Determination of Major and Minor Elements in HF-Digested Soil Samples using an Agilent 5110 ICP-OES

Introduction

The accurate elemental analysis of soil and rock samples can depend on reliable and reproducible sample preparation methods. If silicate-based minerals are likely to be present in the samples, laboratories must use hydrofluoric (HF) acid during sample preparation to ensure complete sample dissolution. Regulated methods, such as US EPA 3052, require the use of HF to achieve total sample decomposition (1). Standard glass or quartz sample introduction systems are not suitable for handling HF acid digests as any free HF attacks and degrades the glass and quartz components. To prevent degradation of glassware, the analyst must neutralize any residual HF before analysis, which reduces workflow efficiency and introduces a potential source of contamination. For this reason, laboratories that routinely analyze HF sample digests by atomic spectroscopy use inert sample introduction components which allow the digests to be run directly, without requiring a neutralization step.