Determination of bromine, iodine, and other components in northern Hainan island soil

Abstract

The emergence of the integrated wavelength-dispersive and energy-dispersive Zetium X-ray fluorescence spectrometer technique offered new chances to analyze elemental distribution with minimal sample preparation in complex matrix geological samples-northern Hainan island soils. Wavelength-dispersive X-ray fluorescence was applied for the measurement of bromine in the northern Hainan island soil. To reduce the fluctuations of the low-bromine-content measurement results, a two-channel measurement of bromine was designed, and the average value of the two-channel measurements was used as the final result. The soil samples in northern Hainan Island were rich in iodine, with a content range of a few µg/g to more than 100 µg/g, and these were particularly suitable to be analyzed by energy-dispersive X-ray fluorescence spectrometer. The geological samples in northern Hainan Island were brown, purple, and brown-red soil containing kaolinite, ilmenite, rutile, anatase, and goethite. These soil samples were rich in titanium, aluminum, and iron. The titanium concentration in the northern Hainan Island soil was anomalously high (up to 15.05%), far exceeding the content range of the calibration curve. Owing to the empirical coefficient matrix correction method, unreliable or even unreasonable results were obtained for some elements. By systematically mitigating matrix effects through the development of custom reference materials and building matrix-matched measurement and calibration routines, the quantification of Vanadium, Barium, and major components in northern Hainan Island soil samples was optimized. The efficacy of the X-ray fluorescence spectrometer method was confirmed by comparison with inductively coupled plasma–optical emission spectroscopy analysis. This work demonstrates the capability of the integrated wavelength-dispersive and energy-dispersive Zetium X-ray fluorescence spectrometer technique for reliable quantitative elemental analysis of complex matrix geological samples.