Synchrotron radiation induced TXRF

Synchrotron radiation excited total reflection X-ray fluorescence analysis is a very promising technique for ultra trace analysis of samples with small sample amount available. Chemical speciation can also be performed at trace levels.The use of synchrotron radiation (SR) as an excitation source for total reflection X-ray fluorescence analysis (TXRF) offers several advantages over X-ray tube excitation.

Detection limits in the fg range can be achieved with efficient excitation for low Z as well as high Z elements due to the features of synchrotron radiation and in particular the high brilliance in a wide spectral range and the linear polarization in the orbital plane. SR-TXRF is especially interesting for samples where only small sample masses are available.

Lowest detection limits are typically achieved using multilayer monochromators since they exhibit a bandwidth of about 0.01 ΔE/E. Monochromators with smaller bandwidth like perfect crystals, reduce the intensity, but allow X-ray absorption spectroscopy (XAS) measurements in fluorescence mode for speciation and chemical characterisation at trace levels.

SR-TXRF is performed at various synchrotron radiation facilities. An historical overview is presented and recent setups and applications as well as some critical aspects are reviewed.