Central Region Mineral Resources Science Center
Taggart, J.E., 2002, Analytical methods for chemical analysis of geologic and other materials, U.S. Geological Survey: U.S. Geological Survey Open-File Report 02-223.
Forty major, minor, and trace elements are determined in geological materials by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The sample is decomposed using a mixture of hydrochloric, nitric, perchloric, and hydrofluoric acids at low temperature. The digested samples is aspirated into the ICP-AES discharge where the elemental emission signal is measured simultaneously for the forty elements. Calibration is performed by standardizing with digested rock reference materials and a series of multi-element solution standards.
| Element | Concentration Range | |
|---|---|---|
| Aluminum, Al | 0.005 | 50% |
| Calcium, Ca | 0.005 | 50% |
| Iron, Fe | 0.02 | 25% |
| Potassium, K | 0.01 | 50% |
| Magnesium, Mg | 0.005 | 5% |
| Sodium, Na | 0.005 | 50% |
| Phosphorous, P | 0.005 | 50% |
| Titanium, Ti | 0.005 | 25% |
| Silver, Ag | 2 | 10,000 ppm |
| Arsenic, As | 10 | 50,000 ppm |
| Gold, Au | 8 | 50,000 ppm |
| Barium, Ba | 1 | 35,000 ppm |
| Beryllium, Be | 1 | 5,000 ppm |
| Bismuth, Bi | 50 | 50,000 ppm |
| Cadmium, Cd | 2 | 25,000 ppm |
| Cerium, Ce | 5 | 50,000 ppm |
| Cobalt, Co | 2 | 25,000 ppm |
| Chromium, Cr | 2 | 25,000 ppm |
| Copper, Cu | 2 | 15,000 ppm |
| Europium, Eu | 2 | 5,000 ppm |
| Gallium, Ga | 4 | 50,000 ppm |
| Holmium, Ho | 4 | 5,000 ppm |
| Lanthanum, La | 2 | 50,000 ppm |
| Lithium, Li | 2 | 50,000 ppm |
| Manganese, Mn | 4 | 50,000 ppm |
| Molybdenum, Mo | 2 | 50,000 ppm |
| Niobium, Nb | 4 | 50,000 ppm |
| Neodymium, Nd | 9 | 50,000 ppm |
| Nickel, Ni | 3 | 50,000 ppm |
| Lead, Pb | 4 | 50,000 ppm |
| Scandium, Sc | 2 | 50,000 ppm |
| Tin, Sn | 50 | 50,000 ppm |
| Strontium, Sr | 2 | 15,000 ppm |
| Tantalum, Ta | 40 | 50,000 ppm |
| Thorium, Th | 6 | 50,000 ppm |
| Uranium, U | 100 | 100,000 ppm |
| Vanadium, V | 2 | 30,000 ppm |
| Yttrium, Y | 2 | 25,000 ppm |
| Ytterbium, Yb | 1 | 5,000 ppm |
| Zinc, Zn | 2 | 15,000 ppm |
Data is deemed acceptable if recovery for all 40 elements is ±15% at five times the Lower Limit of Determination (LOD) and the calculated Relative Standard Deviation (RSD) of duplicate samples is no greater than 15%.
A widely used extraction technique (Aliquat/MIBK) has been modified and adapted for use with inductively coupled plasma-atomic emission spectrometry for the analysis of geologic materials. A hydrochloric acid-hydrogen peroxide solubilizes metals not tightly bound in the silicate lattice of rocks, soils, and stream sediments. The metals are extracted by a 10% Aliquat 336-diisobutylketone (DIBK) solution as organic halides. The separated organic phase is pneumatically aspirated into a multichannel ICP instrument where the concentrations of the extracted metals (Ag, As, Au, Bi, Cd, Cu, Mo, Pb, Sb, and Zn) are determined simultaneously. It is important to note that this procedure is a partial digestion and depending on an element availability, results may be biased low when compared to other methods of analyses.
| Element | Concentration Range (ppm) | |
|---|---|---|
| Silver, Ag | 0.08 | 400 |
| Arsenic, As | 1.0 | 6,000 |
| Gold, Au | 0.10 | 1,500 |
| Bismuth, Bi | 1.0 | 6,000 |
| Cadmium, Cd | 0.05 | 500 |
| Copper, Cu | 0.05 | 500 |
| Molybdenum, Mo | 0.10 | 900 |
| Lead, Pb | 1.0 | 6,000 |
| Antimony, Sb | 1.0 | 6,000 |
| Zinc, Zn | 0.05 | 500 |
Depending on the type of sample, there may be a significant discrepancy between the proposed value and the laboratory value. This is primarily due to the availability of the metal in the sample. Since this is a partial digestion, those metals tightly bound in highly resistant minerals will not be extracted. Data will be deemed acceptable if recovery for all 10 elements is ±20% on spikes at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 20%.
Total carbon in geologic materials is determined by the use of an automated carbon analyzer. A weighed sample is combusted in an oxygen atmosphere at 1370°C to oxidize carbon to carbon dioxide. Moisture and dust are removed and the carbon dioxide gas is measured by a solid state infrared detector.
The operating range for total carbon is from 0.05% to about 30%.
Data will be deemed acceptable if recovery of total carbon is ±15% at five times the LOD and the calculated percent RSD of duplicate samples is no greater the 15%.
Carbonate carbon in geologic materials is determined as carbon dioxide by coulometric titration. The sample is treated with hot 2N perchloric acid and the evolved carbon dioxide is passed into a cell containing a solution of monoethanolamine. The carbon dioxide, quantitatively absorbed by the monoethanolamine, is coulometrically titrated using platinum and silver/potassium-iodide electrodes. The lower reporting limit is 0.01% carbon dioxide and samples containing up to 50% carbon dioxide may be analyzed. Sample size is adjusted from 0.5 g for the range 0.01 to 5% carbon dioxide, 0.1 g for the range 5 to 10% carbon dioxide, and 0.02 g for greater than 10% carbon dioxide.
Data will be deemed acceptable if recovery for carbonate carbon is ±15% at five times the lower limit of determination and the calculated percent RSD of duplicate samples is no greater than 15%.
A 0.5 gram sample is digested by using a mixture of sulfuric, hydrofluoric, and hydrochloric acids. The solution is titrated with potassium dichromate using sodium diphenylanime sulphonate indicator.
The lower reporting limit is 0.01% FeO.
Data will be deemed acceptable if recovery of FeO is ±15% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 15%.
Essential water is determined by drying the sample for 1 hour at 105±5°C to remove H2O (hydroscopic water). Then the sample is heated at 950°C by using a tube furnace. The H2O+ is absorbed by magnesium perchlorate. From its gain of weight the amount of combined water is calculated.
Non-essential water is determined by drying the sample for 2 hours at 105 ±5°C, from the loss in weight, non-essential water, in percent, is calculated.
The lower reporting limit is 0.05% for both forms of water.
Data will be deemed acceptable if recovery of essential and non-essential water is ±15% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 15%.
Total sulfur is determined by using an automated sulfur analyzer. Approximately 0.25 g of sample is mixed with iron chips and LECOCEL and is heated in a combustion tube in a stream of oxygen at high temperature. Sulfur is oxidized to sulfur dioxide. Moisture and dust are removed and the sulfur dioxide gas is then measured by a CS-244 infrared detector.
The reporting range for total sulfur is from 0.05% to about 35%.
Data will be deemed acceptable if recovery of total sulfur is ±15% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 15%.
Gold is determined in geological materials by Direct Current Plasma (DCP) or atomic absorption spectrophotometry after collection by fire assay. An assay fusion consists of heating a mixture of the finely pulverized sample with about three parts of a flux until the product is molten. One of the ingredients of the flux is a lead compound which is reduced by other constituents of the flux or sample to metallic lead. The latter collects all the gold, together with silver, platinum metals, and small quantities of certain base metals present in the sample and falls to the bottom of the crucible to form a lead button. The gangue of the ore is converted by the flux into a slag sufficiently fluid so that all particles of lead may fall readily through the molten mass. The choice of a suitable flux depends on the character of the ore. The lead button is cupelled to oxidize the lead leaving behind a dore bead containing the precious metals. The dore bead is then transferred to a test tube, dissolved with aqua regia, diluted to a specific volume and determined by DCP or atomic absorption spectrophotometry.
The lower reporting level for a 15 g sample charge is 5 ppb by DCP and atomic absorption.
The upper reporting limit is 10,000 ppb.
Data will be deemed acceptable if recovery of gold is ±20% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 20%.
A 0.1g of sample is digested using a mixture of nitric and hydrochloric acids. Potassium permanganate, sulphuric acid and potassium persulphate are added to the solution, followed by a NaCl-hydroxylamine solution and then the solution is diluted to 25mL. It is mixed thoroughly, allowed to settle and then transferred to the auto sampler rack of the Perkin-Elmer Flow Injection Mercury System, FIMS-100.
The FIMS-100 is a cold-vapor atomic absorption mercury analyzer, which determines the mercury concentration in a solution after it has been liberated as vapor using stannous chloride reducing agent. The absorption of the sample is measured using a mercury lamp at 253.7.
The lower reporting limit of 0.02 ppm mercury in solid-phase samples.
Data will be deemed acceptable if recovery of mercury is ±20% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 20%.
Arsenic and antimony are determined by weighing 0.1 g of sample into a zirconium crucible. Approximately 0.75 g of sodium peroxide is added and mixed. The mixture is heated in a muffle furnace set at 750°C for four minutes. The sample is cooled, then 15 ml of water and 5 ml of concentrated HCl are added. A one ml aliquot is shaken with 0.25 ml of an ascorbic acid KI solution, then diluted to 10 ml with 20% HCl and let to stand overnight. Arsenic and antimony are then measured using hydride generation atomic absorption spectrometry.
The optimum concentration ranges without sample dilution for these elements in various solid phase sample media are: As-0.6 ppm to 20 ppm and Sb-0.6 ppm to 20 ppm.
Data will be deemed acceptable if recovery of As and Sb is ±20% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 20%.
Selenium is determined by weighing 0.25 g of sample into a teflon test tube, adding a mixture of nitric, hydrofluoric and perchloric acids and heating. After the solution is cooled hydrochloric and nitric are added, heated again and cooled. The samples are diluted and analyzed using hydride generation atomic absorption spectrometry.
The expected analytical range for selenium is 0.2 to 4 ppm.
Data for selenium will be deemed acceptable if recovery of that element is ±20% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 20%.
Samples are irradiated together with a standard reference material for one hour in an epithermal flux of approximately 2.5 x 1011 n/cm2/sec. The samples are continuously rotated during the irradiation to ensure a homogeneous irradiation of each sample. Each batch of sample vials is wrapped in polyethylene with a nickel-chrome flux monitor attached to measure the neutron flux exposure to the samples. Four days after the irradiation, the samples are counted for approximately 1,000 seconds (live time) on HpGe detectors. After decay correction, the concentration of tungsten in each sample is computed by comparing the standard concentration, number of counts for tungsten achieved for the standard, and the number of counts achieved for each sample. All spectra are collected an a Canberra multi-channel analyzer linked to a PDP 11/73 computer. The spectra are transferred to the computer for peak search analysis. In the case of tungsten, the number of counts in two energy areas of interest will be determined, 479.5 kev and 685.7 kev.
The lower limit of determination is 0.5 ppm.
Data will be deemed acceptable if recovery of ±20% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 20%.
Tellurium is determined by weighing 0.25 g of sample into a teflon tube, adding a mixture of nitric, hydrofluoric, and perchloric acids and heating. After the solution has cooled, hydrochloric and nitric acids are added, heated again, and cooled. The samples are diluted and analyzed using hydride-generation atomic absorption spectrometry with an autoanalyzer and automated data collection system from Labtronics.
The lower reporting limit for tellurium is 0.1 ppm.
Data for tellurium will be deemed acceptable if recovery of that element is ±20% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 20%.
Thallium is determined by weighing 0.1g of sample into a zirconium crucible. Approximately 0.75g of sodium peroxide is added and mixed. The mixture is heated in a muffle furnace set at 750°C for four minutes. The crucible is cooled and transferred to a vial containig 15 ml of DI water. After the cake disintegrates, 5 ml of concentrated HC1 is added and mixed. A 5 ml aliquot is transferred to a 20 ml test tube, followed by the addition of 1.5 ml of concentrated HNO3. The solution is diluted to 10 ml with DI water and mixed. A volume of 0.5 ml DIBK is added, then capped and shaken for 3 minutes. The organic layer is transferred to an auto sampler and the Thallium concentration is measured by a graphite furnace-atomic absorption spectrophotometer (GFAAS) equipped with a Zeeman background correction.
The lower reporting limit for thallium is 0.1 ppm.
Data for thallium will be deemed acceptable if recovery of that element is ±20% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 15%.
Ten major elements (SiO2; Al2O3; CaO; MgO; Na2O; K2O; Fe2O3; MnO; P2O5; TiO2; and LOI at 925°C) are determined in rocks and minerals by wavelength dispersive X-ray fluorescence spectrometry (WDXRF). The sample is fused with 50/50 lithium metaborate lithium tetraborate flux and the resultant glass disk is introduced into a wavelength dispersive X-ray spectrometer. The disk is irradiated by a Rhodium X-ray tube. X-ray photons emitted by the elements in the sample are counted and concentrations determined using previously prepared calibration curves. In addition to 10 major elements, the method provides a gravimetric loss of ignition.
Calibration curves for each element are derived from a variety (about 40) of international reference materials (NIST, USGS, CANMET, NIM) and a number of synthetic standards to extend the range for certain elements. The standards cover a wide range of geological materials, biased towards igneous rock types. Unusual rock compositions may require a special calibration.
Detection limits for all elements including LOI is 0.01%.
Data will be deemed acceptable if recovery of the major oxides is ±5% at the LOD and the calculated percent RSD of duplicate samples is no greater than 5%.
Fluoride in silicate rocks and minerals is determined by ion selective electrode (ISE). Samples are fused with a mixture of sodium hydroxide and potassium nitrate. The melt is then dissolved in dilute nitric acid, and mixed 1 to 1 with a solution of ammonium acetate prior to measurement by ISE.
Data will be deemed acceptable if recovery of the fluoride is ±15% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 20%.
Sixteen major, minor, and trace elements are determined in geological materials by ICP-AES. The sample is fused with lithium metaborate in a graphite crucible. In house standards and previously analyzed samples are run to monitor the proper digestion procedure. Synthetic standards are used to calibrate the instrument. The solutions are aspirated into the ICP through a high-solids nebulizer and the metal concentrations are measured simultaneously.
| Element | Concentration Range | |
|---|---|---|
| Aluminum, Al | .01% | 15% |
| Barium, Ba | 10 ppm | 10% |
| Calcium, Ca | 01% | 35% |
| Chromium, Cr | .01% | 10% |
| Iron, Fe | .01% | 30% |
| Magnesium, Mg | .01% | 30% |
| Manganese, Mn | .01% | 10% |
| Niobium, Nb | 10 ppm | 10% |
| Phosphorous, P | .01% | 25% |
| Potassium, K | .01% | 25% |
| Silicon, Si | .01% | 30% |
| Sodium, Na | .01% | 30% |
| Strontium, Sr | 10 ppm | 10% |
| Titanium, Ti | .01% | 25% |
| Yttrium, Y | 10 ppm | 10% |
| Zirconium, Zr | 10 ppm | 10% |
Data will be deemed acceptable if they are ±15% at 5 times the lower limit of detection, and the calculated RSD of duplicate samples is no greater than 15%.
Chloride in silicate rocks and minerals is determined by ion selective electrode (ISE). Samples are fused with a mixture of potassium hydroxide and potassium nitrate. The melt is dissolved in dilute nitric acid and then mixed 1 to 1 with a solution of ammonium acetate prior to estimation by ISE.
Data will be deemed acceptable if recovery of the fluoride is ±15% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 20%.
Forty-two major, minor, and trace elements are determined in geological materials by inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS). The sample is decomposed using a mixture of hydrochloric, nitric, perchloric, and hydrofluoric acids at low temperature. An aliquot of the digested sample is aspirated into the ICP-AES and the ICP-MS. The concentrations of the optimal elements from the ICPAES and ICPMS are determined. Calibration on the ICPAES is performed by standardizing with digested rock reference materials and a series of multi-element solution standards. The ICPMS is calibrated with aqueous standards, and internal standards are used to compensate for matrix affects and internal drifts.
| Element | Concentration Range | |
|---|---|---|
| Aluminum, Al | 0.01% | 15% |
| Calcium, Ca | 0.01% | 15% |
| Iron, Fe | 0.01% | 15% |
| Potassium, K | 0.01% | 15% |
| Magnesium, Mg | 0.01% | 15% |
| Sodium, Na | 0.01% | 15% |
| Phosphorous, P | 50 ppm | 1% |
| Titanium, Ti | 0.01% | 15% |
| Silver, Ag | 1 ppm | 10 ppm |
| Arsenic, As | 1 ppm | 1% |
| Barium, Ba | 5 ppm | 1% |
| Beryllium, Be | 0.1 ppm | 100 ppm |
| Bismuth, Bi | 0.04 ppm | 1% |
| Cadmium, Cd | 0.1 ppm | 1% |
| Cerium, Ce | 0.05 ppm | 0.1% |
| Cobalt, Co | 0.1 ppm | 1% |
| Chromium, Cr | 1 ppm | 1% |
| Cesium, Cs | 0.05 ppm | 0.1% |
| Copper, Cu | 0.5 ppm | 1% |
| Gallium, Ga | 0.05 ppm | 500 ppm |
| Indium, In | 0.02 ppm | 0.05% |
| Lanthanum, La | 0.5 ppm | 0.1% |
| Lithium, Li | 1 ppm | 5% |
| Manganese, Mn | 5 ppm | 1% |
| Molybdenum, Mo | 0.05 ppm | 1% |
| Niobium, Nb | 0.1 ppm | 0.1% |
| Nickel, Ni | 0.5 ppm | 1% |
| Lead, Pb | 0.5 ppm | 1% |
| Rubidium, Rb | 0.2 ppm | 1% |
| Sulfur, S | 0.01 % | 5% |
| Antimony, Sb | 0.05 ppm | 1% |
| Scandium, Sc | 0.1 ppm | 0.1% |
| Tin, Sn | 0.1 ppm | 0.1% |
| Strontium, Sr | 0.5 ppm | 1% |
| Tellurium, Te | 0.1 ppm | 0.05% |
| Thallium, Tl | 0.1 ppm | 1% |
| Thorium, Th | 0.2 ppm | 1% |
| Uranium, U | 0.1 ppm | 1% |
| Vanadium, V | 1 ppm | 1% |
| Tungsten, W | 0.1 ppm | 1% |
| Yttrium, Y | 0.1 ppm | 1% |
| Zinc, Zn | 1 ppm | 1% |
Data is deemed acceptable if recovery for all 42 elements is ±15% at five times the Lower Limit of Determination (LOD) and the calculated Relative Standard Deviation (RSD) of duplicate samples is no greater than 15%.
Gold, platinum, and palladium are determined in geological materials by ICPMS after collection by fire assay. An assay ton (30grams) is weighed into a crucible with 150 grams of flux and mixed. One mg of silver nitrate is added and covered with borax, then placed in the furnace for 45 minutes at 1080° C. The melt is poured into a cast iron mold, cooled , and hammered to free the lead button from the slag. The lead button is place on a cupel and heated at 950°C until all the lead is removed. The resulting dore bead is dissolved in a mixture of nitric acid and hydrochloric acid and heated in a water bath. The final solution is adjusted to 10 ml and introduced into the ICPMS. The lower reporting limits are 1 ppb for Au and Pd, and 0.5ppb for Pt. The upper limit for all elements is 10,000 ppb.
Data will be deemed acceptable if recovery of gold, platinum and palladium is ±20% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 20%.
Titanium is determined in geological material using pressed-pellet XRF. A sample weight of at least 5g is required. A pellet is loaded into the holder of the automatic sample changer of a Philips wavelength dispersive x-ray spectrometer. The pellets are run in a vacuum atmoshere employing a rhodium tube. Standard reference materials are inserted with these samples to verify calibration. Calibration is programmed into the instrument and inter-element corrections are applied to necessary analyte elements. This procedure is not suitable for mineralized materials. The presence of percent level concentrations of any element except the usual major rock constituents will have an adverse affect on the calibration. The lower reporting limit is 5 ppm and the upper limit is 10,000 ppm.
Data will be deemed acceptable if recovery of titanium is ±20% at five times the LOD and the calculated percent RSD of duplicate samples is no greater than 20%.
*Two other methods are available upon request: A fused disk-XRF method and a sodium peroxide fusion-ICPAES method. Contact Dave Detra.
Fifty-five major (except Si and Na), rare earth and trace elements are determined in geological materials by inductively coupled plasma-atomic emission spectrometry (ICP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS). The sample is decomposed using a sodium peroxide sinter at 450°C. The resultant cake is leached with water and acidified with nitric acid. After an addition of tartaric acid, aliquots of the digested sample is aspirated into the ICP-AES and the ICP-MS. The concentrations of the optimal elements from the ICPAES and ICPMS are determined. Calibration on the ICPAES is performed by standardizing with digested rock reference materials and a series of multi-element solution standards. The ICPMS is calibrated with aqueous standards, and internal standards are used to compensate for matrix affects and internal drifts.
| Element | Concentration Range | |
|---|---|---|
| Aluminum, Al | 0.01% | 25% |
| Antimony, Sb | 0.1 ppm | 500 ppm |
| Arsenic, As | 30 ppm | |
| Barium, Ba | 0.5 ppm | 1% |
| Beryllium, Be | 5 ppm | 0.25% |
| Bismuth, Bi | 0.1 ppm | 0.1% |
| Cadmium, Cd | 0.2 ppm | 1% |
| Calcium, Ca | 0.01% | 35% |
| Cerium, Ce | 0.1 ppm | 1% |
| Cesium, Cs | 0.1 ppm | 1% |
| Chromium, Cr | 10 ppm | 10% |
| Cobalt, Co | 0.5 ppm | 1% |
| Copper, Cu | 5 ppm | 1% |
| Dysprosium, Dy | 0.05 ppm | 0.1% |
| Erbium, Er | 0.05 ppm | 0.1% |
| Europium, Eu | 0.05 ppm | 0.1% |
| Gadolinium, Gd | 0.05 ppm | 0.1% |
| Gallium, Ga | 1 ppm | 0.1% |
| Germanium, Ge | 1 ppm | 0.1% |
| Hafnium, Hf | 1 ppm | 1% |
| Holium, Ho | 0.05 ppm | 0.1 % |
| Indium, In | 0.2 ppm | 0.1% |
| Iron, Fe | 0.01% | 30% |
| Lanthanum, La | 0.1 ppm | 1% |
| Lead, Pb | 5 ppm | 1% |
| Lithium, Li | 10 ppm | 5% |
| Lutetium, Lu | 0.05 ppm | 0.1% |
| Magnesium, Mg | 0.01% | 30% |
| Manganese, Mn | 10 ppm | 10% |
| Molybdenum, Mo | 2 ppm | 1% |
| Neodymium, Nd | 0.1 ppm | 1 % |
| Nickel, Ni | 5 ppm | 1% |
| Niobium, Nb | 1 ppm | 1% |
| Phosphorous, P | 0.01% | 0.25% |
| Potassium, K | 0.01% | 25% |
| Praesodynium, Pr | 0.05 ppm | 0.1 % |
| Rubidium, Rb | 0.2 ppm | 1% |
| Samarium, Sm | 0.1 ppm | 0.1% |
| Scandium, Sc | 5 ppm | 5% |
| Silver, Ag | 1 ppm | 0.1% |
| Strontium, Sr | 0.1 ppm | 0.1% |
| Tantalum, Ta | 0.5 ppm | 1 % |
| Thallium, Tl | 0.5 ppm | 0.1% |
| Thorium, Th | 0.1 ppm | 0.1% |
| Thulium, Tm | 0.05 ppm | 0.1% |
| Tin, Sn | 1 ppm | 1% |
| Titanium, Ti | 0.01% | 25% |
| Tungsten, W | 1 ppm | 1% |
| Terbium, Tb | 0.05 ppm | 0.1 % |
| Uranium, U | 0.05 ppm | 0.1% |
| Vanadium, V | 5 ppm | 1% |
| Ytterbium, Yb | 0.1 ppm | 0.1 % |
| Yttrium, Y | 0.5 ppm | 1% |
| Zinc, Zn | 5 ppm | 1% |
| Zirconium, Zr | 0.5 ppm | 1% |
Data is deemed acceptable if recovery for all 55 elements is ±15% at five times the Lower Limit of Determination (LOD) and the calculated Relative Standard Deviation (RSD) of duplicate samples is no greater than 15%.
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