Fast and low sample consuming quantification of manganese in cell nutrient solutions by flow injection ICP-QMS

Inductively coupled plasma mass spectrometry with quadrupole mass analyzers (ICP-QMS) is one of the most powerful analytical techniques due to its superb limits of detection and the fast, quasi simultaneous quantification of different elements in one single run. However, sample consumption is typically too large for use in biological studies and spectral as well as non-spectral interferences are often hard to compensate for. Hence, a flow injection (FIA) approach for quantification of manganese (Mn) in biologically relevant cell nutrient solutions was developed, extending the sample throughput and versatility of a common system. The investigated cell nutrient solutions are, for example, used in in vitro models of the blood-brain and the blood-liquor barrier and represent a complex matrix, while Mn is of interest due to its potential neurotoxic effects, but shows several challenges in ICP-QMS analysis. Therefore, the aim of the study was not only to devise a system as simple as possible, but also to have a tool allowing the measurement of several hundreds of samples within a short period of time. Furthermore, statistical data treatment was used to evaluate the need for matrix matching and internal standardization for the four different solutions. The calculated lowest detection limits (LODs) were in the low μg L(-1) range due to successful use of a collision/reaction cell, while only 11 μL of sample volume was needed per injection by means of a segment sample loop filling. The analysis of a certified reference material further confirmed the suitability of this approach in biological studies.