RESUMEN
Total reflection X-ray spectrometry is an instrumental technique based on X-ray fluorescence, which offers detection limits low enough to quantify trace element concentrations with negligible interference from matrix components. The technique is well established in material sciences and now reaches out to extended applications in life sciences and pharmaceutical quality control. In our study we focused on possible applications for the quantification of gold and platinum containing active ingredients in trace concentrations (ppb range) in a matrix of biological origin (cell suspensions). General aspects of sample preparation as well as selected important method performance parameters (precision, recovery rates) were investigated. Overall, TXRF represents an useful option to quantify metals in ppb concentrations with acceptable precision and recovery.