Total reflection of X-rays occurs on the surface of a measured object by X-ray irradiation at an extremely low glancing angle (less than 0.1°). X-rays penetrate into a measuring object to a depth of only several (≈10) nm. Therefore, elements on the surface of the sample carrier are excited efficiently and the background intensity occurring from the sample carrier is extremely low. As a result, spectra with high S/N ratio can be obtained. High-sensitivity analysis for trace elements on the surface of the sample carrier can be performed by the total reflection method with a total reflection X-ray fluorescence (TXRF) spectrometer. Concentrations of μg/L (ppb) for inorganic components in a water sample are easily determined by using the internal standard method. Analysis results of beverage samples (drinking water and soft drink), milk, coffee, tea and wine by TXRF are reported. Many more TXRF results of serum samples by acid decomposition are also reported(3). Recently, TXRF spectrometry is widely used for liquid analysis because TXRF spectrometry was made an official liquid analysis method by the International Organization for Standardization (ISO). In this paper, water analysis by TXRF is described and, beverages and serum are introduced as analysis examples.
Atsushi Ohbuchi and Hikari Takahara