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Inductively Coupled Plasma-Atomic Emission Spectrometry/Acid Dissolution Methods

Methods

• Analysis of 40 Elements by ICP-AES (USGS and XRAL Laboratories). Forty major, minor, and trace elements were determined by ICP-AES. Sample aliquants of 200 mg are decomposed using a mixture of hydrochloric, nitric, perchloric, and hydrofluoric acids at low temperature. The digested samples are 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. Analytical data for an experimental run are deemed acceptable based on results determined for two in-house quality-control standards: recovery for all elements present at >5 times the detection limit must be within 15% of the certified value, and the calculated relative standard deviation of duplicate samples is no greater than 15%. For additional information, see Briggs (1996, 2002).

  Reporting limits for 40 elements measured by ICP-AES at the USGS and XRAL laboratories.

  Element	Units	Lower limit	Upper limit		Element	Units	Lower limit	Upper limit
  Aluminum	%	0.005	50		Holmium	ppm	4	5 000
  Calcium	%	0.005	50		Lanthanum	ppm	2	50 000
  Iron	%	0.02	25		Lead	ppm	4	50 000
  Potassium	%	0.01	50		Lithium	ppm	2	50 000
  Magnesium	%	0.005	5		Manganese	ppm	4	50 000
  Sodium	%	0.005	50		Molybdenum	ppm	2	50 000
  Phosphorus	%	0.005	50		Niobium	ppm	4	50 000
  Titanium	%	0.005	25		Neodymium	ppm	9	50 000
  Arsenic	ppm	10	50 000		Nickel	ppm	3	50 000
  Barium	ppm	1	35 000		Scandium	ppm	2	50 000
  Beryllium	ppm	1	5 000		Silver	ppm	2	10 000
  Bismuth	ppm	10	50 000		Strontium	ppm	2	15 000
  Cadmium	ppm	2	25 000		Tantalum	ppm	40	50 000
  Cerium	ppm	5	50 000		Tin	ppm	5	50 000
  Cobalt	ppm	2	25 000		Thorium	ppm	6	50 000
  Chromium	ppm	2	25 000		Uranium	ppm	100	100 000
  Copper	ppm	2	15 000		Vanadium	ppm	2	30 000
  Europium	ppm	2	5 000		Yttrium	ppm	2	25 000
  Gallium	ppm	4	50 000		Ytterbium	ppm	1	5 000
  Gold	ppm	8	50 000		Zinc	ppm	2	15 000

• Analysis of 44 Elements by ICP-AES (ACME Laboratories). This method is discussed in Folger (2000), who provides details about detection limits, although the exact differences between the methodology used by ACME and that discussed above for the USGS and XRAL laboratories is not well described.  In addition to the 40 elements listed above, Cs, Rb, Sb, and Zr are determined.

Data analysis

Distribution maps Element QA/QC Conter- minous Alaska Hawai`i Al (wt%) In progress Ca (wt%) In progress Fe (wt%) In progress K (wt%) In progress Mg (wt%) In progress Na (wt%) In progress P (wt%) In progress Ti (wt%) In progress Sb (ppm) In progress no data no data As (ppm) In progress Ba (ppm) In progress Be (ppm) In progress Bi (ppm) In progress no data Cd (ppm) In progress no data Ce (ppm) In progress Co (ppm) In progress Cr (ppm) In progress Cs (ppm) In progress no data no data Cu (ppm) In progress Eu (ppm) In progress Ga (ppm) In progress Au (ppm) In progress no data

Distribution maps Element QA/QC Conter- minous Alaska Hawai`i Ho (ppm) In progress no data La (ppm) In progress Pb (ppm) In progress Li (ppm) In progress Mn (ppm) In progress Mo (ppm) In progress Nb (ppm) In progress Nd (ppm) In progress Ni (ppm) In progress Rb (ppm) In progress no data no data Sc (ppm) In progress Ag (ppm) In progress no data Sr (ppm) In progress Ta (ppm) In progress no data Sn (ppm) In progress no data Th (ppm) In progress U (ppm) In progress no data no data V (ppm) In progress Y (ppm) In progress Yb (ppm) In progress Zn (ppm) In progress Zr (ppm) In progress no data no data

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U.S. Department of the Interior, U.S. Geological Survey
This page is part of U.S. Geological Survey Open-File Report 2004-1001
URL: http://www-tin.er.usgs.gov/geochem/doc/icp40.htm
Maintained by Jeff Grossman
Last modified: 15:03:11 Tue 06 Jan 2004
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