Use of aluminium to normalize heavy-metal data from estuarine and coastal sediments of Straits of Melaka

Abstract

Sediment samples were collected from 24 stations along the Malaysian coast of the Straits of Melaka. Trace-metal concentrations were then determined using an atomic absorption spectrophotometer for Al, Fe and Mn, while Cd, Cr, Ag, Au, Cu, Zn, As, Pb, and Sn were analysed using an induced-couple plasma/mass spectrophotometer. Each metal was then normalized using Al as the reference element. Five of the metals, namely Cr, Fe, Zn, Cu, and Pb were shown to covary strongly with Al, with correlation coefficient (r 2) ranging between 0.86–0.93. Three other metals also showed positive linear correlations with the reference element, with r 2 values of 0.72 for Cd, 0.67 for As, and a mere 0.39 for Sn. The last 4 metals, Ag, Au, Mn, and Ni did not covary with Al. On the whole, it was concluded that for most cases, Al can be used to normalize granular variability in trace-metal analyses of the sediments of the Malaysian coast of the Straits of Melaka.