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The publication of this editorial collection arrives at a moment when analytical science is being reshaped by forces that extend well beyond the laboratory bench. The COVID-19 pandemic, referenced by the editors as a catalyst for the field’s recent acceleration, exposed how quickly diagnostic and surveillance infrastructures must scale when public health demands it. The rapid deployment of nucleic acid amplification tests, antigen-based lateral flow assays, and mass spectrometry-based workflows during that period demonstrated that analytical methods are not merely academic exercises but critical components of societal resilience. The eleven contributions gathered in this Research Topic reflect that same urgency, addressing problems that range from pharmaceutical quality assurance to environmental remediation, and each illustrates a different facet of how measurement science underpins decision-making across medicine, industry, and environmental stewardship.

One theme that deserves further elaboration is the emphasis on methodological rigor that runs through several of the collected papers. The comparative assessment of hydrochlorothiazide formulations by Wondmkun and colleagues is a case in point. In vitro equivalence testing is a cornerstone of generic drug regulation, and the finding that certain tablet brands passed standard quality control parameters while failing hardness and friability tests highlights a subtle but consequential point: compliance with chemical identity and assay specifications does not guarantee mechanical robustness. Hardness and friability relate directly to how tablets withstand handling, packaging, and transport, and failures in these physical parameters can compromise dose uniformity even when the active ingredient is chemically correct. This underscores why pharmacopeial standards require multiple, orthogonal tests, and why regulators in many jurisdictions continue to refine post-market surveillance protocols that catch such discrepancies before products reach patients.

The work on parallel reaction monitoring by Bezearosti and colleagues similarly speaks to a broader transition in biomarker quantification. Traditional immunoblotting, while historically indispensable, suffers from limitations in dynamic range, antibody specificity, and quantitative reproducibility. Targeted mass spectrometry approaches such as PRM, executed on high-resolution instruments, allow researchers to monitor specific precursor-to-fragment transitions with high selectivity, enabling absolute quantification when calibrated with stable isotope-labeled standards. The shift from antibody-based to mass spectrometry-based detection is particularly significant in clinical proteomics, where inter-laboratory variability has long hindered the translation of candidate biomarkers into validated diagnostic assays. The sensitivity and specificity advantages described in this collection align with a growing consensus that targeted proteomics can achieve the analytical performance characteristics traditionally associated with small-molecule assays.

The separation of phosphorothioate oligonucleotides by capillary electrophoresis using cyclodextrin-based additives, as reported by Ghassemi and co-workers, touches on one of the most technically demanding areas of modern pharmaceutical analysis. Phosphorothioate oligonucleotides, in which a non-bridging oxygen atom is replaced by sulfur, are central to antisense therapeutics and RNA-targeting drugs. Each phosphorothioate linkage introduces a stereocenter, meaning that a 20-mer with full phosphorothioate backbone modification exists as a mixture of over five hundred thousand diastereomers. Resolving these species, or at least characterizing their distribution, is essential for understanding drug identity, stability, and pharmacological behavior. Cyclodextrins, with their chiral hydrophobic cavities, can act as pseudostationary phases or dynamic coatings in capillary electrophoresis, providing chemo- and stereoselective interactions that conventional separations cannot achieve. This work exemplifies how supramolecular chemistry continues to find practical application in the quality control of increasingly complex biopharmaceuticals.

Multi-energy calibration in plasma-based optical emission spectrometry, introduced by Jofre and colleagues for mineral analysis of animal feeds, addresses a persistent challenge in inductively coupled plasma spectroscopy: matrix effects. When complex samples such as feeds are introduced into a plasma, coexisting matrix components can alter nebulization efficiency, plasma temperature, and ionization equilibrium, leading to signal suppression or enhancement that compromises accuracy. Multi-energy calibration strategies use multiple emission lines for each analyte, exploiting the fact that matrix effects may influence different transitions to different degrees. By fitting across these energies, the approach can compensate for non-spectral interferences and yield more accurate concentrations. In the context of livestock nutrition, where precise mineral content affects animal health, growth rates, and ultimately food safety, improved analytical accuracy translates directly into better feed formulation and reduced waste of supplemented minerals.

The phytochemical characterization of Zishen Yuzhen Pill by Cheng and colleagues illustrates the analytical complexity inherent to traditional medicine research. Herbal formulations contain hundreds of constituents whose identities, abundances, and metabolites must be mapped to understand mechanism of action. Ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry provides the mass accuracy and resolution needed to tentatively assign molecular formulas and fragment ions, and the identification of 152 compounds, 99 metabolites, and 70 prototype components in rat tissues represents a substantial chemometric undertaking. Such work is essential for bridging traditional empirical knowledge with modern pharmacology, allowing researchers to trace which constituents are absorbed, distributed, and potentially responsible for the observed promotion of osteogenic differentiation. It also highlights the growing role of metabolite profiling in preclinical evaluation of complex natural product mixtures.

The perspective on protein carbamylation by You and colleagues raises an issue that many practitioners of bottom-up proteomics will recognize. Urea is a near-universal denaturant in sample preparation, yet it slowly decomposes to cyanate, which reacts with protein N-termini and lysine side chains to form carbamylated products. Because carbamylation mimics acetylation in terms of mass shift, it can confound studies of lysine acetylation, a biologically important post-translational modification. The co-purification of acetylated and carbamylated peptides with anti-acetyl-lysine antibodies, as discussed in this collection, illustrates how an analytical artifact can masquerade as a biological signal. Distinguishing genuine acetylation from urea-induced carbamylation requires careful control of sample preparation conditions, fresh urea stocks, alternative denaturants, and orthogonal confirmation strategies. The broader lesson is that post-translational modification studies demand not only sensitive instrumentation but also meticulous attention to chemical provenance throughout the workflow.

The concept of the sewage exposome, articulated by Picó and colleagues, represents an evolution in how analytical chemists think about environmental monitoring. Wastewater-based epidemiology originally gained prominence through its use in tracking illicit drug consumption and later proved invaluable during the pandemic for monitoring SARS-CoV-2 RNA loads as a population-level infection indicator. Extending the framework to encompass small-molecule drug metabolites, proteins, and other biomarkers moves the field toward a holistic snapshot of community exposure and health status. High-resolution mass spectrometry, with its capacity for non-targeted screening and retrospective data analysis, is the enabling technology for this expansion. The sewage exposome concept acknowledges that what a population is exposed to, metabolizes, and excretes can be read from a composite matrix, offering public health authorities a real-time, anonymized surveillance tool that complements individual clinical testing.

The review by Kundu and colleagues on microalgae for phytoremediation connects analytical science to sustainability in a direct way. Microalgae can assimilate nitrogen and phosphorus from wastewater while simultaneously accumulating heavy metals, pharmaceuticals, and other emerging contaminants. Understanding the uptake mechanisms, whether through surface adsorption, active transport, or intracellular sequestration, requires the same analytical toolkit used elsewhere in this collection: elemental analysis, chromatographic separation, and mass spectrometric identification. The promise of a low-cost, sustainable remediation strategy depends on rigorous quantification of removal efficiencies, biomass productivity, and the fate of captured contaminants, all of which are analytical measurement problems. This illustrates how advances in analytical capability enable progress in seemingly distant fields.

Ratiometric sensing, as examined by Madhu and colleagues, addresses one of the most persistent sources of error in optical and electrochemical measurement: signal drift. In conventional single-channel measurements, fluctuations in light source intensity, detector gain, probe concentration, or electrode surface condition directly translate into apparent changes in analyte signal. Ratiometric approaches circumvent this by measuring the ratio of two signals, one responsive to the analyte and one serving as an internal reference. Because both signals are affected similarly by instrumental and environmental drift, the ratio remains stable even as absolute intensities fluctuate. The extension of this principle across fluorescence, Raman spectroscopy, electrochemistry, and mass spectrometry demonstrates its generality, and its particular value in complex biological or environmental matrices where matrix effects would otherwise be difficult to control.

The discussion of 3D-printed analytical devices by Malinick and colleagues points toward a democratization of instrumentation that could reshape laboratory practice. Additive manufacturing allows researchers to fabricate custom microfluidic channels, optical mounts, and mechanical fixtures in days rather than weeks, at a fraction of the cost of conventional machining. When combined with open-source design files and low-cost electronics, this approach lowers the barrier to entry for laboratories in resource-limited settings and accelerates iteration during method development. The integration of microfluidic, optical, and mechanical components into single printed assemblies foreshadows a future where analytical instruments are not only purchased but also designed, shared, and modified by their users, much as open-source software transformed computing.

Protein-templated metal nanoclusters, the subject of the review by Chu and colleagues, occupy a fascinating niche at the intersection of nanotechnology, biochemistry, and spectroscopy. When metal atoms aggregate into clusters of just a few to a few dozen atoms, quantum confinement effects give rise to discrete electronic transitions and, in many cases, photoluminescence. Protein scaffolds such as serum albumin can direct the nucleation and growth of these clusters, providing both a reducing environment and a protective shell that stabilizes the cluster against aggregation. The resulting luminescent probes offer advantages over conventional organic dyes, including larger Stokes shifts, resistance to photobleaching, and inherent biocompatibility, making them attractive for biosensing and bioimaging applications where long observation times and low background are essential.

Taken together, the contributions in this collection reveal analytical science as a discipline defined by its adaptability. Whether the challenge is resolving stereoisomers of therapeutic oligonucleotides, compensating for matrix effects in elemental analysis, distinguishing artifacts from biology in proteomics, or building instruments from printed parts, the common thread is a commitment to measurement integrity. The editors’ observation that these works emerged from close collaborations and well-honed methodological expertise is worth emphasizing: analytical breakthroughs rarely come from isolated insight but from teams that combine chemical intuition, instrumental skill, and domain knowledge. As the field continues to evolve, driven by advances in automation, machine learning, and miniaturization, the foundational principles of careful validation, orthogonal confirmation, and transparent reporting that animate these papers will remain the standard against which future innovations are judged.

Subject of Research: Analytical science research

Article Title: Editorial: Thought leaders in analytical science research

Article References: Unnikrishnan, B., Huang, C.-C., Chang, H.-T., Psillakis, E., Marini, F., & Grant, J. T. (2025). Editorial: Thought leaders in analytical science research. Frontiers in Analytical Science, 5, Article 1596778. https://doi.org/10.3389/frans.2025.1596778

Image Credits: AI Generated

DOI: 10.3389/frans.2025.1596778

Keywords: Editorial, Thought, leaders, analytical, science, research, scientific research