Application of microwave–assisted digestion to trace heavy metal determination in sea sediment sample

Abstract

The main goal of this study is to develop an efficient microwave digestion method for the determination of Pb, Cu, Cr, Co and Zn elements from a sea sediment sample. Microwave acid digestion techniques were investigated to obtain a simple, rapid and safe method for the determination of five trace elements in sediment. Sediment sample was airdried, grinded, sieved (& #8804; 100 mesh) and subjected to digestion. The digests were subsequently analyzed for metal content by atomic absorption spectrophotometry (AAS). Various combinations and volumes of hydrofluoric, nitric and hydrochloric acids were evaluated for the microwave acid digestion efficiency. Certified reference material (GSP-2, geological certified reference material) was used in the comparison of these digestion protocols. The microwave acid digestion with a mixture of 4 mL of 65% $HNO _3$, 1 mL of 37% HCl, 4 mL of 40% HF produced the fastest, safest and accurate analytical results with a recovery of 75& #8211; 92% and a precision better than 5% in most cases. Sea sediment sample whose sampling location was the deep sea discharge of the paper plant in Dalaman, Turkey, was analyzed.