Ultratrace Elements Research Articles

Inspirations of Cobalt Oxide Nanoparticle Based Anticancer Therapeutics.

Cobalt is essential to the metabolism of all animals due to its key role in cobalamin, also known as vitamin B12, the primary biological reservoir of cobalt as an ultra-trace element. Current cancer treatment strategies, including chemotherapy and radiotherapy, have been seriously restricted by their side effects and low efficiency for a long time, which urges us to develop new technologies for more effective and much safer anticancer therapies. Novel nanotechnologies, based on different kinds of functional nanomaterials, have been proved to act as effective and promising strategies for anticancer treatment. Based on the important biological roles of cobalt, cobalt oxide nanoparticles (NPs) have been widely developed for their attractive biomedical applications, especially their potential for anticancer treatments due to their selective inhibition of cancer cells. Thus, more and more attention has been attracted to the preparation, characterization and anticancer investigation of cobalt oxide nanoparticles in recent years, which is expected to introduce novel anticancer treatment strategies. In this review, we summarize the synthesis methods of cobalt oxide nanoparticles to discuss the advantages and restrictions for their preparation. Moreover, we emphatically discuss the anticancer functions of cobalt oxide nanoparticles as well as their underlying mechanisms to promote the development of cobalt oxide nanoparticles for anticancer treatments, which might finally benefit the current anticancer therapeutics based on functional cobalt oxide nanoparticles.

Element Contents in Three Commercially Important Edible Mollusks Harvested off the Southwestern Coast of Crimea (Black Sea) and Assessment of Human Health Risks from Their Consumption.

Mollusks are a prospective food for the world’s growing population, but the contents of toxic and essential trace elements in them have not been studied comprehensively. In this work, using inductively coupled plasma mass spectrometry, the contents of 72 elements in soft tissues of the edible mollusks Mytilus galloprovincialis, Rapana venosa, and Crassostrea gigas from the coastal area of the southwestern Crimea were estimated and compared with the maximum permissible levels. Element accumulation similarities were observed in the two bivalve species. Cluster analysis applied to the non-normalized contents allowed finding an optimal number of non-overlapping element clusters: 1 group of macroelements, 1–2 groups of trace elements, and 1–2 groups of ultratrace elements. As an outcome of this analysis, the element accumulation universality index was introduced, which demonstrated the accumulation universality decrease in the order: mussel > sea snail > oyster. An original approach to estimating the mollusk consumption rate was proposed to assess human health risks. Two possible consumption scenarios were identified for Crimean residents. From the expected consumption of all species in both scenarios, there are no health risks, but they are not excluded, within the 95% probability, from high consumption of mussels and sea snails in the pessimistic scenario.

Human biomonitoring of essential, nonessential, rare earth, and noble elements in placental tissues

Exposure to certain metals has been recognized as a risk factor for numerous complications in vulnerable population groups, particularly pregnant women. This investigation evaluated the levels of essential (Cr, Mn, Co, Cu, Zn, Se, Mo) and nonessential trace metals with recognized toxicity (Be, Al, Ti, V, Ni, Ga, As, Rb, Sr, Cd, Sb, Ba, Tl, Hg, Pb, Bi, Th, U), together with rare earth elements (Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu), and noble metals (Ru, Rh, Pd, Re, Os, Ir, Pt, Au, Ag) in the placental tissues of healthy pregnant women (n = 105). The selection of participants was undertaken with special reference to specific confounding factors that could influence the trace element profiles. Among trace elements, Zn was the most abundant and Lu was the least abundant. Cd and Os placental levels show a tendency to increase with women's age. Compared with literature data, high levels of Ni were found. This is the first study that provides the composition levels of essential and toxic trace elements, rare earth elements, and noble metals in human placental tissues. Also, for the first time, normal (reference) ranges for 50 (ultra)trace elements in placental tissues are proposed. Reference ranges are especially important in biomonitoring studies, which nowadays give increasing importance to the analysis of solid tissues instead of body fluids. Overall, the information provided in this study can serve as a starting point for further clinical trials and/or prediction of potential risks to pregnancy.

Assessment of Macro-, Micro-, Trace, and Ultratrace Element Concentration in Green-Legged Partridge Hens’ Eggs from a Free-Range System

The goal of this research was to determine the concentration of macro-, micro-, trace, and ultratrace elements in egg albumen and yolk of Green-Legged Partridge (GLP) hens (Polish native breed) maintained in a free-range system. The hens received two feed mixtures (FM), which differed in mineral content (Gr-1 and Gr-2). Analyses of 57 chemical elements were performed using inductively coupled plasma spectroscopy by ICP-OES and ICP-MS techniques. FM from Gr-2 were characterized by a significantly (p < 0.05 or 0.01) higher concentration of macro- and microelements (Al, Ba, Ca, K, P, S, Si) than that from Gr-1. Among the trace and ultratrace elements there were significantly higher levels of Co, Cr, Li, Nb, Ni, Pb, Ru, Sn, and Zr, and significantly lower levels of Cs, Pd, and Te in Gr-2 compared with Gr-1. Egg albumen from hens from the Gr-2 group contained a significantly higher Ba concentration. In the case of trace and ultratrace elements, significantly greater Au, Co, Cr, Mo, Nb, Ru, and Se, and less As were recorded in the albumen from Gr-2. No significant differences were observed in the concentrations of macro- and microelements in the egg yolk. Among the examined trace and ultratrace elements, substantial differences were observed in the level of Co, Cr, Ni, Se, Sn, and Y (more in Gr-2), and Au, Hf, Hg, Nb, Nd, and Rb (less in Gr-2). Only in the case of Co and Cr concentrations in the feed (Gr-2) was a significant increase found in the albumen and yolk. Gr-2 also showed a significantly greater concentration of Ba, Nb, and Ru in the albumen, and Ni and Sn in the yolk.

Potential of total‐reflection X‐ray spectrometry for multielement analysis of biological samples using dilution or suspension sample preparation techniques

In most clinical and nutritional studies, it is of significance to know information about the multielemental composition of biological samples. Conventional analysis of biological samples relies upon sample digestion followed by atomic spectrometry detection. This approach is essential for the quantification of ultratrace elements in biological samples. While in other applications it could be of interest to have simpler analytical methods with multielemental capability but involving a minimum sample treatment, reduce the amount of sample and a more cost‐effective analysis. In the present contribution, the possibilities and drawbacks of simple sample treatments (i.e., dilution and suspension) in combination with total reflection X‐ray fluorescence spectrometry (TXRF) for the analysis of different types of biological samples have been critically evaluated. For that, a set of reference materials or well‐characterized biological human fluids (blood, serum, plasma and seminal plasma) and animal/vegetal tissues have been used to estimate the analytical capabilities in terms of limits of detection, trueness and precision of the proposed TXRF methods. The results are based on the authors' experience in analysing biological samples using TXRF, and it is expected that they can be useful for new TXRF users in this field and they can provide a good basis for further application of this technique in clinical studies and other applications dealing with the analysis of biological samples in the future.

Application of Metallic Nanoparticles and Their Hybrids as Innovative Sorbents for Separation and Pre-concentration of Trace Elements by Dispersive Micro-Solid Phase Extraction: A Minireview.

It is indisputable that separation techniques have found their rightful place in current analytical chemistry, considering the growing complexity of analyzed samples and (ultra)trace concentration levels of many studied analytes. Among separation techniques, extraction is one of the most popular ones due to its efficiency, simplicity, low cost and short processing times. Nonetheless, research interests are directed toward the enhancement of performance of these procedures in terms of selectivity. Dispersive solid phase extraction (DSPE) represents a novel alternative to conventional solid phase extraction (SPE) which not only delivers environment-friendly extraction with less solvent consumption, but also significantly improves analytical figures of merit. A miniaturized modification of DSPE, known as dispersive micro-solid phase extraction (DMSPE), is one of the most recent trends and can be applied for the extraction of wide variety of analytes from various liquid matrices. While DSPE procedures generally use sorbents of different origin and sizes, in DMSPE predominantly nanostructured materials are required. The aim of this paper is to provide an overview of recently published original papers on DMSPE procedures in which metallic nanoparticles and hybrid materials containing metallic particles along with other (often carbon-based) constituent(s) at the nanometer level have been utilized for separation and pre-concentration of (ultra)trace elements in liquid samples. The studies included in this review emphasize the great analytical potential of procedures producing reliable results in the analysis of complex liquid matrices, where the detection of target analyte is often complicated by the presence of interfering substances.

Hydrogen, trace, and ultra-trace element distribution in natural olivines

We investigate the coupling between H, minor, trace, and ultra-trace element incorporations in 17 olivines from ten different locations covering various petrological origins: magmatic, hydrothermal, and mantle-derived context. Concentrations in major element are determined by micro X-ray fluorescence. Minor, trace, and ultra-trace elements are determined by laser ablation inductively coupled plasma mass spectrometry. Hydrogen concentrations are quantified using unpolarized and polarized Fourier transform infrared spectroscopy (FTIR). Forsterite contents (83.2–94.1%) reflect the petrogenetic diversity. Hydrogen concentrations range from 0 to 54 ppm H2O wt. Minor element concentrations (Ni + Mn) range from 3072 to 4333 ppm, and impurities are dominated by Ni, Mn, Ca or B. Total trace element concentrations range from 8.2 to 1473 ppm. Total rare Earth and extended ultra-trace elements concentrations are very low (< 0.5 ppm). Magmatic and hydrothermal olivines show the most and least amount of impurities, respectively, and mantle-derived olivines have concentrations between these two extremes. Combined with minor, trace, and ultra-trace element concentrations, the hydrogen concentrations, and FTIR OH bands reflect the point defect diversity imposed by different geological settings. Hydrogen concentrations are inversely correlated with divalent impurities, indicating their competition for vacancies. However, a broad positive correlation is also found between OH bands at 3575 and 3525 cm−1 and Ti, confirming the existence of Ti-clinohumite-like point defect in mantle olivines. Nonetheless, Ti does not exclusively control hydrogen incorporation in olivine due to the co-existence with other mechanisms, and its effect appears diluted. Our results confirm that hydrogen behaves as a peculiar incompatible element, and furthermore as an opportunistic impurity in olivine.

NUTRITION IN FASTING AND NON-FASTING WOMEN DURING THE GREAT ORTHODOX LENT

Aim: To compare nutrition of fasting and non-fasting women in Moscow. Methods: Daily intake of proteins, fats, carbohydrates and their fractions, water- and fat-soluble vitamins, macro-, micro- and ultra trace elements as well as the total caloric content of diet was estimated in 33 fasting and 32 non-fasting women during the Lent. Nutrition was assessed by frequency analysis using Nutrilogic software. Results: Fasting women had significantly higher intake of carbohydrates (412 g vs. 174 g) and fiber (42 g vs. 17 g), but lower intake of cholesterol (74 mg vs. 401 mg) and saturated fats (18 g vs. 30 g). Fasting women were less likely to consume insufficient amounts of vitamins B1 (12 % vs. 91 %), B3 (52 % vs. 91 %), B5 (52 % vs. 91 %), B6 (48 % vs. 88 %), B9 (42 % vs. 94 %) and E (24 % vs. 72 %), potassium (6 % vs. 41 %), magnesium (21 % vs. 91 %), iron (18 % vs. 81 %) and copper (3 % vs. 41 %). P &lt; 0.001 for all comparisons. All women consumed insufficient amount of vitamin D with food. Conclusion: Diet of fasting women had more favourable macro- and micronutrient composition and was richer in vitamins except vitamin D. This dietary pattern may be associated with health benefits in fasting women.

Sex- and sexual maturation-related aspects of the element accumulation in soft tissues of the bivalve Mytilus galloprovincialis Lam. collected off coasts of Sevastopol (southwestern Crimea, Black Sea).

Mussels are widely used to monitor trace element pollution, but the role of their sex and sexual maturation in the element accumulation was not comprehensively studied and the number of elements under consideration never exceeded three dozen. In this work, concentrations of 67 elements in different tissues of females and males of the Mediterranean mussel are determined. Statistically significant differences are obtained in the element composition of analogous tissues of mussel males and females and in gonads of the same sex at different sexual maturation stages. The significantly higher concentrations of some elements found in gonads of females (Mn, Zn, As) and males (P) at most of the sexual maturation stages suggest essentiality of these elements in the reproduction. Elements exhibit several accumulation patterns in gonads during the ripening, with the most general one being the accumulation after spawning. Indications of a new phenomenon of circulation of most elements in gonads over the reproductive cycle are obtained, with the element concentrations decreasing at the first two stages and increasing at the posterior stages. Principal component analysis shows that the differences in the element accumulation are mainly due to the element uptake pathways and sexual differentiation. The most important identified factors determining the decrease in concentrations of tissue elements are their redistribution over mussel's body, biomass dilution, sequestration, and release with gametes. Five detected non-overlapping clusters of the non-normalized element concentrations in the pooled mussel tissues are associated with macroelements, two groups of trace elements, and two groups of ultratrace elements.

Application of multi-isotope calibration to analysis of wine samples by ICP-MS

Analysis for trace (Cu, Fe, Sr, Zn) and ultra-trace (Cr, Ni, Pb, Sn) elements in table wines using the multi-isotope calibration technique was closely correlated with results measured by conventional external calibration with internal standards.

An optimized HNO3 and HBF4 digestion method for multielemental soil and sediment analysis using inductively coupled plasma quadrupole mass spectrometry

A robust and reliable analytical procedure for the determination of trace (mg∙kg−1) and ultra-trace elements (μg∙kg−1) in soil and sediments by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) was optimized. Aliquots of ∼200 mg of two certified reference materials (IAEA Soil-7, soil and IAEA SL-1, lake sediments) were digested in nitric acid (HNO3) purified twice by sub-boiling distillation using a microwave-heated high-pressure autoclave. Incremental addition of tetrafluoroboric acid (HBF4, 0.1–2 mL) to HNO3 was evaluated for yield. The selection of appropriate proportions of digestion acids was crucial to obtain accurate results. Digested samples were analyzed for a range of trace elements including those that are potentially toxic (Ag, Cd, Pb, Sb, and Tl), plant micronutrients (Cu, Fe, Mn, and Zn), those enriched in bitumen (Mo, Ni, and V), and lithophile elements (Al, Ba, Co, Cr, Rb, Sr, Th, Ti, Y, and Zr). Nitric acid alone proved to be sufficient to completely liberate Cd, Co, Cr, Fe, Mn, Ni, Pb, V, and Zn in both soil and sediments (87%–120% recovery). For almost all the other elements, addition of HBF4 was needed for improved recovery. A combination of 3 mL of HNO3 and 1.5 mL of HBF4 was optimal to fully liberate an extended list of elements including Ba, Sb, and Sr from both the reference materials. Conservative lithophile elements (Th, Ti, Y, and Zr) could not be completely recovered with the proposed method, requiring hydrofluoric acid for complete dissolution of recalcitrant minerals.

Nutrient Composition of Different Hazelnut Cultivars Grown in Germany.

Hazelnuts are rarely cultivated in Germany, although they are a valuable source for macro- and micronutrients and can thus contribute to a healthy diet. Near the present, 15 varieties were cultivated in Thuringia, Germany, as a pilot study for further research. The aim of our study was to evaluate the micro- and macronutrient composition of representative, randomly mixed samples of the 15 different hazelnut cultivars. Protein, fat, and fiber contents were determined using established methods. Fatty acids, tocopherols, minerals, trace elements, and ultra-trace elements were analyzed using gas chromatography, high-performance liquid chromatography, and inductively coupled plasma triple quadrupole mass-spectrometry, respectively. We found that the different hazelnut varieties contained valuable amounts of fat, protein, dietary fiber, minerals, trace elements, and α-tocopherol, however, in different quantities. The variations in nutrient composition were independent of growth conditions, which were identical for all hazelnut varieties. Therefore, each hazelnut cultivar has its specific nutrient profile.

New Soil Reference Material Validation for Trace and Rare-Earth Elements by High-Resolution Inductively Coupled Plasma Mass Spectrometry

Inductively coupled plasma mass spectrometry (ICP-MS) has become inevitable for quantitative determination of trace and ultra-trace elements in geological samples. Inferences derived from ICP-MS data sets and other supportive evidence have revolutionized theories on geology/geodynamics. In this scenario, validation through interlaboratory studies plays an important role in assuring the quality of measurements, along with the performance and accreditation programs of the laboratory. The Geological Survey of India (GSI) initiated an interlaboratory testing program on soil and stream sediment testing in which about fifteen laboratories, including our geochemical laboratory participated. Trace and rare-earth elements (REE) determined on the reference material PKS-1 by high-resolution ICP-MS and validated with the certified values for PKS-1 provided by GSI after compilation. The fitness of acquired data for either “pure geochemistry” or “applied geochemistry” was determined based on the Z-scores. The data for most of the analytes fell within the -2 < Z < + 2 range, which included the majority of the trace and REE used in petrogenetic and provenance studies. These results help to review the analytical mismatches observed in the data, optimize necessary aspects and minimize the interference effects caused during analysis.

Sodium orthovanadate inhibits growth of acute leukemia HL60 cells and HL60/A cells in vitro

Vanadium is an ultratrace element. The transition metal vanadium, widely exists in the environment and exhibits various biological and physiological effects in the human body, yet with no presently known specific physiological function in mammals. Sodium orthovanadate (SOV) is a kind of vanadium compound. SOV has shown promising antineoplastic activity in several human cancers. But the effects of SOV on acute promyelocytic leukemia (APL) are still unknown. In the present study, for the first time, we found that SOV could inhibit proliferation, induce G2/M cell cycle arrest and apoptosis, and could inhibit autophagy of acute leukemia cell lines in vitro. Thus, our findings suggest that SOV could effectively suppress the growth of acute leukemia HL60 cells and HL60/A cells through the regulations of proliferation, cell cycle, apoptosis and autophagy, and thus may act as a potential therapeutic agent in APL treatment.

The Effects of the Metal Ion Substitution into the Active Site of Metalloenzymes: A Theoretical Insight on Some Selected Cases

A large number of enzymes need a metal ion to express their catalytic activity. Among the different roles that metal ions can play in the catalytic event, the most common are their ability to orient the substrate correctly for the reaction, to exchange electrons in redox reactions, to stabilize negative charges. In many reactions catalyzed by metal ions, they behave like the proton, essentially as Lewis acids but are often more effective than the proton because they can be present at high concentrations at neutral pH. In an attempt to adapt to drastic environmental conditions, enzymes can take advantage of the presence of many metal species in addition to those defined as native and still be active. In fact, today we know enzymes that contain essential bulk, trace, and ultra-trace elements. In this work, we report theoretical results obtained for three different enzymes each of which contains different metal ions, trying to highlight any differences in their working mechanism as a function of the replacement of the metal center at the active site.

Correction to: Ultra-trace Element Characterization of the Central Ottawa River Basin Using a Rapid, Flexible, and Low-Volume ICP-MS Method

In the original publication of the article, the content under the section heading has been published incorrectly. Now the same has been corrected in this correction.

Investigation of Some Elements Concentrations and Distribution in Body parts and Organs of Japanese Quail Cotornix japonica

The presence, concentration and distribution of 42 trace and ultra trace elements in addition to rare earth elements (REE), yttrium(Y) and Thorium (Th) were analyzed using Inductively coupled plasma optical emission spectrometer (ICP-OES) in different body parts and organs of Japanese quail Cotornix japonica as a laboratory animal model. Twenty one of the investigated elements were below detection limit while the rest of the investigated elements varied in amount and distribution relative to organs and parts in which they were investigated. The existences, concentrations and distributions of Thallium (Tl) and europium (Er) are recorded in a higher living species by the present work. The present work also documented presence, concentration and distribution of Thulium (Tm) a living organism. The recorded concentrations and distributions of various elements may be related to their roles in structures and functions of organs in which they were distributed. From the present findings, we recommend better classification of elements according to distribution and concentration levels in individual organs. We also recommend investigation of the existence of Tm, Tl, and Er in other living species. We also recommend further investigation in the role of Tm, Tl, and Er in structure and metabolism of C. japonica parts and organs in which they were detected

Assessing Human Molybdenum Nutritional Status by Analyzing Frequency distribution Properties in the Hair and Whole Blood with a Median Derivatives Bioassay

Abstract Objectives Molybdenum is the essential trace element in human nutrition since it is a part of a pterin coenzyme which is essential for the activity of various oxidases. High doses of Mo are neurotoxic to the human brain. The safe adequate intake of Mo is set at 75–200 µg·g−1, but there is no available long-term biological indicator tissue to assess the Mo nutritional status. The aim of this study was to assess human Mo nutritional status with a median derivatives bioassay. Methods We analyzed frequency distribution of hair Mo (HMo) in a prospective, observational, cross sectional and exploratory epidemiological study of 1073 apparently healthy adults (339 men, M and 734 women, W) from Zagreb, CROATIA. Whole blood Mo (WBMo) was assessed in a population subsample of 143 W and 91 M. Both hair and whole blood, a long- and short-term biological indicator, respectively were analyzed for Mo with the ICP MS at the Center for Biotic Medicine, Moscow, Russia: an ISO certified bioelement (electrolytes, trace- and ultra-trace elements) analytical laboratory. Hair Mo natural frequency distribution was analyzed with the aid of median derivatives bioassay logistic sigmoid curve for men and women separately. The range of values below the linear segment of the sigmoid curve (the adequate Mo intake) was considered to reflect Mo deficiency, whereas the values above that linear range indicate Mo dietary excess. The adequate linear range may be further subdivided into marginal (subclinical), true adequate, and ample region with a 30:60:10 ratio, respectively. Results The linear segment of the hair Mo deposition was distinctly different (ng·g−1) and higher in M (34–75) than W (27–57) with the observed median ♀/♂ ratio 0.82. The marginal (subclinical) interval ranges are M 34–46.3, W 27–36). However, there were no difference in the WBMo confidence intervals between M (455–1380) and W (480–1145); the Median ♀/♂ observed ratio is 0.93. Conclusions Adequate human population Mo nutritional status may be accurately assessed by analyzing hair Mo frequency distribution with the median derivatives bioassay. Apparently, there is gender dependent delay of Mo hair saturation in the men hair. For the first time it was possible to differentiate the subclinical levels of sparsely adequate dietary Mo. Funding Sources Institute for Research and Development of Sustainable Eco Systems, 10,000 Zagreb, Croatia.

Age-Related Effects of Orthovanadate Nanoparticles Involve Activation of GSH-Dependent Antioxidant System in Liver Mitochondria.

Vanadium is an important ultra-trace element nowadays attracting attention with particular emphasis on medical application. But the therapeutic application of vanadium-based drugs is still questionable and restricted due to some toxic side effects. It was found that unique redox properties of vanadium in nanoform provided antioxidant activity and prevented oxidative disturbance in cells in vitro. Though, on the organism level, ambiguous effects of vanadium-based nanoparticles were observed. In this study, the age-related features of prooxidant/antioxidant balance in blood serum and liver mitochondrial and postmitochondrial fractions of 3 and 18-month-old Wistar male rats treated with orthovanadate nanoparticles (GdVO4/Eu3+, 8 × 25nm) within 2months have been investigated. Prooxidant potential-related indexes were the content of lipid hydroperoxides as well as aconitase activity. Activity of glutathione peroxidase, glutathione-S-transferase, glutaredoxin, glutathione reductase, glucose-6-phosphate dehydrogenase, and NADPH-dependent isocitrate dehydrogenase designated the tissue antioxidant potential. Based on the obtained values, the integral index of the prooxidant/antioxidant balance-the reliability coefficient (Kr) has been calculated. The data show that due to activation some chain links of GSH-dependent antioxidant system, GdVO4/Eu3+ nanoparticles increase the reliability of the prooxidant-antioxidant balance in tissues and especially in the liver mitochondria of old animals (Kr in mitochondria of young rats was 2.94, and in mitochondria of old ones-9.83 conventional units). Detected in vitro glutathione peroxidase-like activity of the GdVO4/Eu3+ nanoparticles is supposed to be among factors increasing the reliability of the system. So, for the first time, the beneficial effect of the long-term orthovanadate nanoparticle consumption in old males has been discovered.

Ultra-trace Element Characterization of the Central Ottawa River Basin using a Rapid, Flexible, and Low-volume ICP-MS Method

Ultra-trace (< 1 ng g−1) rare earth elements and yttrium (REE + Y) and high field strength element (HFSE) geochemistry of freshwater can constrain element sources, aqueous processes in hydrologic catchments, and the signature of dissolved terrestrial fluxes to the oceans. This study details an adapted method capable of quantifying ≥ 38 elements (including all REE + Y, Nb, Ta, Zr, Hf, Mo, W, Th, U) with minimal sample preparation in natural water aliquots as low as ≤ 2 mL. The method precision and accuracy are demonstrated using measurement of the National Research Council – Conseil national de recherches Canada (NRC-CNRC) river water certified reference material (CRM) SLRS-6 sampled from the Ottawa River (OR). Data from SLRS CRM are compared to those of new, filtered (< 0.45 µm) stream water samples from the central Ottawa River basin (ORB), and discussed in terms of processes and geochemical signatures inherited from the highly evolved igneous/metamorphic Archean and Proterozoic bedrock in the catchment. The ORB waters have significantly LREE > HREE-enriched REE + Y patterns, small natural positive Y and Gd anomalies, and negative Eu and Ce anomalies. These REE + Y features are coherent downstream in the OR apart from amplification of Eu and Ce anomalies during REE removal/dilution. The OR samples capture a downstream decrease in sparingly soluble HFSE (Th, Nb, Ta, Zr, Hf), presumably related to their colloid-particulate removal from the dissolved load, accompanied by crustal Zr/Hf (32.5 ± 5.1) and supercrustal Nb/Ta (25.1 ± 7.7) ratios. Subcrustal Th/U (0.17–0.96) and supercrustal Mo/W (12.0–74.5) ratios in all ORB waters indicate preferential release and aqueous solubility of U > Th and Mo > W, with the latter attributed primarily to preferential W adsorption on soil or upstream aquatic (oxy)(hydr)oxide surfaces.