COMPARISON OF ACID DIGESTION TECHNIQUES TO DETERMINE HEAVY METALS IN SEDIMENT AND SOIL SAMPLES

Abstract

Four acid digestion procedures were applied to certified samples to offer a proper method for determination of Cr, Cu, Pb and Zn in soils and sediments. EPA’s Acid Digestion Procedure 3050B and three low pressure power microwave heating programmes modified in this study were tested by using two standard materials; Estuarine Sediment-1646A and San Joaquin Soil-2709. Short digestion time, less acid consumption, and high extraction efficiency were noted as the advantages of microwave digestion procedures. According to the results, San Joaquin Soil was efficiently extracted with the second microwave heating programme named as P2 (84.4% Cr, 96.9%Cu, 102.3% Pb, 90.1% Zn)  where Estuarine Sediment gave the most accurate results (99.8% Cr, 103.9% Cu, 97.4% Pb, 96.3% Zn ) with the third extraction procedure (P3).

Keywords: acid digestion, heavy metal,  microwave extraction, sediment, soil

Keywords

• Acid digestion, Heavy metal, Microwave extraction, Sediment, Soil

References

1. Sastre, S., Sahuquillo, A., Vidal, M., Rauret, G., “Determination of Cd, Cu, Pb and Zn in environmental samples: microwave-assisted total digestion versus aqua regia and nitric acid extraction”, Anal. Chim. Acta, 462:59-72 (2002).
2. Friberg, L., Nordberg, G.F., Vouk, V., “Handbook on the Toxicology of Metals”, Elsevier, Amsterdam, 18 (1986).
3. Sandroni, V., Smith, C.M.M, Donovan, A., “Microwave digestion of sediment, soils and urban particulate matter for trace metal analysis”, Talanta, :715-723 (2003).
4. Berghoff-Tetra., “Last Improvements in Microwave Digestion Systems”, Izmir, Turkey (2004).
5. Dean, J.R., “Methods for Environmental Trace Analysis”, John Wiley&Sons Ltd, London, 51-52 (2003).
6. Cook, J.M., Gardner, M.J., Griffiths A.H., Jessep M.A., Ravenscroft J.E., Yates R., “The comparibility of sample digestion techniques for the determination of metals in sediments” Mar. Poll. Bull., 34(8):637-644 (1997).
7. Lo, J.M., Sakamoto, H., “Comparison of acid combinations in microwave-assisted digestion of marine sediments for heavy metal analysis”, Anal. Sci. , 21:1181-1184 (2005).
8. Sandroni, S., Smith, C.M., “Microwave digestion of sludge, soil and sediment samples for metal analysis by inductively coupled plasma–atomic emission spectrometry”, Anal. Chim. Acta, 468(2):335-344 (2002).

9. USEPA, “Method 3050B Acid digestion of sediments, sludges and soils”, Revision 2,
10. Environmental Protection Agency, Washington, USA 3-5 (1996).
11. Questron Technologies Corp.,“ MicroPrep Q20 Microwave Digestion System, Operating Manual”, Ontario, Canada (2005).
12. NIST, “Certificate of Analysis, Standard Reference Material 2709- San Joaquin Soil,” https://srmors.nist.gov/view_cert.cfm?srm=2709 (2003).
13. NIST, “Certificate of Analysis, Standard Reference Material 1646a-Estuarine Sediment”, https://srmors.nist.gov/view_detail.cfm?srm=1646 A (2004).