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At least 379 records · Page 21Linked to original sources
USGS1989

Influence of coupling of sorption and photosynthetic processes on trace element cycles in natural waters

Chemical and biological processes have important roles in the transport and cycling of trace elements in natural waters, but their complex interactions are often not well understood. Trace-element concentrations may, for example, be controlled by adsorption-desorption reactions at mineral surfaces, with the equilibrium strongly influenced by pH. Variations in pH due to photosynthetic activity should result in concentration fluctuations as the adsorption-desorption equilibrium shifts with pH. To investigate these interactions, we have studied the effect of diurnal cycling of pH on dissolved arsenate in a perennial stream contaminated with arsenic. As expected, a diurnal cycle in arsenate concentration was observed, but surprisingly, the arsenate cycle lags several hours behind the pH cycle. Laboratory experiments show that the lag results from a slow approach to sorption equilibrium. Our observations demonstrate that the coupling of photosynthesis and sorption processes may have an important influence on the cycling of many trace elements and emphasize the importance of understanding sorption kinetics in modelling these processes.

Nature↗
USGS2020

Morphological, elemental, and boron isotopic insights into pathophysiology of diseased coral growth anomalies

Growth anomalies (GAs) impact both coral skeleton and soft tissues and are detrimental to reef health. This tumor-like disease is increasingly found throughout the tropics and is commonly associated with high human population density, yet little is known about the etiology, pathology, or calcification behavior of the disease. Here, we investigate potential mechanisms involved in the development of GAs through chemical and morphological characterization of GA skeletons in Porites compressa from a site of high disease prevalence (Coconut Island, Hawaii). A comprehensive suite of trace elements and boron isotopes (δ11B) were measured in skeletal GAs to assess calcification behavior and uptake of essential and toxic metals. Scanning electron microscopy of GA skeleton revealed it to be highly porous consisting of a matrix with a disorganized crystal structure, in contrast to the dense well-organized normal skeleton of P. compressa. Elemental analyses revealed decreased Mg/Ca and increased U/Ca in GA skeletons relative to paired unaffected samples, suggesting a decreased abundance of rapidly accreting microstructures “centers of calcification” in the GAs. Estimates of carbonate system parameters based on δ11B and B/Ca measurements indicate reduced pH (–0.05 units) and [CO32–] within the calcifying fluid of GAs, which may have implications for GA calcification. Higher levels of essential (V/Ca and Mo/Ca) elements in GAs potentially indicate increased abundance of holobiont-associated, nitrogen-fixing bacteria and higher Sb/Ca and Nd/Ca indicate alteration in the accumulation/depuration of these toxic metals. In aggregate, our findings show that dystrophic calcification processes could explain structural differences seen in GA vs unaffected skeletons and highlight the use of approaches herein to shed light on disease pathophysiology in corals.

Scientific Reports↗
USGS1998

Re-evaluation and extension of the scope of elements in US Geological Survey Standard Reference Water Samples

More than 100 US Geological Survey (USGS) Standard Reference Water Samples (SRWSs) were analyzed for numerous trace constituents, including Al, As, B, Ba, Be, Bi, Br, Cd, Cr, Co, Cu, I, Fe, Pb, Li, Mn, Mo, Ni, Rb, Sb, Se, Sr, Te, Tl, U, V, Zn and major elements (Ca, Mg, Na, SiO2, SO4, Cl) by inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry. In addition, 15 USGS SRWSs and National Institute of Standards and Technology (NIST) standard reference material (SRM) 1641b were analyzed for mercury using cold vapor atomic fluorescence spectrometry. Also USGS SRWS Hg-7 was analyzed using isotope dilution-inductively coupled plasma mass spectrometry. The results were compared with the reported certified values of the following standard reference materials: NIST SRM 1643a, 1643b, 1643c and 1643d and National Research Council of Canada Riverine Water Reference Materials for Trace Metals SLRS-1, SLRS-2 and SLRS-3. New concentration values for trace and major elements in the SRWSs, traceable to the certified standards, are reported. Additional concentration values are reported for elements that were neither previously published for the SRWSs nor traceable to the certified reference materials. Robust statistical procedures were used that were insensitive to outliers. These data can be used for quality assurance/quality control purposes in analytical laboratories.

Analyst↗
USGS2008

Chlorinated, brominated, and perfluorinated compounds, polycyclic aromatic hydrocarbons and trace elements in livers of sea otters from California, Washington, and Alaska (USA), and Kamchatka (Russia)

Concentrations of organochlorine pesticides (DDTs, HCHs, and chlordanes), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polycyclic aromatic hydrocarbons (PAHs), perfluorinated compounds (PFCs), and 20 trace elements were determined in livers of 3- to 5-year old stranded sea otters collected from the coastal waters of California, Washington, and Alaska (USA) and from Kamchatka (Russia). Concentrations of organochlorine pesticides, PCBs, and PBDEs were high in sea otters collected from the California coast. Concentrations of DDTs were 10-fold higher in California sea otters than in otters from other locations; PCB concentrations were 5-fold higher, and PBDE concentrations were 2-fold higher, in California sea otters than in otters from other locations. Concentrations of PAHs were higher in sea otters from Prince William Sound than in sea otters from other locations. Concentrations of several trace elements were elevated in sea otters collected from California and Prince William Sound. Elevated concentrations of Mn and Zn in sea otters from California and Prince William Sound were indicative of oxidative stress-related injuries in these two populations. Concentrations of all of the target compounds, including trace elements, that were analyzed in sea otters from Kamchatka were lower than those found from the US coastal locations.

Alaska, California, Washington↗
USGS2012

Simulation of an urban ground-water-flow system in the Menomonee Valley, Milwaukee, Wisconsin using analytic element modeling

A single-layer, steady-state analytic element model was constructed to simulate shallow ground-water flow in the Menomonee Valley, an old industrial center southwest of downtown Milwaukee, Wisconsin. Project objectives were to develop an understanding of the shallow ground-water flow system and identify primary receptors of recharge to the valley. The analytic element model simulates flow in a 18.3 m (60 ft) thick layer of estuarine and alluvial sediments and man-made fill that comprises the shallow aquifer across the valley. The thin, laterally extensive nature of the shallow aquifer suggests horizontal-flow predominates, thus the system can appropriately be modeled with the Dupuit-Forchheimer approximation in an analytic element model. The model was calibrated to the measured baseflow increase between two USGS gages on the Menomonee River, 90 head measurements taken in and around the valley during December 1999, and vertical gradients measured at five locations under the river and estuary in the valley. Recent construction of the Milwaukee Metropolitan Sewer District Inline Storage System (ISS) in the Silurian dolomite under the Menomonee Valley has locally lowered heads in the dolomite appreciably, below levels caused by historic pumping. The ISS is a regional hydraulic sink which removes water from the bedrock even during dry weather. The potential effect on flow directions in the shallow aquifer of dry-weather infiltration to the ISS was evaluated by adjusting the resistance of the line-sink strings representing the ISS in the model to allow infiltration from 0 to 100% of the reported 9,500 m 3 /d. The best fit to calibration targets was found between 60% (5,700 m 3 /d) and 80% (7,600 m 3 /d) of the reported dry-weather infiltration. At 60% infiltration, 65% of the recharge falling on the valley terminates at the ISS and 35% at the Menomonee River and estuary. At 80% infiltration, 73% of the recharge terminates at the ISS, and 27% at the river and estuary. Model simulations suggest that the ISS has an greater influence on the shallow ground-water flow in the eastern half of valley as compared to the western half. Preliminary three-dimensional simulations using the numerical MODFLOW code show good agreement with the single-layer simulation and supports its use in evaluating the shallow system. Copyright ASCE 2004.

Conference Paper↗
USGS1976

Trace-element variations at Summer Coon volcano, San Juan Mountains, Colorado, and the origin of continental-interior andesite

The Oligocene Summer Coon center, an eroded continental-interior volcano of the eastern San Juan Mountains, Colorado, was the source of magmas ranging in composition from basaltic andesite to rhyolite. Previous Pb and Sr isotope studies indicate derivation of the magmas from an isotopically homogeneous source. This study presents new data for rare-earth elements (REE), U, Th, Ba, Sr, Rb, and Ni from 10 samples of the Summer Coon sequence. Alkali elements are high in all rocks; as SiO 2 increases, Ba increases from 900 to 2,000 ppm, Rb increases from 35 to 90 ppm, Sr decreases from 900 to 350 ppm, K/Rb decreases slightly, Ba/Sr increases, U increases from 0.5 to 2.5 ppm, and Th increases from 2 to 7 ppm. Chondrite-normalized REE patterns are strongly fractionated in comparison with oceanic-arc andesite-dacite sequences. La is 80 to 120 times chondritic abundance, but Yb and Lu are less than 10 times chondritic abundance. Small negative Eu anomalies characterize the rhyolites. Nickel in the andesites is 40 to 70 ppm. The origin of the andesite is interpreted in terms of nonmodal partial melting of a trace-element—enriched garnet-bearing source, possibly subducted crust that has converted to eclogite. Rhyodacite and rhyolite are interpreted as low-pressure crystal-fractionation products of silicic andesite, in which crystallizing phases are hornblende rich in REE and plagioclase.

Colorado↗
USGS2006

U-Pb SHRIMP geochronology and trace-element geochemistry of coesite-bearing zircons, North-East Greenland Caledonides

Obtaining reliable estimates for the timing of eclogite-facies metamorphism is critical to establishing models for the formation and exhumation of high-pressure and ultrahigh-pressure (UHP) metamorphic terranes in collisional orogens. The presence of pressure-dependent phases, such as coesite, included in metamorphic zircon is generally regarded as evidence that zircon growth occurred at UHP conditions and, ifdated, should provide the necessary timing information. We report U-Pb sensitive high-resolution ion microprobe (SHRIMP) ages and trace-element SHRIMP data from coesite-bearing zircon suites formed during UHP metamorphism in the North- East Greenland Caledonides. Kyanite eclogite and quartzofeldspathic host gneiss samples from an island in J??kelbugt (78??00'N, 18??04'W) contained subspherical zircons with well-defined domains in cathodoluminescence (CL) images. The presence of coesite is confirmed by Raman spectroscopy in six zircons from four samples. Additional components of the eclogite-facies inclusion suite include kyanite, omphacite, garnet, and rutile. The trace-element signatures in core domains reflect modification of igneous protolith zircon. Rim signatures show flat heavy rare earth element (HREE) patterns that are characteristic of eclogite-facies zircon. The kyanite eclogites generally lack a Eu anomaly, whereas a negative Eu anomaly persists in all domains of the host gneiss. The 207 Pb- corrected 206 Pb/ 238 U ages range from 330 to 390 Ma for the host gneiss and 330-370 Ma for the kyanite eclogite. Weighted mean 206 Pb/ 238 U ages for coesite-bearing domains vary from 364 ?? 8 Ma for the host gneiss to 350 ?? 4 Ma for kyanite eclogite. The combined U-Pb and REE data interpreted in conjunction with observed CL domains and inclusion suites suggest that (1) Caledonian metamorphic zircon formed by both new zircon growth and recrystallization, (2) UHP metamorphism occurred near the end of the Caledonian collision, and (3) the 30-50m.y. span of ages records long residence times at eclogite-facies conditions for the UHProcks of North-East Greenland. This spread in observed ages is interpreted to be characteristic of metamorphic rocks that have experienced relatively long (longer than 10 m.y.) residence times at UHP conditions. ?? 2006 Geological Society of America.

Special Paper of the Geological Society of America↗
USGS2025

Tracing metal sources and groundwater flow paths in the Upper Animas River watershed using rare earth elements and stable isotopes

Groundwater flow paths and processes that govern metal mobility and transport are difficult to characterize in mountainous bedrock watersheds. Despite the difficulty in holistic characterization, conceptual understanding of subsurface hydrologic and geochemical processes is key to developing remediation plans for locations affected by acid mine drainage, such as the Upper Animas River watershed in southwestern Colorado, USA. Stable isotopes of water and rare earth elements were utilized to evaluate groundwater flow and metal sources within this complex catchment. Stable isotope samples collected from draining mine adits and springs display systematic spatial variation wherein sample sites at higher elevations have greater seasonal variability than sites at lower elevations. The Upper Cement Creek watershed, where multiple draining mines are present, displays the lowest seasonal variation in stable isotopic signatures, potentially indicating the presence of a large, well-mixed volume of groundwater storage or interbasin groundwater flow. Rare earth elements display statistically significant variation between different alteration styles in the catchment. Overprinting of regional propylitic alteration is evident based on enrichment of middle rare earth elements in acidic springs and mines that are not spatially associated with surficial exposures of acid generating alteration styles. Europium anomaly and middle rare earth enrichment signatures from two flooded mine tunnels on opposite sides of a watershed divide indicate connections to the same subsurface flooded mine workings.

Colorado↗
USGS1997

Rare earth elements in weathering profiles and sediments of Minnesota: Implications for provenance studies

The relative abundance of rare earth elements in sediments has been suggested as a tool for determining their source rocks. This correlation requires that weathering, erosion, and sedimentation do not alter the REE abundances, or do so in a predictable manner. We find that the rare earth elements are mobilized and fractionated by weathering, and that sediments derived from the weathered materials can display modifications of the original pattern of rare earth elements of some due to grain-size sorting of the weathered material. However, the REE distribution pattern of the provenance terrane can be recognized in the sediments.

Journal of Sedimentary Research↗
USGS2016

Atomic weights of the elements 2013 (IUPAC Technical Report)

The biennial review of atomic-weight determinations and other cognate data has resulted in changes for the standard atomic weights of 19 elements. The standard atomic weights of four elements have been revised based on recent determinations of isotopic abundances in natural terrestrial materials: cadmium to 112.414(4) from 112.411(8), molybdenum to 95.95(1) from 95.96(2), selenium to 78.971(8) from 78.96(3), and thorium to 232.0377(4) from 232.038 06(2). The Commission on Isotopic Abundances and Atomic Weights (ciaaw.org) also revised the standard atomic weights of fifteen elements based on the 2012 Atomic Mass Evaluation: aluminium (aluminum) to 26.981 5385(7) from 26.981 5386(8), arsenic to 74.921 595(6) from 74.921 60(2), beryllium to 9.012 1831(5) from 9.012 182(3), caesium (cesium) to 132.905 451 96(6) from 132.905 4519(2), cobalt to 58.933 194(4) from 58.933 195(5), fluorine to 18.998 403 163(6) from 18.998 4032(5), gold to 196.966 569(5) from 196.966 569(4), holmium to 164.930 33(2) from 164.930 32(2), manganese to 54.938 044(3) from 54.938 045(5), niobium to 92.906 37(2) from 92.906 38(2), phosphorus to 30.973 761 998(5) from 30.973 762(2), praseodymium to 140.907 66(2) from 140.907 65(2), scandium to 44.955 908(5) from 44.955 912(6), thulium to 168.934 22(2) from 168.934 21(2), and yttrium to 88.905 84(2) from 88.905 85(2). The Commission also recommends the standard value for the natural terrestrial uranium isotope ratio, N ( 238 U)/ N ( 235 U)=137.8(1).

Pure and Applied Chemistry↗
USGS2016

U-Pb, Re-Os, and Ar/Ar geochronology of rare earth element (REE)-rich breccia pipes and associated host rocks from the Mesoproterozoic Pea Ridge Fe-REE-Au deposit, St. Francois Mountains, Missouri

Rare earth element (REE)-rich breccia pipes (600,000 t @ 12% rare earth oxides) are preserved along the margins of the 136-million metric ton (Mt) Pea Ridge magnetite-apatite deposit, within Mesoproterozoic (~1.47 Ga) volcanic-plutonic rocks of the St. Francois Mountains terrane in southeastern Missouri, United States. The breccia pipes cut the rhyolite-hosted magnetite deposit and contain clasts of nearly all local bedrock and mineralized lithologies. Grains of monazite and xenotime were extracted from breccia pipe samples for SHRIMP U-Pb geochronology; both minerals were also dated in one polished thin section. Monazite forms two morphologies: (1) matrix granular grains composed of numerous small (<50 μ m) crystallites intergrown with rare xenotime, thorite, apatite, and magnetite; and (2) coarse euhedral, glassy, bright-yellow grains similar to typical igneous or metamorphic monazite. Trace element abundances (including REE patterns) were determined on selected grains of monazite (both morphologies) and xenotime. Zircon grains from two samples of host rhyolite and two late felsic dikes collected underground at Pea Ridge were also dated. Additional geochronology done on breccia pipe minerals includes Re-Os on fine-grained molybdenite and 40 Ar/ 39 Ar on muscovite, biotite, and K-feldspar. Ages (±2 σ errors) obtained by SHRIMP U-Pb analysis are as follows: (1) zircon from the two host rhyolite samples have ages of 1473.6 ± 8.0 and 1472.7 ± 5.6 Ma; most zircon in late felsic dikes is interpreted as xenocrystic (age range ca. 1522–1455 Ma); a population of rare spongy zircon is likely of igneous origin and yields an age of 1441 ± 9 Ma; (2) pale-yellow granular monazite—1464.9 ± 3.3 Ma (no dated xenotime); (3) reddish matrix granular monazite—1462.0 ± 3.5 Ma and associated xenotime—1453 ± 11 Ma; (4) coarse glassy-yellow monazite—1464.8 ± 2.1, 1461.7 ± 3.7 Ma, with rims at 1447.2 ± 4.7 Ma; and (5) matrix monazite (in situ)—1464.1 ± 3.6 and 1454.6 ± 9.6 Ma, and matrix xenotime (in situ)—1468.0 ± 8.0 Ma. Two slightly older ages of cores are about 1478 Ma. The young age of rims on the coarse glassy monazite coincides with an Re-Os age of 1440.6 ± 9.2 Ma determined in this study for molybdenite intergrown with quartz and allanite, and with the age of monazite inclusions in apatite from the magnetite ore ( Neymark et al., 2016 ). A 40 Ar/ 39 Ar age of 1473 ± 1 Ma was obtained for muscovite from a breccia pipe sample. Geochronology and trace element geochemical data suggest that the granular matrix monazite and xenotime (in polygonal texture), and cores of coarse glassy monazite precipitated from hydrothermal fluids during breccia pipes formation at about 1465 Ma. The second episode of mineral growth at ca. 1443 Ma may be related to faulting and fluid flow that rebrecciated the pipes. The ca. 10-m.y. gap between the ages of host volcanic rocks and breccia pipe monazite and xenotime suggests that breccia pipe mineral formation cannot be related to the felsic magmatism represented by the rhyolitic volcanic rocks, and hence is linked to a different magmatic-hydrothermal system.

Missouri↗
USGS1962

Trace element distribution in the searchlight, Nevada quartz monzonite stock

Gold, silver, copper, and lead-bearing veins, non-radially zoned, occur just beyond the southern and western margins of the Searchlight , Nevada , quartz monzonite stock . Seven samples of the quartz monzonite and purified individual constituent minerals of the rock, representing apophyses and marginal and interior parts of the intrusive mass, were analyzed petrographically and spectrographically. A semiquantitative total-energy spectrographic method proved satisfactory for Cu, Pb, Ni, Co, Ga, Mo, Mn, Ti, V, Cr, Sr, and Zr, but too insensitive for Zn, Ag, and Au. A synthetic silicate base was used for preparation of standards and working curves. The modal trace element content of unaltered (hypothetical) quartz monzonite samples was determined from the trace element content of the purified minerals. Ferromagnesian minerals contain concentrations of Cu, Pb, Ni, Co, Mn, and Cr. Felsic minerals are low in these but high in Sr and Ga. Cu appears to have been partly released during chloritization of the mafic minerals. Ni, Cr, Zr show little difference between the unaltered (hypothetical) and actual rock. Ga, V, Mn, Sr are in lesser quantities in the altered rock. Pb and Cu also show a loss, especially nearest largest Pb and Cu producers. Pb, Cu, V occur in the spatially related veins, but Sr or Ga have not been reported to date. Pb/Cu in unaltered rock compared to altered rock is 1.6/1; past mining production ratio of Pb/Cu is 2.6/1. While further work is needed, the trace element pattern suggests a possible means of identifying a "productive" intrusive body.

Economic Geology↗
USGS1961

Occurrence of minor elements in water

Three basic studies, using spectrographic methods, have been used to establish the occurrence of minor elements in natural waters. One study, of oceanborne chemicals in principal rivers, has established a method for the quantitative analysis of many minor elements. Strontium, barium, lithium, rubidium, chromium, nickel, copper, lead, boron, titanium, molybdenum, manganese, and vanadium occur most frequently in measurable quantities. Reconnaissance of the strontium in surface waters of the United States, shows that surface waters in parts of northern and western Texas and southern New Mexico and Arizona are comparatively high in strontium. A study of minor elements in selected waters of California is continuing. Assessment of preliminary data on uranium and radium in waters is facilitated by grouping data for 10 geotectonic regions of the United States.

Circular↗
USGS2006

Organic Compounds, Trace Elements, Suspended Sediment, and Field Characteristics at the Heads-of-Tide of the Raritan, Passaic, Hackensack, Rahway, and Elizabeth Rivers, New Jersey, 2000-03

Concentrations of suspended sediment, particulate and dissolved organic carbon, trace elements, and organic compounds were measured in samples from the heads-of-tide of the five tributaries to the Newark and Raritan Bays during June 2000 to June 2003. The samples were collected as part of the New Jersey Department of Environmental Protection Toxics Reduction Workplan/Contaminant Assessment Reduction Program. Samples of streamwater were collected at water-quality sampling stations constructed near U.S. Geological Survey gaging stations on the Raritan, Passaic, Hackensack, Rahway, and Elizabeth Rivers. Sampling was conducted during base-flow conditions and storms. Constituent concentrations were measured to determine the water quality and to calculate the load of sediment and contaminants contributed to the bays from upstream sources. Water samples were analyzed for suspended sediment, dissolved organic carbon, particulate organic carbon, and specific conductance. Samples of suspended sediment and water were analyzed for 98 distinct polychlorinated biphenyl congeners, 7 dioxins, 10 furans, 27 pesticides, 26 polycyclic aromatic hydrocarbons, and the trace elements cadmium, lead, mercury, and methyl-mercury. Measurements of ultra-low concentrations of organic compounds in sediment and water were obtained by collecting 1 to 3 grams of suspended sediment on glass fiber filters and by passing at least 20 liters of filtered water through XAD-2 resin. The extracted sediment and XAD-2 resin were analyzed for organic compounds by high- and low-resolution gas chromatography mass-spectrometry that uses isotope dilution procedures. Trace elements in filtered and unfiltered samples were analyzed for cadmium, lead, mercury, and methyl-mercury by inductively coupled charged plasma and mass-spectrometry. All constituent concentrations are raw data. Interpretation of the data will be completed in the second phase of the study.

Data Series↗
USGS2006

Major and trace elements in 35 lake and reservoir sediment cores from across the United States, 1994-2001

This report presents data on major and trace element concentrations in sediment cores collected from 35 lakes and reservoirs during 1994-2001. The lakes and reservoirs are located in or near 18 major urban areas across the United States and provide a geographically diverse coverage of urban land use for the country as well as some reference settings. Vertical intervals of the cores were analyzed for eight major elements and eight trace elements.

Arizona, California, Colorado, Florida, Georgia, I↗
USGS2010

Stream-sediment samples reanalyzed for major, rare earth, and trace elements from seven 1:250,000-scale quadrangles, south-central Alaska, 2007-09

During the 1960s through the 1980s, the U.S. Geological Survey conducted reconnaissance geochemical surveys of drainage basins throughout most of the Iliamna, Lake Clark, Lime Hills, and Talkeetna 1:250,000-scale quadrangles and parts of the McGrath, Seldovia, and Tyonek 1:250,000-scale quadrangles in Alaska. These geochemical surveys provide data necessary to assess the potential for undiscovered mineral resources and provide data that may be used to determine regional-scale element baselines. This report provides new data for 1,075 of the previously collected stream-sediment samples. The new analyses include a broader spectrum of elements and provide data that are more precise than the original analyses. All samples were analyzed for arsenic by hydride generation atomic absorption spectrometry, for gold, palladium, and platinum by inductively coupled plasma-mass spectrometry after lead button fire assay separation, and for a suite of 55 major, rare earth, and trace elements by inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry after sodium peroxide sinter at 450 degrees Celsius.

Data Series↗
USGS2016

Elemental analysis using a handheld X-Ray fluorescence spectrometer

The U.S. Geological Survey is collecting geologic samples from local stream channels, aquifer materials, and rock outcrops for studies of trace elements in the Mojave Desert, southern California. These samples are collected because geologic materials can release a variety of elements to the environment when exposed to water. The samples are to be analyzed with a handheld X-ray fluorescence (XRF) spectrometer to determine the concentrations of up to 27 elements, including chromium.

Fact Sheet↗