Multi-element Analysis Of Soils And Sediments By Wavelength-dispersive X-ray Fluorescence Spectrometry

Soil and sediment reference materials were used to calibrate and evaluate an analytical method for the determination of major (Si, Al, Fe, Mg, Ca, Na, K, Mn, P, Ti) and trace elements (As, Ba, Cd, Co, Cr, Cu, Ga, Mo, Mb, Ni, Pb, Rb, S, Sb, Sn, Sr, Th, U, V, Y, Zn, Zr) by sequential wavelength X-ray fluorescence spectrometry. Samples were prepared as pressed pellets and analysis was done with a total measuring time of thirty minutes per sample. Special attention was given to the selection of the thirty reference materials used for calibration of the spectrometer. Another set of eleven RM (reference materials) was analyzed for the evaluation of accuracy. Detection limits for trace elements (1-2 mg kg-1) are adequate both for geochemical and environmental purposes, except for Cd and Sb. Accuracy for trace elements falls within the expected interval of certified or recommended values in most cases, but for some major elements, like SiO2, some results showed discrepancies, evidencing difficulties associated with the determination of light elements in complex matrices. But when quality criteria proposed by mapping programs are applied to the results, their requirements are fulfilled. Both instrumental precision, obtained by twelve sample replicate analyses, and analytical precision, considering also sub-sampling and pellet preparation, lie between the limits of the Horwitz expression, except at concentrations close to the detection limits.212936Elsenbroek, J.H., Instrumentation and analytical technique for the analysis of regional geochemical samples used at the South-African Council for Geoscience - An overview (1995) Analyst, 120, pp. 1535-1541Civici, N., Van Grieken, R., Energy-dispersive X-ray flourescence analysis in geochemical mapping (1997) X-Ray Spectrom, 26, pp. 147-152Swennen, R., Van der Sluys, J., Zn, Pb, Cu, Cd and As distribution patterns in overbank and medium order stream sediment samples: Their use in environmental geochemistry and in exploration of base metal ore bodies in heavily polluted areas (1998) J Geochem Explor, 65, pp. 27-45Szaloki, I., Somogyi, A., Braun, M., Tóth, A., Investigation of geochemical composition of lake sediments using ED-XRF and ICP-AES techniques (1999) X-Ray Spectrom, 28, pp. 399-405Lombard, M., de Bruin, D., Elsenbroek, J.H., High-density regional geochemical mapping of soils and stream sediments South-African (1999) J Geochem Explor, 66, pp. 145-149Swennen, R., Van Der Sluys, J., Hindel, R., Brusselmans, A., Geochemistry of overbank and high-order stream sediments in Belgium and Luxembourg: A way to assess environmental pollution (1998) J Geochem Explor, 62, pp. 67-69dos Anjos, M.J., Lopes, R.T., de Jesus, E.F.O., Assis, J.T., Cesareo, R., Barradas, C.A.A., Quantitative analysis of metals in soil using X-ray flourescence (2000) Spectrochim Acta, 55 (PART B), pp. 1189-1194Aisueva, T.S., Gunicheva, T.N., Nondestructive X-ray flourescence analysis of soil, silts, river and bottom sediments (1999) J Anal Chem, 54, pp. 1222-1227Alov, N.V., Bulgachev, R.V., Oskolok, K.V., Features of technogenic metal pollution of roadside soil according to X-ray flourescence monitoring data (2001) J Soils and Sediments, 1, pp. 164-167Kane, J.S., Quality control and reference sample data bases (1991) Geostand Newsl, 15, pp. 33-42Ma, G., Li, G., Application of X-ray flourescence spectrometry to the analysis of geochemical prospecting samples in China (1989) X-Ray Spectrom, 8, pp. 199-205Xuejing, X., Analytical requirements in international geochemical mapping (1995) Analyst, 120, pp. 1497-1504Casarini, D.C.P., (2000) Seminário internacional sobre qualidade de solos, águas subterrâneas: Proposta de valores orientadores para o Estado de São Paulo, 2. , São Paulo SMA/CETESB, 165 ppCanadian sediment quality guidelines for the protection of aquatic life: Summary tables (1999) Canadian Environmental Quality Guidelines, , http://www.ec.gc.ca/ceqg-rcqe/sedtble.PDF, Canadian Council of Ministers of The Environment (CCME), Canada, available inKane, J.S., Homogeneity of reference materials (1997) Analyst, 122, pp. 1289-1292Gunicheva, T.N., Aisueva, T.S., Afonin, V.P., Nondestructive X-ray flourescence analysis of soils and friable and marine sediments (1995) X-Ray Spectrom, 24, pp. 187-192Darnley, A.G., Björklund, A., Bolviken, B., Gustavsson, N., Koval, P.V., Plant, J.A., Steenfelt, A., Xuejing, X., (1995) A Global Geochemical Database for Environmental and Resource Management: Recommendations for International Geochemical Mapping - Final Report of IGCP Project 259, , Paris: United Nation Educational, Scientific and Cultural Organization (UNESCO), 122 ppHorwitz, W., Albert, R., Precision in analytical measurements: Expected values and consequences in geochemical analysis (1995) Fresenius J Anal Chem, 35, pp. 507-513Thompson, M., Potts, P.J., Webb, P.C., GeoPT1. International proficiency test for analytical geochemistry laboratories - Report on round 1 (July 1996) (1996) Geostand Newsl, 20, pp. 295-32