Quantification of chloride in concrete samples using LA-ICP-MS

Inspection of the chloride content in concrete samples is an important factor for determination and planning of maintenance measures. The standard method given by European legislative for chloride determination is the titrimetric Volhard method. However, it requires significant experimental effort, and knowledge about the cement content in the concrete is required. In this work, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is proposed as an alternative method to the commonly used wet-chemical approach. LA-ICP-MS allows analysis of drilled core concrete samples with increased depth resolution, minimal workload for sample preparation, and fast analysis time. Furthermore, exploiting the multi-elemental capabilities of ICP-MS, an in-depth analysis of the sample composition, allowing a differentiation between cement phase and aggregates is feasible. Using this information, selective determination of chloride in the cement phase becomes possible, which helps to increase the reliability of the determined chloride concentrations.