FTIR (Fourier transform infrared), PIXE (proton induced X-ray emission), EBS (elastic backscattering spectroscopy) are applicable to trace element analysis in biological samples. Recently, we have applied two of these three techniques for investigation of trace element content in renal stones . In this study the FTIR technique was used for chemical composition (phase structure) determination and choice of standards. The PIXE technique was applied for determination of stone elemental composition. Using the EBS technique, we were able to make corrections taking into account beam energy depth dependence and the X-ray attenuation effect. Such an effect is particularly significant for light elements. Combining the three techniques mentioned above it was possible to form a procedure for trace element determination in thick biological targets.