Reduction of Spectral Interference between X-ray Peaks Originating from an X-ray Tube and X-ray Fluorescence Peaks in Total Reflection X-ray Fluorescence Analysis

Abstract

This paper describes a method for improving the detection limit for zinc by a portable total reflection X-ray fluorescence (TXRF) spectrometer with a tungsten target X-ray tube. Measuring a TXRF spectrum of a small amount of sample in a vacuum remarkably reduced the intensity of the W Lα line (8.40 keV) that originated from the X-ray tube and that partially overlapped with the Zn Kα line (8.63 keV), leading to an improvement in the detection limit for zinc. A detection limit of 0.003 mg/L was achieved when a TXRF spectrum of a 0.05 mg/L zinc standard solution was measured in a vacuum. A TXRF spectrum of a river water sample containing 0.05 mg/L of zinc was also measured, and the Zn Kα line measured in a vacuum was more clearly observed than that measured in air.