Toshihisa Horiuchi, the co-author of the first total-reflection X-ray fluorescence (TXRF) paper, has died from colorectal cancer at the age of 66 at a hospital in Fukuoka, Japan, where his son is a doctor. Horiuchi was a student at Kurume National College of Technology. Immediately after finishing school, he started work as a technical staffer at Professor Y. Yoneda's lab, Kyushu University. He became convinced that the use of a new detector would be crucial for opening up new opportunities in X-ray spectroscopy, and he eagerly proposed that his supervisor purchase Si(Li) and Ge detectors, although they were too expensive for the university lab at that time. One of the most important applications for the then new detectors was TXRF. The paper, "Optical Flats for Use in X-Ray Spectrochemical Microanalysis", Rev. Sci. Instrum. 42, 1069 (1971) is a very famous work. This reported the first successful results of TXRF. Horiuchi was aware of the significance of trace analysis of bio-medical specimens such as blood etc, and he wanted to employ TXRF for such applications. After the death of Professor Yoneda, he moved to another lab and worked in the field of organic thin films for electronic devices. He contributed substantially to both research and teaching students. On February 14, 2009 at Osaka City University, Japan, Professor K. Matsushige (Kyoto University), who had supervised Horiuchi for more than 18 years, gave a memorial speech, taking advantage of the opportunity of the international symposium on micro and trace X-ray analysis. The participants offered a silent prayer for Horiuchi.
