A Review of Advances in Analytical Technologies for Phosphorus in Geological Samples

Accurate determination of phosphorus (P) content in geological samples is a crucial prerequisite for in-depth investigations into geochemical behavior, biological effects, and ore-forming mechanisms. Phosphorus content in geological samples varies widely; except for phosphorus-enriched samples such as phosphate ores, most geological samples exhibit low to medium P concentrations (1–1000 g/g), and their complex matrix compositions pose significant challenges to precise quantification of P. This review provides a overview of the analytical techniques for P in geological samples, covering major sample preparation methods and instrumental analyses, and evaluates the characteristics and applicability of these techniques. Sample preparation methods include acid digestion, alkaline fusion, and fused pelletization. Measurement techniques encompass chemical analysis (gravimetry, volumetry) and instrumental analysis, including spectrophotometry, inductively coupled plasma-optical emission spectrometry (ICP-OES), X-ray fluorescence spectrometry (XRF), and inductively coupled plasma-mass spectrometry (ICP-MS). Sample preparation must be compatible with the properties of sample matrices and subsequent analytical techniques, and the selection of these preparation procedures directly affects the precision and accuracy of the results. The instrumental analyses generally provide significant advantages such as low P detection limits (typically at the g/g level), rapid analysis throughput, and simultaneous multi-element determination. However, these techniques are also susceptible to various spectral interferences (e.g., matrix effects and instrument fluctuations). These obstacles can be overcome by optimizing approaches such as matrix-matched standards and internal standard calibration. Existing national and industrial standards for P analysis in geological samples have several limitations, including relatively high limits of detection (typically at the 0.01% level), cumbersome analytical workflows, outdated technical approaches, and insufficient coverage of sample types. Based on an analysis of the characteristics of different sample preparation and analytical methods in relation to sample properties and analytical objectives, this review proposes optimized analytical protocols to provide a scientific basis and practical guidance for the efficient and accurate determination of P in geological samples. The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202412260278.