The Ruland streak method is widely used in small-angle x-ray scattering (SAXS) to quantify the length and orientation of scatterers, but lacks systematic error quantification under varying microstructural conditions, limiting its quantitative reliability. In this work, we present a benchmarking and computational verification framework for the Ruland streak method, utilizing simulated SAXS patterns of dilute cylindrical scatterers parameterized by distribution full width at half maximum (FWHM), aspect ratio, and size distribution. This framework is applied to assess the accuracy, limitations, and scope of applicability of the Ruland streak method in microstructural characterization. Furthermore, contour maps of relative errors are presented to quantitatively evaluate the fitting errors of the results, allowing the extracted parameters to more closely approximate the true physical values. In addition, preliminary validation is carried out using oriented gold nanorod samples. Although the Ruland streak method demonstrates certain computational deviations, the core principles the Ruland streak method embodies remain fundamentally valid. Additionally, by modifying the scattering intensity function, the proposed framework can be extended and applied to error validation for other SAXS-based methods.
The present study evaluated the applicability of Portable X-ray Fluorescence (pXRF) for rapid determination of seed mineral concentrations in cowpea [Vigna unguiculata (L.) Walp.] by comparing pXRF measurements with those obtained using Atomic Absorption Spectroscopy (AAS). Fifty-seven cowpea genotypes, including two check varieties, were analysed for iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), potassium (K), and calcium (Ca). Simple linear regression was used to assess the relationship between pXRF- and AAS-derived mineral concentrations using training (n = 47) and independent validation (n = 10) datasets. The pXRF measurements showed good agreement with the corresponding AAS values for both macro- and micronutrients, with comparatively stronger relationships observed for Fe, Zn, Mn, and Cu. Residual and normal Q-Q plot analyses supported the suitability of the regression models. The findings demonstrate that pXRF enables rapid, simultaneous multielement analysis with minimal sample preparation and provides an efficient approach for high-throughput mineral phenotyping and biofortification-oriented cowpea breeding programmes.
ABSTRACT X‐ray fluorescence (XRF) spectrometry has been an important tool in agricultural studies recently. This technique allows the multielemental, direct, and in situ analysis. The objective of this review is to evaluate the use of XRF in agriculture focusing on plant and soil samples based on indexed articles in the Scopus database from 2020 to 2024. Particularly, the review evaluated the hardware XRF set‐up (portable XRF, benchtop, and micro‐XRF), the analysis site, and instrumental operational conditions (measurement time (s), filter, atmosphere (air, vacuum, and He)), X‐ray tube voltage (kV) and current (μA), and detector. We highlight the major use of the pXRF for both matrices. The laboratory is the prevailing analysis site, even for the pXRF application. A worrisome finding from this review was the lack of proper description of the instrumental operational conditions, observed in 26% to 78% of the studies verified, considering the above‐mentioned parameters for plant and soil matrices. In short, this review unfolds the increasing use of XRF and features of its set‐up and analysis configuration in agriculture. In addition, it also alerts to the improper description of the operational conditions, as well as discusses opportunities, challenges, and future perspectives for advancing XRF applications in agriculture from the hardware standpoint.
