (using 99.8% enriched 71Ga) to determine Ga in seawater utilizing commercially available equipment while addressing the challenges of a) sample volume and sample pre-concentration factor, b) instrumental interferences, c) sample-sample carryover, d) sample recovery variability, and e) improving sample detection limits, accuracy and precision. A seaFAST SC-4DXS pico (Elemental Scientific, Inc.; ESI) was used to pre-concentrate 20 mL of sample on a Nobias PA1 resin column 67-fold before analysis in medium resolution on a ThermoFisher high-resolution inductively-coupled plasma mass spectrometer (HR-ICP-MS) equipped with an APEX Q FAST enabled spray chamber (ESI) to increase signal intensity and decrease instrument interferences. The new automated seaFAST method reproduced Ga concentrations determined by the Mg(OH)2 method, but with greater precision (RSD <4%) and a lower detection limit (0.10 pmol L−1). This method is ideal for high throughput applications and can be easily implemented using commercially available equipment.

Heavy metals, rare earth elements and isotopic fingerprint of Venetian Protected Designation of Origin sparkling wines

PurposeWorld imports of Italian sparkling wines fell by 9% in value and 5% in quantities. In view of this, the quality characterisation of these products is desirable to increase their market value and restore their global visibility.Design/methodology/approachFor this purpose, in this paper, heavy metals (Cd, Co, Cr, Cu, Fe, Ga, Hf, Hg, Mn, Mo, Nb, Ni, Pb, Re, Sb, Sn, Ta, Th, Tl, U, W, V, Zn, Zr), rare Earth elements (REEs) (Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Tm, Yb) and isotopes ratio (208Pb/206Pb, 207Pb/206Pb, 206Pb/204Pb, 208Pb/207Pb, 87Sr/86Sr) were analysed in Italian sparkling wines with Protected Designation of Origin (PDO) certification by High Resolution Inductively Coupled Plasma Mass Spectrometry (HR-ICP-MS) and MultiCollector Inductively Coupled Plasma Mass Spectrometer (MC-ICP-MS). The samples were produced in the Veneto region, and they were compared to white and red wines from the same area.FindingsSparkling wines present a characteristic elemental pattern compared to white and red ones, with lower content of heavy metals and higher content in REEs. The ratio 87Sr/86Sr resulted in a powerful micro-scale geographical origins marker while Pb ratios as winemaking process one, both useful to prevent possible frauds. Multivariate data analyses, such as PCA and PLS-DA, were used to develop a model of recognition of Venetian sparkling wines.Originality/valueThe good classification of sparkling wines was achieved (95%), proving the suitable use of these analytes as markers for recognising sparkling wines and their geographical origin verification. To the best of the authors’ knowledge, this is the first study investigating heavy metals, REEs and isotopes in Venetian sparkling wine for their recognition.

Uranium in groundwater in parts of India and world: A comprehensive review of sources, impact to the environment and human health, analytical techniques, and mitigation technologies

Uranium concentration/contamination in groundwater is currently a subject of concern all over the world due to related severe health problems to humans, as groundwater is the main drinking water source in rural and urban India and also in several parts of the world. Uranium concentration in groundwater in shallow aquifers in various states such as Punjab, Rajasthan, Karnataka Telangana, and Madhya Pradesh of India varies from 0 to 1443 ng/ml exceeding the permissible levels by WHO for drinking water (30 ng/ml), at several places. Very high concentrations ranging up to 1400 ng/ml were reported in some areas in other countries such as Canada, the USA, Mongolia, Burundi, Zambia, Nigeria, South Korea, Pakistan, Jordon, Afghanistan, China, and Myanmar. Various natural aspects which influence the uranium concentration in groundwater such as bedrock geology, water chemistry, and redox conditions, and anthropogenic sources such as mining activities (uranium, coal, and phosphate rock), nuclear activities, agricultural practices of using phosphate fertilizers, and prevalence of excessive nitrate in some areas, are described with examples. Some of the important analytical techniques for the precise and accurate determination of elemental and isotopic concentrations of uranium in water samples, such as LED fluorimetry, Raman spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), high-resolution ICP-MS (HR-ICP-MS), and multi-collector ICP-MS (MC-ICP-MS), are described. A number of advancements have taken place in remediation technologies for the removal of uranium in drinking water using different physical, chemical, and biological methods including rainwater harvesting. Various mitigation strategies for the effective removal of uranium from water during treatment, such as bioremediation using biochars from different sources, nanoparticle technology, and adsorption by magnesium (Mg)-iron (Fe)-based hydrotalcite-like compounds (MF-HT), are described in detail.

Stability of selenium and its speciation analysis in water using automatic system separation and HR-ICP-MS measurement

A simple and convenient method has been developed for the pre-concentration and separation of inorganic selenium species from environmental water samples using anion exchange chromatographic column combined with high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) measurement. 75Se(IV) and 75Se(VI) were prepared and used as tracers during the experiments. The volatility of selenium during solution evaporation was investigated to establish a reliable water samples pretreatment procedure. The parameters which affect the uptake of Se(IV) and Se(VI) on Dowex1 × 8 resin was optimized and the procedure for Se(IV) and Se(VI) separation was proposed. Both Se(IV) and Se(VI) are retained on the column in natural or alkaline solution with high distribution coefficient. The successive gradient elution of pre-concentrated species of selenium with HNO3 solution allows to differentiate between them. Se(IV) and Se(VI) finally were eluted with 0.05 mol/L HNO3 and 5.0 mol/L HNO3, respectively. The proposed method has been successfully verified using the certified reference materials (CRMs) of real water samples, and spiked recoveries for real samples were 98%-104% with 5% relative standard deviations (RSDs). The developed procedure is proved to be reliable and can be used for the rapid determination of selenium species in environmental water samples.

Multiplex DNA Walking Machines for Lung Cancer-Associated miRNAs.

Biomimetic DNA walking machines have gained great success in scrutinizing the microscopic world and sensitive biosensing of disease biomarkers. Despite superb achievements, the research on DNA walking machines for simultaneous detection of multiple analytes is still rare, while the design and realization of multiplexing are considered as an important bottleneck. The multiplex detection of biomarkers can not only improve the specificity of bioassays but also avoid the squander of valuable biological specimens. Herein, we reported multiplex three-dimensional (3D) DNA walking machines based on high-resolution inductively coupled plasma mass spectrometry (HR-ICPMS) for lung cancer-associated miRNA detection. In the presence of lung cancer-associated target miRNAs (miR-21, miR-141, and miR-125b), DNA walking machines were stimulated and operated to liberate a large number of lanthanide elements (Tb, Ho, and Tm), and then the signals were collected simultaneously by HR-ICPMS. The recovery test of target miRNAs in human serum and the simultaneous monitoring experiment of three miRNAs in human lung cancer cell line (A549) and normal cell line (HBE) specimens display satisfactory analysis capabilities for complex biological samples. Thanks to the vast potential of lanthanide tags and the modular design, the proposed bioassay might flexibly detect different miRNA combinations with corresponding sets of DNA walking machines to meet the requirements of various tasks.

Tin and Antimony as Soil Pollutants along Railway Lines—A Case Study from North-Western Croatia

The aim of this study was to determine the extent and patterns of antimony and tin contamination in soils along railway lines, as there are very few data in the literature on this subject. The study was conducted in north-western Croatia. Total and bioavailable concentrations of Sn and Sb were detected using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The following results were obtained: total concentrations of Sb ranged from 0.98 to 52.0 mg/kg and of Sn from 3.04 mg/kg to 97.6 mg/kg. The soil samples showed pronounced Sb and Sn enrichment, up to 87 and 33 times the median value for European soils, respectively. In contrast to the total concentrations, the bioavailable concentrations showed relatively low values. For Sn, the percentage of total content ranged from 0.001 to 0.021%, while for Sb it ranged from 0.001 to 0.136%. Statistical data analysis suggests that the distribution of Sb and Sn in soils near railway lines is influenced by the functional use of the site, distance from the tracks, topography, age of the railway line, and also by soil properties such as soil texture, humus content, and soil pH. This study demonstrates that rail transport is a source of soil pollution with Sn and Sb. The origin of Sb and Sn enrichment is abrasion by brakes, rails, wheels, freight losses, exhaust gasses, etc. Both elements in soils along railway lines pose an environmental risk to humans, agricultural production, and wildlife, and therefore further detailed studies are required.

Oxidative potential and water-soluble heavy metals of size-segregated airborne particles in haze and non-haze episodes: Impact of the “Comprehensive Action Plan” in China

Air pollution is a major environmental health challenge in megacities, and as such a Comprehensive Action Plan (CAP) was issued in 2017 for Beijing, the capital city of China. Here we investigated the size-segregated airborne particles collected after the implementation of the CAP, intending to understand the change of oxidative potential and water-soluble heavy metal (WSHM) levels in ‘haze’ and ‘non-haze’ days. The DNA damage and the levels of WSHM were analyzed by Plasmid Scission Assay (PSA) and High-Resolution Inductively Coupled Plasma Mass Spectrometry (HR-ICP-MS) techniques. The PM mass concentration was higher in the fine particle size (0.43–2.1 μm) during haze days, except for the samples affected by mineral dust. The particle-induced DNA damage caused by fine sized particles (0.43–2.1 μm) exceeded that caused by the coarse sized particles (4.7–10 μm). The DNA damage from haze day particles significantly exceeded those collected on non-haze days. Prior to the instigation of the CAP, the highest value of DNA damage decreased, and DNA damage was seen in the finer size (0.43–1.1 μm). The Pearson correlation coefficient between the concentrations of water-soluble Pb, Cr, Cd and Zn were positively correlated with DNA damage, suggesting that these WSHM had significant oxidative potential. The mass concentrations of water-soluble trace elements (WSTE) and individual heavy metals were enriched in the finer particles between 0.43 μm to 1.1 μm, implying that smaller sized particles posed higher health risks. In contrast, the significant reduction in the mass concentration of water-soluble Cd and Zn, and the decrease of the maximum and average values of DNA damage after the CAP, demonstrated its effectiveness in restricting coal-burning emissions. These results have demonstrated that the Beijing CAP policy has been successful in reducing the toxicity of ‘respirable’ ambient particles.

Trace elements in whole blood in the general population in Trøndelag County, Norway: The HUNT3 Survey

BackgroundBiomonitoring of a cohort within a large health survey can provide reliable information on trace element status. The main aims of this study were 1) to determine the concentrations of 28 trace elements in whole blood samples from the general population of the Nord-Trøndelag region, Norway, and 2) to investigate how trace element concentrations vary with geographical area, lifestyle, and socio-demographic factors. MethodsWhole blood samples were collected in the third survey of the Trøndelag Health Survey (HUNT3), a large population-based study in Norway. In total, 1011 whole blood samples from individuals aged 20–91 years were analyzed using high resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS). We compared trace element concentrations (As, B, Be, Br, Ca, Cd, Cr, Cs, Cu, Ga, Au, In, Fe, Pb, Hg, Tl, Mg, Mn, Mo, Ni, Rb, Sc, Se, Ag, Sr, Sn, W and Zn) between three geographical areas (coastal, fjord/town, inland/mountain) using multivariable linear regression and assessed differences in trace element concentrations with socio-demographic and lifestyle factors using general linear models. ResultsTrace element concentrations were generally comparable to levels reported in other recent studies and suggest low exposure to toxic trace elements in the region. We found geographical differences in concentrations of 19 trace elements. As, Br, Hg, and Se concentrations were higher on the coast compared to the fjord/town and inland/mountain areas, suggesting that the marine environment is an important source of exposure for these trace elements. In addition, socio-demographic and lifestyle characteristics, particularly age and sex, were associated with differences in trace element concentrations. ConclusionsWe report concentrations of 28 trace elements in the general population of a rural region with low exposure to pollution. Whole blood concentrations of trace elements varied with geographical area, the participants' lifestyle, and socio-demographic characteristics, highlighting the importance of considering these factors when evaluating trace element status in a population.

Selenium enrichment in the marine microalga Nannochloropsis oceanica

Se-enriched ingredients have recently gained interest in the aquaculture industry as feed supplements due to their positive effects on fish health, growth, and potential effects on animal welfare. This study aims to assess which inorganic selenium (Se) species is suitable to produce Se-enriched Nannochloropsis oceanica (N. oceanica) biomass for aquafeed applications. The effective concentration for 50% growth inhibition (EC50) and Se bioaccumulation of the two inorganic forms of Se, sodium selenite (Na2SeO3), and sodium selenate (Na2SeO4), were assessed at different concentrations after twelve days of cultivation. Toxicity results showed that selenate, EC50 = 32.93 μM, had a greater negative effect on cell growth than selenite, EC50 = 163.82 μM. Total intracellular Se was analysed by inductively coupled plasma - optical emission spectrometry (ICP-OES) and high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS), which revealed that selenite was better accumulated by N. oceanica. Further investigation at 30 μM of selenite in the growth medium resulted in Se bioaccumulation with a minor effect on cell growth and reached a Se intracellular content of 0.131 gSe/kgbiomass after 12 days. Thus, 30 μM of selenite was selected for batch pilot-scale cultivation in a 1500 L tubular photobioreactor. Total Se accumulated in the biomass at pilot-scale was in the same order of magnitude compared with flasks (0.104–0.159 gSe/kgbiomass). The results from this pilot-scale study are fundamental for a proof of concept from laboratory to pilot-scale production and they represent a critical bridging step for the potential use of Se-enriched N. oceanica in aquafeed.

Quantification of Total Arsenic in South African Wheat Flour by High Resolution – Inductively Coupled Plasma – Mass Spectrometry (HR-ICP-MS)

A method for the determination of the total As concentration in wheat flour samples from South African crops was developed based on a microwave-assisted digestion procedure. Different aspects of sample preparation, as well as optimization of the instrumental technique, such as strategies for signal enhancement, were investigated. The optimum digestion procedure was achieved using 6 mL nitric acid (HNO3) with 40 µL hydrogen peroxide (H2O2) to facilitate the dissolution of the organic matter in the samples with gentle heating up to 95 °C over a period of 55 min. The analysis was performed using high resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS) for optimum interference control for As. The measurement trueness of the method was confirmed with an -value = 0.01 calculated for the NIST SRM 1568b (Rice Flour) and an -value = 0.9 calculated for the NCS ZC 80002b (Wheat) CRMs, respectively. The repeatability of the method was calculated to give a relative standard deviation (RSD) of <12%. The limit of detection (LOD) was 0.021 ng g−1 for the samples in solution and the limit of quantification (LOQ) was 0.069 ng g−1. This method was successfully applied to the analysis of 10 wheat flour samples with concentrations in the range of 5.5 to 12.3 ng As g−1 dry sample with a relative uncertainty of 11% (=2). The concentrations of As in wheat flour samples obtained in this study were below the permissible levels of As allowed in food and food products.

Elemental Testing Using Inductively Coupled Plasma Mass Spectrometry in Clinical Laboratories.

This review aims to describe the principles underlying different types of inductively coupled plasma mass spectrometry (ICP-MS), and major technical advancements that reduce spectral interferences, as well as their suitability and wide applications in clinical laboratories. A literature survey was performed to review the technical aspects of ICP-MS, ICP-MS/MS, high-resolution ICP-MS, and their applications in disease diagnosis and monitoring. Compared to the atomic absorption spectrometry and ICP-optical emission spectrometry, ICP-MS has advantages including improved precision, sensitivity and accuracy, wide linear dynamic range, multielement measurement capability, and ability to perform isotopic analysis. Technical advancements, such as collision/reaction cells, triple quadrupole ICP-MS, and sector-field ICP-MS, have been introduced to improve resolving power and reduce interferences. Cases are discussed that highlight the clinical applications of ICP-MS including determination of toxic elements, quantification of nutritional elements, monitoring elemental deficiency in metabolic disease, and multielement analysis. This review provides insight on the strategies of elemental analysis in clinical laboratories and demonstrates current and emerging clinical applications of ICP-MS.

Raman-XPS spectroscopy, REE chemistry, and surface morphology of Fe-Ti oxide heavy mineral sands: a case study from Varkala-Kovalam coast, south-west India

ABSTRACT The beach sands of the Varkala-Kovalam coast, south-west India, are enriched with heavy minerals with a high concentration of ilmenite followed by sillimanite, monazite, rutile, zircon, and garnet. The Fe–Ti oxide minerals such as ilmenite, its altered product leucoxene, and rutile were successfully recovered, and their structure, chemistry, and surface morphology were analysed using advanced characterisation techniques like Raman spectroscopy, Energy Dispersive X-ray Fluorescence (ED-XRF), High Resolution Inductively Coupled Plasma Mass Spectrometry (HR-ICP-MS), Thermogravimetric Analysis (TGA), UV-Visible-NIR (UV-Vis-NIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), and Scanning Electron Microscopy (SEM-EDS). The chemical composition, surface chemistry, the oxidation state of surface elements, anisotropic crystal behaviour of the minerals due to physical or chemical processes, discrimination of polymorphs, and finally the morphological changes due to mechanical impacts were also analysed. The study provides solid information to the scientific community and policymakers for determining the grade and potential applications of these strategic minerals.

Titanium dioxide nanoparticles in food: comparison of detection by triple-quadrupole and high-resolution ICP-MS in single-particle mode

We used triple-quadrupole and high-resolution inductively coupled plasma-mass spectrometry (ICP-MS) in single-particle mode to characterize the food additive E171 (titanium dioxide, TiO2) in chewing gum, chocolate candy, and cake decoration in the same sample extracts. Then, we spiked TiO2 particles (with similar characteristics as E171) to milk as an example of a calcium-rich matrix. The obtained particle size distributions with both techniques were highly similar in terms of shape and median and mean diameters. Median diameters were in the range of 123 to 209 nm and mean diameters from 146 to 223 nm. In addition, they were in agreement with results obtained by scanning electron microscopy and asymmetric flow field-flow fractionation coupled to multi-angle light scattering and ICP-MS. Repeatable determination of number-based particle size distributions was possible with both ICP-MS techniques even in a calcium-rich matrix showing that both instruments were similarly efficient in resolving the Ca interferences. The combination of spICP-MS with microscopy and TiO2 recovery allowed validating the methods and identifying the presence of aggregated/agglomerated particles in one sample. For the TiO2 powder and the two remaining food products, recoveries were higher than 60%. Both instruments are fit for purpose even if the analyses were performed with differences in detector mode, dwell times, and calculation tools. This shows that both techniques may be used as long as operating conditions are optimized and applicability range is defined.

Proposal of new distribution coefficients (Kd) of potentially toxic elements in soils for improving environmental risk assessment in the State of São Paulo, southeastern Brazil

Soil solid-solution distribution coefficients (Kd) are used in predictive environmental models to assess public health risks. This study was undertaken to determine Kd for potentially toxic elements (PTE) Cd, Co, Cr, Cu, Ni, Pb, and Zn in topsoil samples (0–20 cm) from 30 soils in the State of São Paulo, southeastern Brazil. Batch sorption experiments were carried out, and PTE concentrations in the equilibrium solution were determined by High Resolution Inductively Coupled Plasma Mass Spectrometry (HR-ICPMS). Sorption data was fitted to the Freundlich model. The Kd values were either obtained directly from the slope coefficients of C-type isotherms or derived from the slope of the straight line tangent to the non-linear L-type and H-type isotherms. Stepwise multiple regression models were used to estimate the Kd values through the combined effect of a number of soil attributes [pHH2O, effective cation exchange capacity (ECEC) and contents of clay, organic carbon, and Fe (oxy)hydroxides]. The smallest variation in Kd values was recorded for Cu (105-4598 L kg-1), Pb (121-7020 L kg-1), Ni (6-998 L kg-1), as variation across four orders of magnitude was observed for Cd (7–14,339 L kg−1), Co (2–34,473 L kg−1), and Cr (1–21,267 L kg−1). The Kd values for Zn were between 5 and 123,849 L kg−1. According to median values of Kd, PTE were sorbed in the following preferential order: Pb > Cu > Cd > Ni > Zn > Cr > Co. The Kd values were best predicted using metal-specific and highly significant (p < 0.001) linear regressions that included pHH2O, ECEC, and clay contents. The Kd values reported in this study are a novel result that can help minimize erroneous estimates and improve both environmental and public health risk assessments under humid tropical edaphoclimatic conditions.