Analytical strategies for quantifying methylated selenium species in staple crops: Methods, and emerging techniques

• Reviewed analytical methods for detecting selenium methylation in rice and corn. • Explored chromatographic, spectroscopic, and mass spectrometric techniques in detail. • Method sensitivity, selectivity, and limitations are critically evaluated of in complex food matrices. • Examined emerging technologies such as CE-ICP-MS in selenium speciation analysis. • Standardization and quality assurance are important in selenium methylation measurements. Selenium is an essential trace element that exists in various forms, including methylated species, each with distinct biological activities and toxicity profiles. Understanding these transformations is critical for evaluating selenium's role in health and the environment. This review was conducted through a targeted search of multiple databases, including PubMed, Scopus, Web of Science, and Google Scholar. Keywords such as "selenium methylation detection" and "analytical methods for selenium" were used to gather a broad and relevant selection of articles. Studies were included based on their relevance, methodological quality, and contributions to the field. The review provides a detailed analysis of both established and emerging analytical techniques for selenium detection. This includes gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), high-performance liquid chromatography (HPLC), X-ray absorption spectroscopy (XAS), and nuclear magnetic resonance (NMR). It evaluates the effectiveness of these methods in separating, identifying, and quantifying selenium species, with a particular focus on sensitivity, selectivity, and throughput. Additionally, new technologies such as capillary electrophoresis coupled with inductively coupled plasma-mass spectrometry (CE-ICP-MS) and laser-induced breakdown spectroscopy (LIBS) are discussed for their potential to enhance precision and efficiency. This review highlights the critical role of advanced analytical methods in understanding selenium transformations and improving measurement accuracy. By addressing challenges such as matrix effects, overlapping retention times, and spectral interferences, the review underscores the importance of reliable selenium analysis for health and environmental assessments, and provides insights into the ongoing advancements in analytical technology.