Quality of the Trace Element Analysis: Sample Preparation Steps

Current status of elemental analysis performed using atomic spectroscopy techniques is to reach the best results in the shortest time and with minimal contamination and reagent consumption. Various spectroscopic methods such as flameand graphite furnace atomic absorption spectrometry (Fand GF-AAS), inductively coupled plasma optical emission spectrometry (ICP-OES) or inductively coupled plasma mass spectrometry (ICP-MS) have been used for many years for determination of elements, since they met needs required in analytical applications. Constant progress in detector technology can still been observed, e.g. in terms of lowering quantification limits. Despite these advantages, quality of results does not follow the same tendency and sample preparation is recognized to be a critical point and the most important error source in modern analytical method development. This is especially true for solid samples that have to be brought into solution before measurements. It is dictated by instrumentation requirements dedicated to analysis of liquid samples. Determination of analyte concentrations in solid materials is not an easy task and several factors should be considered in order to minimize uncertainty in sample preparation and to achieve real objectives of analysis. It includes sample type and its matrix composition responsible mainly for the degree of difficulties during sample preparation and analyte determination. Therefore, the good choice of sample treatment and confidence of its application become a key ensuring to obtain reliable results.