Chemistry and Materials Science

Abstract: Calibration transfer for portable reagent-strip spectroscopy is challenged by optical and instrumental variation. SpecCal-Transfer examines physics-guided spectral augmentation using 288 SpectroChip spectra representing 12 reagent-strip response classes, eight nominal control-mixture fractions, and three repeated acquisitions. Simulated gain, baseline drift, wavelength displacement, noise, spectral smoothing, missing-band corruption, and combined changes were used to evaluate source-only regression, shift-aware augmentation, neural correlation alignment (CORAL), maximum mean discrepancy (MMD), conventional standardization, and simulated limited-reference adaptation. In an extremely randomized trees (ExtraTrees) evaluation, physics-guided training reduced moderate wavelength-shift root-mean-square error (RMSE) from 0.1476 to 0.1233 (16.53% mean paired reduction) and combined-shift RMSE from 0.1504 to 0.1232 (18.17%). An independent training-size control yielded 0.1240 with expanded augmentation versus 0.1502 without augmentation under moderate wavelength shifts; size-matched gains were smaller. Under wavelength perturbations at previously withheld interior fractions, physics-guided augmentation achieved RMSE 0.1612 versus 0.1661 for a magnitude-matched generic control. Neural alignment and simulated recalibration had condition-dependent effects. These results establish computational robustness under specified measurement mechanisms, not experimental inter-device transfer or analyte-specific concentration accuracy.

Abstract: Phloroglucinol α-pyrones (PG α-pyr) are acylphloroglucinol–α-pyrone conjugates characteristic of Helichrysum and related genera. Helichrysum arenarium, Helichrysum stoechas and Achyrocline satureioides, three medicinal species not yet examined for the class by high-resolution mass spectrometry, were analysed by UHPLC–Orbitrap–MS. The spectra were annotated by an automated R workflow that applies the fragmentation rules established for H. italicum to every MS2 spectrum and matches it against a dictionary of 463 expected compounds. The workflow annotated 201 PG α-pyr (178 in H. arenarium, 55 in H. stoechas, 32 in A. satureioides); with the 58 compounds published for H. italicum, the four species hold 215 PG α-pyr, five of which, arzanol among them, occur in all four. For the 44 compounds shared with H. italicum the automated annotation reproduced the manual one. H. arenarium is the richest species, with 98 compounds detected only there. H. italicum and H. arenarium contain 153 and 78 µg/g PG α-pyr, dominated by arzanol; H. stoechas (8.4 µg/g) and A. satureioides (3.2 µg/g) are each dominated by one compound, a dehydro-geranyl benzopyran and helipyrone A. Unsupervised clustering of the MS/MS spectra recovered the scaffold and the α-pyrone substituent. The class is common to the four species; the dominant subclass and the preferred substituents distinguish them.

Abstract: Trimethylamine (TMA) is a characteristic spoilage marker generated during the late stage of microbial metabolism in crayfish, and its rapid detection is of great significance for ensuring the safety of aquatic products. In this study, a zeolitic imidazolate framework-8 (ZIF-8) and graphene oxide (GO) nanocomposite (ZIF-8@GO) was synthesized via a room-temperature stirring method and subsequently modified onto a glassy carbon electrode (GCE) surface to construct an electrochemical sensor for TMA detection. The composite material and the modified electrode were systematically characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Under optimized conditions, differential pulse voltammetry (DPV) was employed to evaluate the sensor response toward TMA. The oxidation peak current exhibited a good linear relationship with TMA concentration in the range of 5–105 μM, with a limit of detection (LOD) of 1.79 μM (S/N = 3) and a limit of quantification (LOQ) of 5.97 μM (S/N = 10). The sensor displayed excellent reproducibility with a relative standard deviation (RSD) of 0.89% (n = 5), and outstanding long-term stability with an RSD of 1.03% after 10 days of storage. Furthermore, the sensor exhibited superior anti-interference capability against common coexisting ions and organic substances. When applied to the detection of TMA in real crayfish samples, the recoveries ranged from 96.56% to 101.32% with RSDs below 3%, and the results were in good agreement with those obtained by high-performance liquid chromatography (HPLC). The proposed sensor is facile to prepare, rapid in response, and cost-effective, offering a new technical approach for the on-site rapid screening of crayfish freshness.

Abstract: A long-term stability study of a manufactured substance, material, or object (a product) is a known task in analytical chemistry (testing) laboratories serving applied science, industry and trade. It is also an important part of development of reference materials as measurement standards. The main outcome of a long-term stability study is a conformity decision at the point on the time scale when the product property value is expected to violate its tolerance/specification limit. The period of time (the interval on the time scale) from the product fabrication up to this ‘tipping point’, determined with the specified confidence probability, is recognized as the product shelf life or lifetime. After the tipping point, the product is deemed unfit for its intended use. Using a Bayesian approach, the present position paper (a perspective) considers tipping point analysis as a statistical tool to estimate the shelf life of a substance, material, or object, taking into account risks of false decisions in its conformity assessment.

Abstract: Archaeochemical investigations of organic residues have significantly advanced the reconstruction of ancient lifeways by providing molecular evidence of subsistence strategies, ritual behavior, technological practices, and socio-symbolic systems. This study presents a systematic review of archaeochemical scholarship published between 2010 and 2024, synthesizing empirical findings from forty-five peer-reviewed studies retrieved from Scopus, Web of Science, and Google Scholar. Guided by PRISMA 2020 protocols, the review evaluates archaeological materials analyzed, analytical techniques employed, residue categories identified, and interpretive frameworks linking biomolecular signatures to cultural memory and religious practice. The findings demonstrate the methodological dominance of chromatographic and spectrometric approaches, particularly gas chromatography–mass spectrometry, liquid chromatography–mass spectrometry, isotope ratio mass spectrometry, and spectroscopic screening techniques. Lipid biomarkers remain foundational for reconstructing subsistence systems and dietary transitions, while increasing use of proteomic and isotopic analyses has expanded interpretive capacity toward ritual consumption practices, technological knowledge transmission, and spatial organization of domestic activities. Organic compounds such as fatty acids, fermentation markers, terpenoids, nicotine alkaloids, and resinous substances emerge as key proxies for interpreting culinary traditions, ceremonial behavior, and symbolic technological practices. The review highlights a disciplinary shift toward multi-proxy analytical integration and micro-contextual approaches that enhance the reliability of cultural reconstruction. The synthesis suggests that organic residues may be interpreted as biochemical indicators of repeated cultural practices preserved within archaeological materials. Future research directions include the development of comparative residue databases, high-resolution analytical techniques, and interdisciplinary collaboration to support more holistic reconstructions of ancient socio-cultural systems.

Abstract: Gold-nanoparticle lateral flow assays (GNP-LFAs) are attractive for point-of-care testing, but their conventional colorimetric readout often limits analytical sensitivity. This structured review asked which signal-amplification strategies produce the greatest improvement in limit of detection (LOD) relative to a conventional GNP-LFA comparator, and by what magnitude. Candidate records were identified through an investigator-directed keyword search and screened at full text by a single reviewer; 29 of 36 assessed records met eligibility, contributing 36 comparator arms across nine mechanism categories. Reported LOD fold-improvements ranged from no measurable gain to 1000x. Enzyme/catalytic (nanozyme) amplification spanned the widest range (4x–1000x across 5 arms), whereas silver/gold enhancement was the most frequently reported category (7 arms, 4 studies), with gains mostly below 40x and one study reporting up to 488x. Two arms showed no meaningful improvement over a conventional or visual-readout comparator. Gains varied substantially within and between categories and were analyte- and format-dependent; same-study and literature-baseline comparators answer different questions and should not be treated interchangeably. The largest gains came from mechanisms acting on detection chemistry rather than flow control or label loading, although most categories rest on few independent studies. Single-reviewer screening and an investigator-directed search are limitations.

Abstract: Microplastics are increasingly recognized as contaminants of emerging concern in drinking water, highlighting the need to assess drinking-water-contact materials as potential sources of particle release. This study investigated microplastic migration from six materials commonly used in drinking water infrastructure under chlorinated and non-chlorinated conditions using three consecutive migration cycles. Particle abundance, polymer composition, and size distribution were determined by micro-Fourier transform infrared spectroscopy (μ-FTIR). Microplastic release was strongly dependent on material composition. Polyester-derived particles predominated in M1 and M2, polyethylene particles in M3 and M4, and PVC particles in M5, whereas the cementitious lining material (M6) exhibited the lowest release potential. Chlorination influenced particle release in a material-dependent manner, with M2 showing the highest concentrations under chlorinated conditions. Across all materials, most particles belonged to the 20-50 μm and 50-100 μm size classes. Consumer exposure was assessed using a Relative Microplastic Release Index (RMRI), identifying M2 and M5 as the major contributors to potential exposure and M4 and M6 as the most stable materials. Overall, the results demonstrate that material composition governs microplastic release and should be considered when evaluating drinking-water-contact materials and consumer exposure.

Abstract: Accurate potency testing is essential for quality control, regulatory compliance, and consumer safety in commercial cannabis products, particularly as edible and oil formulations increasingly contain complex mixtures of major and minor cannabinoids. In this study, a selective ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the simultaneous quantification of 24 cannabinoids in cannabis-derived oils and gummy products. The method included cannabinoids commonly targeted in AOAC-relevant potency testing, together with additional minor, acidic, varin-type, and degradation-related cannabinoids to support full-spectrum product assessment. Chromatographic separation was optimized to resolve structurally related isomers with identical or highly similar MRM transitions, including Δ9/Δ8 cannabinoid pairs and their acidic and varin analogues. The method demonstrated good linearity across analyte-specific calibration ranges, with LOQs of 0.05-0.1 ng/mL and LODs of 0.005-0.05 ng/mL. Bias values for quality control samples at 4, 400, and 800 ng/mL ranged from -19.3% to 10.1%, meeting the predefined acceptance criterion of +/-20%. Recovery in gummy matrices fortified at 0.04, 0.4, and 4 μ/g was generally within 80-110%, confirming acceptable extraction performance. Application to 14 hemp oil and 18 hemp- or cannabis-infused gummy products revealed wide variations in cannabinoid profiles, with concentrations spanning ng/mL to mg/mL in oils and ng/g to mg/g in gummies. Label comparison further demonstrated substantial deviations for CBD, Δ9-THC, and several minor cannabinoids. This validated method provides a practical tool for comprehensive potency testing, quality assessment, and label-accuracy evaluation of commercial cannabis-derived oils and edible products.

Abstract: Transferring a classical high-performance liquid chromatography (HPLC) ultravio-let/visible (UV/Vis) method into a greener and more sustainable one should consider the safety and toxicology of the solvent used in the method. The organic solvent used in the mobile phase may be replaced by a green solvent that is ideally bio-based and biode-gradable to increase its greenness. However, the implementation of a new solvent for HPLC-UV/Vis requires consideration of its environmental and health impact, cost-effectiveness, user-friendliness, and impact on the chromatographic method perfor-mance and its suitability. Existing greenness, blueness, and redness metrics expressing whiteness for evaluating the comprehensive sustainability of methods after solvent re-placement do not adequately consider the chromatographic suitability of the solvent; this may lead to suboptimal solvent replacement. In this work, the authors present a Universal Suitability and Sustainability Index (USSI), a sixteen-parameter scoring system that quan-tifies four main factors for complete evaluation of a new solvent for implementation in HPLC. The four main factors are chromatographic suitability, greenness, blueness, and redness. The new index has been used to evaluate traditional liquid chromatographic as well as green solvent-based methods to give a universal overview that aids users to drive a rapid impression on the weakness and strength aspects and makes it easier to judge the selection of the solvent and the evaluation of the overall method sustainability.

Abstract: The safe use of insect frass as a fertilizer component requires reliable methods to eval-uate hygienization and storage stability in accordance with European regulation. In this study, 1H NMR profiling of aqueous extracts was applied to Tenebrio molitor frass processed under three thermal conditions: no heat treatment, 70 °C for 1 h, and 70 °C for 18 h. Spectra were acquired at 0, 7, and 14 days to monitor compositional changes during storage. Untreated frass showed a progressive decrease in resonances assigned to α- and β-glucose, together with the emergence of signals in the glycerol region con-sistent with fermentation-derived metabolites, including 3-hydroxypropionate and 1,3-propanediol. These spectral changes indicate ongoing microbial metabolism and limited storage stability. Samples treated at 70 °C for 1 h retained carbohydrate reso-nances for longer but still exhibited measurable spectral evolution over time, suggest-ing partial hygienization rather than complete stabilization. By contrast, the 70 °C for 18 h treatment produced the most stable spectral profiles, with minimal changes throughout storage. Overall, these results demonstrate that ¹H NMR profiling can serve as a rapid analytical approach to assess thermal hygienization and detect stor-age-related metabolic drift in frass. The method offers a practical way to compare steri-lization strategies and to support the evaluation of microbiological stabilization in frass-based fertilizers under regulatory frameworks.

Abstract: Decaffeinated coffee is widely perceived as being virtually caffeine-free; however, complete caffeine removal is not achieved by commercial decaffeination processes, and residual caffeine in retail products may vary considerably. This study aimed to develop and vali-date a high-performance liquid chromatography method with ultraviolet detection HPLC–UV for the determination of residual caffeine in commercial decaffeinated coffee products. Sixteen products representing instant, ground, whole-bean, and capsule formats were analyzed. Chromatographic separation was achieved using a C18 reversed-phase column with a water–methanol gradient and UV detection at 272 nm. Method validation was performed according to the ICH Q2(R2) guideline, including system suitability, line-arity, precision, accuracy, recovery, and limits of detection and quantification. The method demonstrated excellent linearity over 0.05–5.0 ppm (R² = 1), with recoveries of 98.2–102.7% and repeatability and intermediate-precision RSDs below 2%. The LOD and LOQ were 0.0081 and 0.0245 ppm, respectively. Residual caffeine concentrations ranged from 0.051% to 0.175% (w/w). Ten products (62.5%) were at or below the 0.1% reference thresh-old, whereas six (37.5%) exceeded it. Although product category significantly affected re-sidual caffeine levels, substantial within-category variability was observed. The validated HPLC–UV method provides a rapid and reliable approach for routine quality control and post-market surveillance of residual caffeine in commercial decaffeinated coffee products.

Abstract: Transmission Fourier transform infrared spectroscopy (FTIR) is a very useful analytical technique for determining the types of functional groups present in a sample for various applications. However, the method remains qualitative, and lacks the ability to determine the relative abundance of different functional groups, or to quantify a specific compound in a sample. In this work, an attempt was made to develop quantitative FTIR as an analytical technique able to determine the relative amounts of an analyte in a sample, in this case, sodium acetate via the conventional KBr window transmission mode FTIR method. Results revealed that there was an infrared spectrum region (1700 to 2800 wavenumber) where there is response of percentage transmission with amount of sodium acetate added. Further analysis of this spectrum region revealed two distinct calibration windows of 1800 to 2000 wavenumber, and 2560 to 2680 wavenumber. Both calibration windows yielded good, linear calibration curves of good correlation coefficients of between 0.97 to 0.99. Hence, data in this work suggests that it may be possible to further develop a quantitative FTIR method to quantify the amount of sodium acetate in samples.

Abstract: Accurate quantification of nitrate (NO_3-) in tropical drinking water sources is routinely compromised by significant interference from natural organic matter. This study evaluated three regulatory standard methods (APHA 4500-NO_3- B, E, and J) against an optimised homogeneous vanadium (III) chloride (VCl₃) reduction assay. Optimal VCl3 operational parameters were established at 1.0 M HCl, 60°C incubation, and a 45 min reaction time. Results revealed major disparities in matrix tolerance across evaluated pathways. Direct UV Spectrophotometry (Method B) failed in samples with dissolved organic carbon levels exceeding 3.0 mg C/L due to non-linear spectral overlap. Enzymatic reduction (Method J) suffered severe humic acid inhibition, dropping recoveries to 54.1±4.2 % at 20.0 mg C/L DOC. Conversely, chemical reduction pathways (Cd and VCl3) maintained high selectivity and matrix tolerance (98.5%-101.2% recovery) by shifting spectral detection to = 540 nm. The optimised VCl3 method achieved a limit of quantification (LOQ of 0.010 mg N-NO3-/L, intra-day repeatability of 1.0%-2.2% RSD, and superior multi-analyst reproducibility (2.2%-3.8% RSD) compared to cadmium column reduction (4.5-6.2% RSD). Operating as a single-phase liquid system, the VCl₃ protocol eliminates packed-bed column maintenance, flow-rate dependence, and toxic cadmium waste generation, providing a robust, cost-effective, high-throughput solution for tropical water testing laboratories.

Abstract: This study describes the synthesis, characterization, and evaluation of enantiomeric recognition properties of two fluorescent chiral ionic liquids (FCILs), L-aspartyl-L-phenylalanine methyl ester bis-(trifluoromethanesulfonyl) amide [ASP] [NTf₂] and L-aspartyl-L-phenylalanine methyl ester bis-(perfluoroethylsulfonyl) imide [ASP] [BETI]. The two FCILs were synthesized by means of ion-exchange between L-aspartyl-L-phenylalanine methyl ester hydrochloride [ASP] [HCl] and the lithium salts of bis-(trifluoromethanesulfonyl) amide (LiNTf₂) and bis-(perfluoroethylsulfonyl) imide (LiBETI). The products FCILs, [ASP] [NTf₂] and [ASP] [BETI], were viscous liquids at room temperature and were stable up to 366 oC. UV and fluorescence studies indicated the FCILs were highly UV absorptive and had strong fluorescence backgrounds. Fluorescence studies demonstrated the FCILs ability to discriminate between the enantiomers of naproxen and propranolol indicating ability serving as effective fluorescent recognition agents for chiral pharmaceutical analytes.

Abstract: This quantification methodology eliminates the need for complex and time-consuming pretreatments, like digestion or extraction, by leveraging digital-image colorimetry. It relies on a chromogenic complexation reaction within the emulsion, between the target metal and a suitable reagent: quercetin for aluminum and ferrozine for iron. For aluminum, the method demonstrated linearity with R² ≥ 0.971, acceptable accuracy (relative bias ≤ ±8.5 %) and intermediate precision (CV ≤ 9.4 %) upon Quality Controls (above the LLOQ) analysis and was successfully applied to commercial antiperspirants with satisfactory accuracy (relative bias ≤ ± 15.2 %). The assay was also adapted to a paper-based format. For iron, the method showed a linear correlation (R² ≥ 0.981) acceptable accuracy (relative bias ≤ ± 13.7 %) and intermediate precision (CV ≤ 12.6 %) upon Quality Controls analysis; it was further validated against X-ray fluorescence, revealing a consistent small positive bias of 14%. Investigations showed that both assays are susceptible to interference from common chelators and certain metals. We have demonstrated that the effect of such common interferences in commercially relevant concentration was, however, minimal (relative bias of ≤ ± 15.2  for Al and ≤ ± 4.5  for Fe), when the matrix of samples and standards was matched (e.g. upon sample dilution). For routine industrial quality control of emulsions, the proposed method is a cost-effective and greener alternative that, although mostly inferior in terms of technical characteristics when compared to instrumental analysis methods, is sufficiently accurate, precise and selective under the defined conditions.

Abstract: Breast-cancer management depends on reproducible molecular classification, yet tissue-based assays provide only spatially and temporally restricted views of a heterogeneous disease. Aptamers are programmable single-stranded DNA or RNA ligands that can integrate molecular recognition with biosensing, liquid-biopsy capture and targeted delivery. This Review follows the translational chain from aptamer selection and molecular recognition to subtype resolution, signal or cargo conversion, biological validation and clinical translation. We compare HER2-directed aptamers, ERα- and PHB2-associated tools for hormone-receptor-positive disease, and phenotype-oriented ligands for triple-negative breast cancer. We further organize aptasensors by signal-conversion mechanism, distinguish analytical performance in buffer from that in clinical matrices, and clarify the complementary role of aptamers in liquid-biopsy workflows, including enrichment rather than direct sequence-variant detection of circulating tumour DNA. For theranostic systems, affinity alone is insufficient; pharmacokinetics, receptor trafficking, endosomal escape and comparator-controlled efficacy ultimately determine functional benefit. Aptamers are therefore most compelling as modular recognition elements for multiplexing, reversible engineering and targeted delivery. Progress will depend on transparent selection reporting, orthogonal target validation and prospective multicenter studies.

Abstract:

The ongoing climate crisis, caused by the annual release of 37 billion metric tons of CO₂ emissions, is putting pressure on the advancement of Carbon Capture and Storage (CCS) and Direct Air Capture (DAC) technologies. Metal–Organic Frameworks (MOFs), with their high surface areas and modular pore topologies, present a very attractive class of sorbents for CO₂ capture; however, it currently remains computationally prohibitive to explore their extensive chemical design space. Herein, we provide a thorough evaluation of how machine learning (ML) (as an emerging technology) has played an increasing role in furthering our understanding of CO₂ capture from MOFs. Through an organized investigation, we provide evaluations of the latest generation of models across four key areas: application at a process level, mechanistic interpretable modelling; physically relevant descriptors, and predictive performance metrics. Recent work with Machine Learning Interatomic Potentials (MLPs) shows that traditional assumptions about rigid frameworks are being challenged by the fact that diffusion properties and adsorption thermodynamics are heavily influenced by the flexibility of the framework. The use of physics-informed descriptor engineering yields R² values of 0.81-0.97 across gas species and pressure regimes, while the generative nature of Deep Reinforcement Learning and transformer-based architectures has been shown to allow for the inverse design of frameworks with high affinities for gas species. The trend in this sector is moving towards optimization of multiple scales simultaneously and integrating processes to achieve an optimized property prediction. Current work with machine learning is focusing on using a combination of material properties and operational indicators (such as how much gas is recovered through pressure swing adsorption) to make predictions. As these techniques improve, there will be a similar need for a design that is both physically informed and understandable, thus allowing for a link between molecular discoveries and water-stable materials that have been experimentally verified and are suitable for use in commercial applications.

Abstract: Paralytic shellfish toxins (PSTs), potent neurotoxic alkaloids produced by marine dinoflagellates and cyanobacteria, pose severe risks to human health via contaminated seafoods and waters. Current detection methods suffer from low specificity, matrix interference, or ethical concerns. Here we report a novel screening approach using vanadium pentoxide as an oxidant to convert PSTs into characteristic oxidation products, followed by high-performance liquid chromatography-tandem mass spectrometry (HPLC‒MS/MS) analysis. Under optimized conditions, vanadium pentoxide oxidizes both hydroxylated and non-hydroxylated toxins into distinct major products (P1‒P7), identified by high-performance liquid chromatography‒tandem high-resolution mass spectrometry (HPLC‒MS/HRMS). Vanadium pentoxide oxidation affords excellent product selectivity and, for most PSTs, superior signal intensities, enabling unambiguous differentiation of toxin subgroups. HPLC‒MS/MS on MRM mode was developed and yielded detection limits of 0.3‒1.5 ng/mL for a broad-spectrum of 14 PSTs in spiked plasma, recovery percentages of 81.8‒102.2%, and excellent repeatability with intra- and inter-day relative standard deviation (RSDs) ranged from 0.3% to 10.4%. Application to the First Trial OPCW (the Organisation for the Prohibition of Chemical Weapons) Biotoxin Proficiency Test samples successfully identified STX/neoSTX, confirming its practical utility for trace PSTs detection in complex biological matrices.

Abstract: Continuous, real-time monitoring of volatile organic compounds (VOCs) in surface water is critical for environmental protection, yet conventional laboratory Gas Chro-matography-Mass Spectrometry (GC-MS) suffers from analyte loss during sample transport. This study field-validates a portable Membrane Inlet Mass Spectrometry (MIMS) system for direct, on-site monitoring of seven target VOCs (benzene, toluene, xylenes, chlorobenzene, 1,2-dichloroethane, trichloroethylene, and tetrachloroeth-ylene). Laboratory validation established limits of detection between 4 and 8 µg/L, strong linearity (R2 > 0.98), and acceptable precision and accuracy per AOAC guide-lines, benchmarked against headspace GC-MS. In-field testing at 36 locations across the Danube-Tisa-Danube (DTD) irrigation canal demonstrated system robustness. Baseline canal samples remained below detection limits, but real-time MIMS success-fully identified localized benzene and toluene contamination near a gasoline station. On-site MIMS detected significantly higher volatile concentrations than delayed la-boratory GC-MS, demonstrating its key advantage in preventing sampling volatiliza-tion losses. Portable MIMS proves to be a powerful, rapid screening tool for continuous aquatic environmental monitoring.

Abstract:

Organochlorine pesticides (OCPs) residues act as critical drivers of environmental impacts and pose significant risks to human and animal health. This scenario is further exacerbated by their high environmental persistence, marked bioaccumulative potential, and chronic toxicity. The International Agency for Research on Cancer (IARC) classifies dieldrin as well as aldrin, when metabolized into this substance, as probably carcinogenic to humans (Group 2A). OCPs can accumulate in the fatty tissue of fish. Therefore, when consumed, fish can become a route of human exposure to OCPs, such as dieldrin. A novel method for determining dieldrin in Fillets of Nile tilapia (Oreochromis niloticus) using GC/MS and the original QuEChERS was developed and validated. The optimization of chromatographic parameters resulted in an appropriate retention time (R_t) for dieldrin. Matrix-matched calibration was established to correct the matrix effect (ME) in the quantitative analysis of the pesticide. Dieldrin showed matrix-induced signal suppression of -21.17%. The pesticide studied showed good linearity with a coefficient of determination (R²) of 0.9918. According to the analytical validation standards established by ANVISA, concentrations above the LOQ (50 μg L^-1) can be used as a linear working range with high reliability.