Aluminium Normalization of Heavy-Metal data from Estuarine and Coastal Sediments of the Gulf of Thailand

Abstract

Sediment samples were collected from 20 stations along the coastal line of the Gulf of Thailand. Trace metal concentrations were then determined using an atomic absorption spectrophotometer for Al, Fe, Mn, while Zn, Cr, Cu, Pb, Cd, Ag,and Ni were analysed using an inductively coupled plasma atomic emission spectrophotbmeter. Each metal was then normalized using Al as the- reference element. Two of the metals, namely Zn and Cr were shown to covary strongly with Al, with correlation coefficient (r2) ranging between 0.88-0.90. Four otler metals also showed positive linear correlations with the reference element, with r ' values of 0.69 for Cu, 0.60 for Fe, 0.52 for Pb, and 0.50 for Cd. The last 3 metals, Mn, Ag, 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 coastal sediments of the Gulf of Thailand and the adjacent area such as Straits of Melaka. Although studies on heavy metals in the coastal waters of Thailand have existed for