METHOD DEVELOPMENT FOR THE DETERMINATION OF TIN IN A MARINE SEDIMENT AND A PRELIMINARY STUDY OF TIN DISTRIBUTION FROM LA PAZ, B.C.S., MEXICO

J.L. Gardea-Torresdey, S. Martinez-Gonzalez and K.H. Pannell

Department of Chemistry, University of Texas at El Paso, El Paso, TX 79968, 915-747-5359, FAX 915-747-5748


ABSTRACT

Organotin compounds are used as fungicides and antifouling agents, which are incorporated into paints for use in sea vessels. These compounds have been found to be a threat to the environment. Method development for the determination of total tin in marine sediments by Zeeman GFAAS was studied. The optimum pyrolysis and atomization temperatures for tin analysis were 1100C and 2300C, respectively. When different matrix modifiers were evaluated, a mixture of NH4H2PO4 /Mg(NO3)2 and Mg(NO3)2 alone produced the optimum tin signal. No significant effect on the tin signal was observed when using HNO3 as a diluent. The extraction of total tin from marine sediments was best performed by sample digestion with 6 M HCl and diluting the sample extracts with 1% HNO3. Finally, the tin analytical and extraction method developed in our investigation was used to determine tin content in marine sediments from La Paz, Baja California Sur, Mexico. Tin concentrations in La Paz Bay area ranged from 320 to 5570 g Sn/Kg of sediment (dry-weight).

KEY WORDS

tin, organotin, Zeeman GFAAS, marine sediment analysis, tin determination

This paper is from the Proceedings of the 10th Annual Conference on Hazardous Waste Research 1995, published in hard copy and on the Web by the Great Plains/Rocky Mountain Hazardous Substance Research Center.


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