Total-reflection X-ray fluorescence moving towards nanoanalysis: a survey

Within the last 20 years, total-reflection X-ray fluorescence (TXRF) has been applied to solve a lot of analytical problems. It turned out that TXRF gives an actual approach to nanoanalysis in three different fields: (i) for tiny samples with only nanogram sample amounts; (ii) for low traces with concentrations down to ng/l; (iii) for surfaces and shallow layers with some nanometer thickness. After a short tutorial on total-reflection of X-rays and the formation of standing waves, several selected examples are given for each of the three fields of nanoanalysis. Finally, a critical evaluation of TXRF and its future prospects are given in this survey article.