Development and Validation of a Sector-Field Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) Method for Analyzing the Diagenesis-Designating Metals in Marine Sediments

摘要

The inductively coupled plasma-mass spectrometry (ICP-MS) technique was applied for the quantification of specific metals in marine sediments following a four-step microwave-assisted digestion protocol. The effects of microwave heating and digesting medium on metal recovery were investigated using lake and river sediment reference materials to minimize the deviations from certified values. Increasing the temperature and time variables improves the accuracy of the ICPMS measurements so that an optimized acid-digestion protocol enables the determination of heavy metals in sediments with relative errors better than 10%. The developed method was applied to measure longitudinal metal distribution in sediments collected from the continental shelf of the East Siberian Sea in the range from 50 to 600 km. Minima in the content of redox sensitive elements such as Mn, Mo, V, U, and Sb at distances from 200 to 300 m to the coast are most likely related to diagenetic processes such as sulfide reduction in the upper part of the sediment. In addition, the quality of sediments under consideration was assessed in terms of the average and maximum concentrations of heavy metals that may contaminate the bottom seawater. The developed method can be recommended as a standard tool for accurate and precise sediment analysis with important geochemical and environmental implications.