Inductively coupled plasma mass reference materials

Laser based mass spectrometric methods, such as laser ionization (LIMS) and laser ablation in combination with inductively coupled plasma mass spectrometry (LA-ICP-MS) are powerful analytical techniques for survey analysis of solid substances. To realize the analytical performances methods for the direct trace analysis of synthetic and natural crystals modification of a traditional analytical technique was necessary and suitable standard reference materials (SRM) were required. Recent developments allowed extending the range of analytical applications of LIMS and LA-ICP-MS will be presented and discussed. For example ... 

Moens L, Verreft P, Boonen S, Vanhaecke F and Dams R (1995) Solid sampling electrothermal vaporization for sample introduction in inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. Spectrochim Acta 508 463-475. Mooijman KA, In t Veld PH, Hoekstra JA, Heisterkamp SH, Havelaar AH, Notermans SHW, Roberts D, Griepink B, Maier E (1992) Development of Microbiological Reference Materials. European Commission Report EUR 14375 EN, Community Bureau of Reference, Brussels. 

Zheng, J., Kosmus, W., Pichler-Semmelrock, F., and Kock, M., Arsenic speci-ation in human urine reference materials using high-performance liquid chromatography with inductively coupled plasma mass spectrometric detection, /. Trace Elements Med. Biol., 13, 150, 1999. 

Goossens J, Moens L, Dams R. Inductively coupled plasma mass spectrometric determination of heavy metals in soil and sludge candidate reference materials. Anal. Chim. Acta 1995 304 307-315. 

Hollocher, K. and Ruiz, J. (1995). Major and trace-element determinations on NIST glass standard reference material-611, material-612, material-614, and material-1834 by inductively-coupled plasma-mass spectrometry. Geostandards Newsletter 19 27-34. 

The primary and immediate need is for a trace metal reference material, but a certified reference material would provide even greater benefits. A technique based on isotope dilution with detection by inductively-coupled plasma mass spectrometry (ICP-MS) (Wu and Boyle, 1998) most clearly meets the traceability criteria required for a certified reference material. Although useful for iron and several other metals, isotope dilution is not possible for monoisotopic elements like cobalt, so other techniques must also be used. Indeed, it is advisable that several techniques be used to certify a trace metal reference material. 

The major anions and cations in seawater have a significant influence on most analytical protocols used to determine trace metals at low concentrations, so production of reference materials in seawater is absolutely essential. The major ions interfere strongly with metal analysis using graphite furnace atomic absorption spectroscopy (GFAAS) and inductively coupled plasma mass spectroscopy (ICP-MS) and must be eliminated. Consequently, preconcentration techniques used to lower detection limits must also exclude these elements. Techniques based on solvent extraction of hydrophobic chelates and column preconcentration using Chelex 100 achieve these objectives and have been widely used with GFAAS. 

L. Moberg, K. Pettersson, I. Gustavsson and B. Karlberg, Determination of cadmium in fly ash and metal allow reference materials by inductively coupled plasma mass spectrometry and chemometrics, J. Anal. At. Spectrom., 14(7), 1999, 1055-1059. 

If the reference materials are pure substances and can be specified on the microscopic level, then they represent the unit amount of substance. Because there are no absolute pure substances the representation is in all cases an approximation. The degree of approximation is given by the accuracy of the contents of the main component. In case of pure elements, e.g. metals Fe, Cu, Zn the determination of the main component by coulometry is limited by an uncertainty of 0.01%. The determination of all impurities needs completeness and requires a great deal of analytical equipment. However, a combination of inductively coupled plasma-mass spectrometry (ICP-MS), atomic absorption spectrometry (AAS) and isotope dilution mass spectrometry (ID-MS) covering all elements of the periodic table allows a decrease of total uncertainty to 0.0032% (Cu, see Fig. 8). 

Hirata, T. (1996) Lead isotopic analyses of NIST standard reference materials using multiple collector inductively coupled plasma mass spectrometry with a modified external correction method for mass discrimination effect. Analyst 121, 1407-1411. 

Chang Joon Park, Jung Kee Suh, Kwang Woo Lee, Sang Hak Lee, Determination of Cd, Cu, Zn and Pb in rice flour reference materials by isotope dilution inductively coupled plasma mass spectrometry, Anal. Sci., 13 (1997), 429-432. 

R. Wahlen, S. McSheehy, C. Scriver, Z. Mester, Arsenic speciation in marine certified reference materials. Part 2. The quantification of water-soluble arsenic species by high-performance liquid chromatography - inductively coupled plasma mass spectrometry, J. Anal. Atom. Spectrom., 19 (2004), 876-882. 

J. K. Friel, C. S. Skinner, S. E. Jackson, H. P. Longerich, Analysis of biological reference materials prepared by microwave dissolution using inductively coupled plasma mass spetrometry, Analyst, 115 (1990), 269-273. 

Van Straeten M. and Gijbels R. (1995) Determination of the scandium content of high-purity titanium using inductively coupled plasma mass spectrometry and glow discharge mass spectrometry as part of its certification as a reference material, J Anal At Spectrom 10 849-852. 

Ivanova J., Korhammer S., Djingova R., Heidenreich H., Markert B., 2001, Determination of lanthanoids and some heavy and toxic elements in plant certified reference materials by inductively coupled plasma mass spectrometry, Spectrochim. Acta B, 56, 3-12. 

Beary ES, Paulsen PJ and Fassett JD (1994) Sample preparation approaches for isotope dilution inductively coupled plasma mass spectrometric certification of reference materials. J Anal Atom Spectrosc 9 1363-1369. 

Larsen EH and Ludwigsen MB (1997) Determination of iodine in food-related certified reference materials using wet ashing and detection by inductively coupled plasma mass spectrometry. J Anal Atom Spectrom 12 435-439. 

Vanhoe H, Vandecasteele C, Veesieck J and Dams R (1989) Determination of trace elements in a human serum reference material by inductively coupled plasma mass spectrometry. Mikrochim Acta 3 373-379. 

Beauchemin, D., McLaren, J.W., Willie, S.N. and Berman, S.S. (1988b) Determination of trace metals in marine biological reference materials by inductively coupled plasma mass spectroscopy. Anal. Chem., 60, 687-691. 

Friel, J.K. Skinner, C.S., Jackson, S.E., and Longerich, H.P. (1990) Analysis of biological reference materials, prepared by microwave dissolution, using inductively coupled plasma mass spectrometry. Analyst, 115, 269-273. 

McLaren, J.W., Methven, B.A.J., Lam, J.W.H., Berman, S.S., 1995. The use of inductively coupled plasma mass spectrometry in the production of environmental certified reference materials. Microchim. Acta 119,287-295. 

Feng, X., Wu, S., Wharmby, A., and Wittmeier, A., "Microwave Digestion of Plant and Grain Standard Reference Materials in Nitric and Hydrofluoric Acids for Multi-Elemental Determination by Inductively Coupled Plasma Mass Spectrometry," J. Anal. At. Spectrom., 14,1999, pp. 939-946. 

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