FUNDAMENTALS OF X-RAY FLUORESCENCE - Total-Reflection X-Ray Fluorescence Analysis and Related Methods - page 11

Figure1.5. Four pioneers of TXRF analysis, from left to right: Peter Wobrauschek, Hannes
Aiginger, Heinrich Schwenke, and Joachim Knoth were awarded the“Bunsen-Kirchhoff Prize”in
1991. Photo by R. Klockenkämper, private property.
(Figure 1.6a) and TXRF (Figure 1.6b) within the last 40 years. The number of
all XRF papers started in 1970 at a level of about 100 papers per year, remained
constant for 20 years, and exponentially increased after 1990 to a rate of 2500
papers per year. Between 1970 and 1985, TXRF papers appeared only
sporadically. But in the years after 1986, their number grew explosively
from some 3 to about 125 papers per year with large fluctuations. The impact
of the special issues after every single TXRF conference can be recognized as
special peaks, repeating every 2 years after 1989. Altogether, 1250 articles have
been published in the field of TXRF. It is interesting to mention that only eight
authors are connected with 30% of all published papers in this field.
The method of TXRF has been developed significantly and has become a
high-performance variant of classical X-ray fluorescence. For a lot of elements,
the detection limits are on the pg-level and even below. In general, all elements
except for the light elements can be detected. TXRF analysis can be compared
with ET-AAS, which is the high-power specialty of FAAS, and with ICP-MS,
which even tops ICP-OES. TXRF ranks high among these competitive meth-
ods of element spectral analysis.
In the last 15 years after the first edition of this monograph, different
review articles on TXRF have been published summarizing new develop-
ments and results [32-34]. Book contributions furthermore describe the
subject with different aspects, for example, wafer analysis [35-37]. Specific
articles deal with further developments, such as excitation with synchrotron
radiation [38,39], with standing waves by grazing incidence [40,41], with
biological applications [42], with sample preparation [43], and with portable
instruments [44]. Today, TXRF is successfully applied all over the world