Determination of Trace Elements in Seawater using ICP-MS Application Note · PlasmaQuant MS

Introduction

The analysis of trace elements in seawater is one of the most challenging analytical tasks in the field of environmental monitoring – the trace element concentrations are usually quite low, often in the low ng/L range, and the seawater matrix causes interferences from its high dissolved salt content (3.5%
m/v).

For ICP-MS, the seawater matrix is challenging physically and chemically. Continuous nebulization leads to salt deposition on the sampler and skimmer cones, resulting in a loss in sensitivity and poor long-term stability. The chemical composition of the sea water matrix causes polyatomic ion interferences and non-spectroscopic interferences, particularly for the determination of the first-row
transition elements.

To overcome these analytical challenges, a sample dilution by a factor of 10 or 20 is the first choice to obtain good signal stability for each sample run but also for a series of samples. A range of different methods such as solvent extraction [1,2], coprecipitation [3–6], and chelating resin adsorption [7,8] have been developed for matrix removal and preconcentration of trace metals in seawater. Among
those, the chelating resin adsorption technique is the most promising approach, as it does not require harmful organic solvents and has a low risk of contamination.

This application note describes a method for the reliable determination of multiple elements in seawaters on a PlasmaQuant® MS, ICP-MS.