|The determination of suspended metals in coastal waters by different sampling and processing techniques (filtration, centrifugation)|
Duinker, J.C.; Nolting, R.F.; van der Sloot, H.A. (1979). The determination of suspended metals in coastal waters by different sampling and processing techniques (filtration, centrifugation). Neth. J. Sea Res. 13(2): 282-297
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579, more
|Authors|| || Top |
- Duinker, J.C.
- Nolting, R.F.
- van der Sloot, H.A.
The concentrations, on a sediment weight basis, of several metals in coatal suspended matter show a marked dependence on the amount of particulate matter per litre. The effects of filtration and centrifugation are compared. The resulting data are interpreted in terms of varying contributions of larger and denser bottom derived particles with higher concentrations of K, Fe, Mn and Al and of smaller and less dense, continuously suspended particles with higher concentrations of Cu, Cd, Pb and Zn. No dependence on size or density was found for Cr, Si, Mg and Ca.Filtration results in higher concentrations of Cu, Cd, Pb and Zn. For the other elements, centrifugation results in concentrations that are at least similar to those in particulates obtained by filtration, or even larger for elements with relatively large difference between the concentrations in the different fractions, such as K. Leaching particulates, obtained by filtration and centrifugation, with 0,1 N HCl leads to differences in the leached fractions for Cd, Cr, K and Mg at lower suspended loads, and for Fe at higher loads, while no differences are observed for Cu, Pb, Zn, Si, Mn, Al and Ca. Accurate particulate metal concentration data were obtained by measuring in each individual sample, the amount of both metal and particulate matter. This results in more accurate data than can be obtained by measuring each of the properties in separate samples. Another source of error is eliminated by analyzing the entire content of a sampler in stead of part of it, because of sample inhomogeneity introduced by settling of particles in the sampler. In order to get accurate sediment weight data at low suspended matter concentrations, sea salt was removed from the particulate matter by a rinsing procedure with distilled water. No loss of the metals investigated (Cu, Cd, Zn, Cr, Si, Fe, Mn, and Al) was evident with a possible exception for Cd.