Original scientific paper
https://doi.org/10.17794/rgn.2026.5.11
OPTIMIZATION OF EXPOSURE TIME IN PXRF PROTOCOLS FOR HIGH-PRECISION GEOCHEMICAL MAPPING OF HEAVY METALS IN SOILS
Oksana Datsko
; Sumy National Agrarian University, H. Kondratieva str., 160, 40021, Sumy, Ukraine
*
Ihor Kovalenko
; Sumy National Agrarian University, H. Kondratieva str., 160, 40021, Sumy, Ukraine
Yurii Spychak
; Sumy National Agrarian University, H. Kondratieva str., 160, 40021, Sumy, Ukraine
Vitalii Yatsenko
; Sumy National Agrarian University, H. Kondratieva str., 160, 40021, Sumy, Ukraine
Olha Bakumenko
; Sumy National Agrarian University, H. Kondratieva str., 160, 40021, Sumy, Ukraine
Olena Melnyk
; Bern University of Applied Sciences Institute of Agricultural, Forest and Food Sciences, Länggasse 85, 3052 Zollikofen, Switzerland
* Corresponding author.
Abstract
This study provides a scientific substantiation of protocols for the use of portable X-ray fluorescence (pXRF) spectrometry for monitoring agricultural soils degraded by anthropogenic impacts, focusing on optimizing exposure time to enhance the reliability of in-situ heavy metal determination. Experimental work conducted with a Niton XL3t GOLDD analyzer on soil samples, with dwell times ranging from 30 to 300 seconds and the application of analysis of variance (ANOVA), established that for elements with low concentrations (below 50 ppm), such as molybdenum (Mo), uranium (U), arsenic (As), copper (Cu), and scandium (Sc), a measurement duration exceeding 240–300 seconds is critical for signal stabilization above the limit of detection (LOD). Conversely, for elements with concentrations of 50-100 ppm (strontium (Sr), rubidium (Rb), zirconium (Zr), barium (Ba), and vanadium (V)), stability of the mean values is achieved in as early as 60 seconds, although increasing the detection time remains a universal tool for minimizing random variability and narrowing confidence intervals. Based on the results, a differentiated approach to pXRF analysis regulation is scientifically justified: for rapid screening of elements with concentrations above 50 ppm, 60–90 seconds is sufficient, whereas for more precise monitoring of elements below this threshold, an extension of analysis time to 240–300 seconds is necessary to ensure data reliability for subsequent land remediation.
Keywords
anthropogenic degradation; environmental monitoring; exposure time; instrumental error; limit of detection (LOD)
Hrčak ID:
352874
URI
Publication date:
27.10.2026.
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