Summary of ISO standard 20289: Total reflection X‐ray fluorescence analysis of water

Abstract

The International Standard Organization (ISO) 20289 provides a method for determining the elemental concentration of impurities dissolved in water samples. It exploits total reflection X-ray fluorescence (TXRF) spectroscopy to measure a dried residue on an X-ray reflector. The scope is to provide a chemical metrology for quantitative analysis to obtain traceable results within a defined degree of accuracy and precision according to good practice and in compliance with ISO 17025. Target users include technicians working in laboratories who perform routine analysis of large numbers of samples. The method is specifically focused on determining elements dissolved in drinking, surface and ground water, but it can be also extended to waste waters and eluates if dilution steps are considered. The standard includes the description of all reagents, standards, and materials, including suitable reference materials, which are needed to prepare the sample and ensure quality assurance and control protocols. In addition, the standard presents a detailed description of sample preparation, contributions factors affecting the uncertainty budget, the general procedure to check instrumental calibration, determining limits of detection and quantification, and methods for spectra fitting.

Atomic spectrometry update – a review of advances in environmental analysis

“…3.4.5 X-ray uorescence spectrometry. The ISO Standard 20 289 for total reection X-ray uorescence analysis of water was based 89 on the analysis of a residue dried on an X-ray reector and was intended for the routine analysis of large numbers of drinking, ground and surface waters samples. The method could also be applied to the analysis of waste waters aer sample dilution.…”

2020 atomic spectrometry update – a review of advances in X-ray fluorescence spectrometry and its special applications

“…Publication of ISO standard 20289 for the TXRF spectrometry analysis of water, in particular drinking and ground waters, represented 41 a major advance in the use of the technique. The paper summarised the standard and proposed that the validity of the TXRF spectrometry measurement be related to the threshold mass of the residue.…”

Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) Method Validation: Determination of Heavy Metals in Dietary Supplements

“…Advantages include the element and its concentration being unaffected by matrix effects, its low sensitivity (ppb), requiring small amounts of sample (μg or μL), the use of small quantities of reagents, and not utilizing argon or nitrogen gases. e low background levels result in improved LODs and even 2 pg may be detected for a variety of elements with a counting time of 1,000 s [23][24][25]. Actually, the development and commercialization of TXRF instrumentation, which offers simple operations with a low-cost compact design, have promoted its application in many different fields [24].…”