Application of high-temperature fusion for analysis of major and trace elements in marine sediment trap samples

Abstract

Multielemental information is important for a broad range of ocean biogeochemical studies, yet the quantity of sample material available for analysis is often extremely limited. Here we describe a simple, rapid, and accurate method for multielemental analyses of oceanic sediment trap material. This method involves high-temperature fusion using a lithium metaborate flux for sample digestion and elemental quantification using high-resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). Each analysis consumes only 1 to 2 mg of sample material yet enables simultaneous measurements of 18 elements (Mg, Al, Si, P, Ca, Sc, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Sr, Cd, Ba, and Pb) with accuracy of > 90% for most elements. The fusion method introduces minimal contamination when appropriate sample handling and procedural precautions are employed. Elemental quantification of samples prepared for ICP-MS analysis using fusion agrees well with those prepared using acid digestion. Additionally, the fusion method has several advantages over acid digestion. No highly toxic reagents like hydrofluoric acid are used. Refractory mineral dissolution is more complete. Si, Ca, and other trace elements can be analyzed without potential losses due to coprecipitation with CaF2. The simplicity and reproducibility of the procedure makes it especially suitable for routine, ongoing analyses of oceanic particulate materials.