Melamine

J Appl Toxicol. 2025 Oct 11. doi: 10.1002/jat.4953. Online ahead of print.

ABSTRACT

Graphene oxide (GO) and carbon nanotube (CNT)-based nanomaterials have attracted significant interest in various industrial and biomedical applications due to their unique physicochemical properties; however, concerns about their potential toxicity, especially when modified with additives like melamine (M), remain largely unresolved. This study investigates the toxicological effects and underlying mechanisms of graphene oxide-melamine (GO-M) and carbon nanotube-melamine (CNT-M) nanoparticles in zebrafish (Danio rerio) embryos and larvae. To this end, developmental toxicity, phenotypic and behavioral changes, as well as histopathological and immunofluorescence alterations, were evaluated following acute exposure to GO-M and CNT-M nanoparticles at concentrations of 5, 10, and 20 mg/L. Results showed that both nanoparticles delayed larval hatching, particularly at higher concentrations (10 and 20 mg/L). Malformations were observed at 20 mg/L in the GO-M group and at 10 and 20 mg/L in the CNT-M group. Additionally, significant changes in larval length and eye area were observed at all concentrations for both nanoparticles. Behavioral assessments revealed that CNT-M exposure at 10 and 20 mg/L significantly impaired head sensorimotor reflexes, while all concentrations affected tail reflexes. In contrast, GO-M exposure did not significantly alter sensorimotor responses. These findings suggest differential toxic mechanisms and neurobehavioral effects of GO-M and CNT-M nanoparticles during early zebrafish development.

PMID:41074713 | DOI:10.1002/jat.4953

Food Chem Toxicol. 2025 Sep 30:115773. doi: 10.1016/j.fct.2025.115773. Online ahead of print.

ABSTRACT

Exclusive Enteral Nutrition (EEN) can induce remission in Crohn's disease (CD). We completed a pilot study using novel reverse-engineered EEN (RE-EEN), a whole food smoothie in place of commercial liquid formula (EEN) which contains food additives to improve shelf stability and palatability. In a four week trial with RE-EEN, we reported 80% of patients went into clinical remission after four weeks. We hypothesized RE-EEN would decrease environmental toxin exposure through reduction of processing food intake. Biosamples were collected at baseline and at weeks two, four, and eight during the RE-EEN study. Urinary heavy metals were analyzed by inductively coupled plasma mass spectrometry, and urinary phthalate metabolites and melamine by liquid chromatography with tandem mass spectrometry. For our primary analysis, change in baseline was calculated using a paired t-test for week four. Analysis was also completed for all weeks on RE-EEN using a generalized least squares model. Results were expressed as fold change ± standard error mean. Paired t-testing demonstrated a statistically significant (p<0.05) effect on molybdenum (Mo) with a fold change of 0.17 ± 0.15, an 83% reduction following RE-EEN treatment. Our results suggested an effect of arsenic (As) with fold change of 0.23 ± 0.26 (p=0.12), a 77% reduction following RE-EEN treatment. Our results also suggested an effect of cobalt (Co) with a fold change of 3.12 ± 3.12 fold, a 212% increase following RE-EEN therapy (p=0.16). With inclusion of all weeks on RE-EEN, Mo and As were statistically significant (p<0.05). Overall, we observed favorable shifts in urinary heavy metals by week four, and no effects were suggested in phthalate and melamine analysis. We saw increased precision in a sensitivity analysis when including all weeks for treatment. This is the first study to examine environmental toxicants in relation to whole foods smoothie diet in pediatric CD. RE-EEN dietary intervention shows promise in reducing chemical exposures and may contribute to CD remission. Notable limitations to this research include small sample size and absence of a control group. Further studies are necessary to assess the impact of RE-EEN diet on environmental toxicant exposure.

PMID:41038373 | DOI:10.1016/j.fct.2025.115773

J Hazard Mater. 2025 Sep 16;498:139914. doi: 10.1016/j.jhazmat.2025.139914. Online ahead of print.

ABSTRACT

Landfill leachate (LFL) typically contains a wide range of potential pollutants, making it difficult to treat and inefficient in resource utilization. This work developed a new multifunctional evaporator that integrated photothermal evaporation with photocatalytic degradation to enable in situ purification and water recovery. The device was fabricated by immobilizing a hydrothermally synthesized Nickel Oxide- Titanium Dioxide- Carbon Nanotube (NiO-TiO₂-CNT) composite on a melamine sponge via sodium alginate crosslinking, forming a synergistic evaporation-degradation interface. Under 1 kW·m⁻² solar irradiation, the system achieved an evaporation rate of 2.25 kg·m⁻²·h⁻¹ , where the addition of 1 mmol·L⁻¹ PMS boosted phenol removal efficiency to 90 %. When applied to real LFL, COD was reduced from 4266 to 53 mg·L⁻¹ , and phosphate was completely removed to below detection limits (<0.01 mg·L⁻¹). Although ammoniacal nitrogen levels remained relatively high at 354 mg·L⁻¹ , post treatment phytotoxicity tests involving irrigation of wheat with leachate resulted in a 90 % germination rate, which increased to 100 % after dilution. This indicated the treated leachate was safe and could potentially be used as a nitrogen-rich liquid fertilizer. A techno-economic analysis showed that the system could be operated at a cost of only 10.33 USD per metric ton, significantly lower than conventional treatments. This work thus provides a cost-effective sustainable strategy for simultaneous pollutant control, water reuse, and ecological restoration of landfill sites.

PMID:40974682 | DOI:10.1016/j.jhazmat.2025.139914

Talanta. 2025 Sep 11;298(Pt A):128832. doi: 10.1016/j.talanta.2025.128832. Online ahead of print.

ABSTRACT

Surface-enhanced Raman scattering (SERS) based on noble metal nanoparticles has garnered significant attention in analytical chemistry due to its simplicity and rapidity for low-concentration detection. Although widely applied in fields such as environmental monitoring, food safety, and biomedical diagnostics, the impact of silver nanoparticle shape on SERS performance remains insufficiently studied. Furthermore, traditional stationary solid and liquid SERS approaches are limited by inconsistent reproducibility and temporal variations in uniformity, respectively. To overcome these limitations, we introduce a simple continuous and online Ag SERS platform that employs spherical silver colloids within a capillary-Teflon tube system for dynamic, real-time analyte detection. Continuous fluid flow reduces variations in colloids, ensuring uniformity, while the enclosed system limits dynamic behaviors of colloids, enhancing stability. This platform demonstrates outstanding stability, with relative standard deviation of 2.12 %. Its versatility is showcased through the quantitative detection of melamine in milk, 6-thioguanine in serum, and histamine in beer, demonstrating its capability for accurate, real-time detection in complex matrices. This continuous and online Ag SERS platform represents a significant advancement in reliable, high-performance analyte detection, offering promising prospects for real-time analytical applications and providing a cost-effective, scalable solution for widespread use.

PMID:40972276 | DOI:10.1016/j.talanta.2025.128832

RSC Adv. 2025 Sep 10;15(39):32833-32870. doi: 10.1039/d5ra05615b. eCollection 2025 Sep 5.

ABSTRACT

Emerging contaminants (ECs), including pharmaceuticals, endocrine disruptors, heavy metals, and per- and polyfluoroalkyl substances (PFAS), are becoming increasingly crucial to identify because of their toxicity, persistence, and resistance to traditional water treatment techniques. Even if they are accurate, traditional analytical methods are frequently costly, time-consuming, and instrumentally complex. With its ease of use, quick visual reaction, high sensitivity, and affordability, colorimetric sensing based on gold nanoparticles (AuNPs) has become a viable substitute in this regard for on-site EC monitoring. The synthesis, functionalization, and use of AuNPs for the colorimetric detection of new pollutants have advanced recently, as this review illustrates. Because of their special localized surface plasmon resonance (LSPR) characteristics, AuNPs can interact with target analytes to produce noticeable color changes. We talk about different synthesis techniques, such as the reduction of citrate and borohydride, and how they affect the optical characteristics and particle shape. Additionally, we investigate functionalization techniques that provide selectivity toward ECs using thiol ligands, DNA aptamers, polymers, and chelating agents. A thorough analysis is conducted of colorimetric detection techniques, encompassing both aggregation-based and non-aggregation-based systems. Detecting ions (cation, anion), pesticides, metals (heavy metals, alkali and alkaline earth metals, coinage metals, rare-earth metals), food (formalin, melamine, rhodamine dye, etc.), pathogens, mycotoxins, oligonucleotides (DNA, nucleic acids, protein, etc.), glucose, and drugs (antibiotics, allergens, etc.) has been examined in this review. Lastly, we discuss present issues such as probe stability and matrix interference and suggest future paths for the development of portable and field-deployable sensors.

PMID:40936959 | PMC:PMC12422228 | DOI:10.1039/d5ra05615b

RSC Adv. 2025 Sep 10;15(39):32833-32870. doi: 10.1039/d5ra05615b. eCollection 2025 Sep 5.

ABSTRACT

Emerging contaminants (ECs), including pharmaceuticals, endocrine disruptors, heavy metals, and per- and polyfluoroalkyl substances (PFAS), are becoming increasingly crucial to identify because of their toxicity, persistence, and resistance to traditional water treatment techniques. Even if they are accurate, traditional analytical methods are frequently costly, time-consuming, and instrumentally complex. With its ease of use, quick visual reaction, high sensitivity, and affordability, colorimetric sensing based on gold nanoparticles (AuNPs) has become a viable substitute in this regard for on-site EC monitoring. The synthesis, functionalization, and use of AuNPs for the colorimetric detection of new pollutants have advanced recently, as this review illustrates. Because of their special localized surface plasmon resonance (LSPR) characteristics, AuNPs can interact with target analytes to produce noticeable color changes. We talk about different synthesis techniques, such as the reduction of citrate and borohydride, and how they affect the optical characteristics and particle shape. Additionally, we investigate functionalization techniques that provide selectivity toward ECs using thiol ligands, DNA aptamers, polymers, and chelating agents. A thorough analysis is conducted of colorimetric detection techniques, encompassing both aggregation-based and non-aggregation-based systems. Detecting ions (cation, anion), pesticides, metals (heavy metals, alkali and alkaline earth metals, coinage metals, rare-earth metals), food (formalin, melamine, rhodamine dye, etc.), pathogens, mycotoxins, oligonucleotides (DNA, nucleic acids, protein, etc.), glucose, and drugs (antibiotics, allergens, etc.) has been examined in this review. Lastly, we discuss present issues such as probe stability and matrix interference and suggest future paths for the development of portable and field-deployable sensors.

PMID:40936959 | PMC:PMC12422228 | DOI:10.1039/d5ra05615b

RSC Adv. 2025 Sep 10;15(39):32833-32870. doi: 10.1039/d5ra05615b. eCollection 2025 Sep 5.

ABSTRACT

Emerging contaminants (ECs), including pharmaceuticals, endocrine disruptors, heavy metals, and per- and polyfluoroalkyl substances (PFAS), are becoming increasingly crucial to identify because of their toxicity, persistence, and resistance to traditional water treatment techniques. Even if they are accurate, traditional analytical methods are frequently costly, time-consuming, and instrumentally complex. With its ease of use, quick visual reaction, high sensitivity, and affordability, colorimetric sensing based on gold nanoparticles (AuNPs) has become a viable substitute in this regard for on-site EC monitoring. The synthesis, functionalization, and use of AuNPs for the colorimetric detection of new pollutants have advanced recently, as this review illustrates. Because of their special localized surface plasmon resonance (LSPR) characteristics, AuNPs can interact with target analytes to produce noticeable color changes. We talk about different synthesis techniques, such as the reduction of citrate and borohydride, and how they affect the optical characteristics and particle shape. Additionally, we investigate functionalization techniques that provide selectivity toward ECs using thiol ligands, DNA aptamers, polymers, and chelating agents. A thorough analysis is conducted of colorimetric detection techniques, encompassing both aggregation-based and non-aggregation-based systems. Detecting ions (cation, anion), pesticides, metals (heavy metals, alkali and alkaline earth metals, coinage metals, rare-earth metals), food (formalin, melamine, rhodamine dye, etc.), pathogens, mycotoxins, oligonucleotides (DNA, nucleic acids, protein, etc.), glucose, and drugs (antibiotics, allergens, etc.) has been examined in this review. Lastly, we discuss present issues such as probe stability and matrix interference and suggest future paths for the development of portable and field-deployable sensors.

PMID:40936959 | PMC:PMC12422228 | DOI:10.1039/d5ra05615b

RSC Adv. 2025 Sep 5;15(39):32031-32040. doi: 10.1039/d5ra03280f. eCollection 2025 Sep 5.

ABSTRACT

Melamine is an additive used fraudulently to enrich foods with nitrogen, particularly in the dairy industry. It is also known as the main metabolite or degradation phytosanitary product of cyromazine. However, the numerous incidents involving living beings in aquatic environments, children and pets fed with products made from melamine in China and certain African countries have led to distrust of melamine in food. In order to ensure strong food safety and security, and good quality of the ecosystem free of melamine, it is important to design a fast, simple, reliable and efficient method for the detection of melamine. For this purpose, silver nanoparticles capped with l-cysteine functionalized carbon dots (cCDs/AgNPs) were designed for the detection of melamine. The results showed that a yellow solution of cCDs/AgNPs turns pink and gradually blue within two minutes of heating at 90 °C in the presence of melamine even at a concentration of 0.1 μg mL^-1. This color change reflects the sensitivity of cCDs/AgNPs towards melamine. The investigation of cCDs/AgNPs-based on ultraviolet-visible spectroscopy exhibits good linearity in the range from 0.5 μg mL^-1 to 4.5 μg mL^-1 for melamine detection, with a detection limit of 0.03 μg mL^-1. This method was successfully applied to determine melamine in a milk matrix, suggesting that this method can be applied for food monitoring with the aim of obtaining melamine-free food in dairy products.

PMID:40918312 | PMC:PMC12412118 | DOI:10.1039/d5ra03280f

Small Methods. 2025 Sep 2:e01445. doi: 10.1002/smtd.202501445. Online ahead of print.

ABSTRACT

The binding of small molecules to DNA may represent a mutagenic process capable of inducing genomic structural alterations and functional impairment. Melamine (MA), a toxic small molecule, exhibits a hydrogen-bonding interface structurally analogous to adenine, enabling to form non-canonical thymine-melamine (T-MA) base pairs like Watson-Crick pairing. This property allows MA to program DNA nanostructure formation. Given MA's documented biological consequences, such as kidney disease, reproductive toxicity, and central nervous system dysfunction, sensitive detection of MA-DNA interactions has become critically important. However, such subtle structural changes remain challenging to identify because of the paucity of effective detection approaches in a high-resolution manner. To overcome this limitation, nanopore measurement is employed to identify T-MA hydrogen bonding base pairing in DNA. Results demonstrate that nanopore enables unambiguous identification of T-MA hydrogen bonding via mechanically unzipping thymine-melamine-thymine (T-MA-T) triplets in DNA structures. The approach achieves single-base-pair resolution, as evidenced by nucleotide substitutions flanking the abasic site in complex DNA structures. In addition, nanopore-based kinetic analysis reveals an enhanced intramolecular stability in MA-binding DNA compared to those consisting of complete canonical DNA pairs. This research establishes a powerful platform for high-resolution interrogation of DNA-small molecule interactions and quantitative biophysical characterization of mutagenic modifications at the nanoscale.

PMID:40891541 | DOI:10.1002/smtd.202501445

Food Sci Nutr. 2025 Aug 25;13(9):e70831. doi: 10.1002/fsn3.70831. eCollection 2025 Sep.

ABSTRACT

Melamine (MEL) and cyanuric acid (CYA) are contaminants that can enter the human body through dietary sources, raising significant toxicological concerns, particularly for infants. MEL undergoes minimal biotransformation in the human body. While breast milk is widely recognized as the optimal source of nutrition for infants, it may also serve as a potential route for the transmission of contaminants. This study aimed to quantify the concentrations of MEL and CYA in breast milk and assess the associated non-carcinogenic toxicity risks for infants aged 0-6 months. A total of 100 mothers from Hamadan, Iran, who exclusively breastfed their infants aged 15-150 days, were included. Breast milk samples, ranging from 10 to 50 mL, were manually expressed. The results revealed that 77% of the samples contained MEL, while 84% contained CYA, both exceeding the detection limits. The average concentrations of MEL and CYA were 730 ± 26 and 400 ± 38 ng mL^-1, respectively. Risk assessment indicated that none of the infant groups exhibited a hazard quotient (HQ) or cumulative risk (hazard index) from MEL and CYA exposure. According to Monte Carlo simulation, the 95th percentile of HQ for MEL and CYA in breast milk were 0.00561 and 0.0000154, respectively, both well below the safety threshold (HQ < 1). These findings suggest that breast milk consumption by infants up to 6 months of age in Hamadan does not pose a significant risk in terms of MEL and CYA exposure.

PMID:40873966 | PMC:PMC12378073 | DOI:10.1002/fsn3.70831

J Hazard Mater. 2025 Oct 5;497:139514. doi: 10.1016/j.jhazmat.2025.139514. Epub 2025 Aug 18.

ABSTRACT

Previous studies have found that melamine tableware workers are exposed to high levels of airborne melamine, which is linked to increased urinary markers of oxidative stress and kidney injury. However, the effectiveness of engineering controls in reducing such exposures had not been evaluated. To address this, an intervention was conducted in October 2016, installing two local exhaust systems combined with airflow containment curtains and a large open-end fan in high-exposure areas. Twenty-two workers were monitored before (March-April 2016) and after the intervention (November 2016). A total of 1834 air and urine samples were collected and analyzed. After the intervention, median personal melamine concentrations dropped from 159.12 to 4.51 µg/m³ (p < 0.0001), and formaldehyde levels declined from 215.99 to 162.16 µg/m³ (p = 0.002), representing 97.2 % and 24.6 % reductions, respectively. Generalized estimating equation models revealed significant decreases in diurnal urinary melamine (β = -7.02; p = 0.043) and MDA (β = -0.47; p < 0.001), though the reduction in 8-OHdG was not statistically significant (β = -0.34; p = 0.074). These results suggest that our engineering installations are effective in reducing airborne melamine exposure and short-term oxidative stress, though further research is needed to evaluate long-term health effects.

PMID:40865217 | DOI:10.1016/j.jhazmat.2025.139514

Food Chem. 2025 Nov 30;493(Pt 4):145933. doi: 10.1016/j.foodchem.2025.145933. Epub 2025 Aug 13.

ABSTRACT

Malachite green (MG) is a toxic contaminant commonly found in aquaculture, making its effective removal and detection crucially important. In this study, MIL-100(Fe) was synthesized via a microwave-assisted hydrothermal method under optimized conditions (150 °C, 200 W, 30 min; FeCl₃·6H₂O:H₃BTC = 2:3). The resulting material exhibited excellent structural stability, a high specific surface area (1169.9 m²/g), and a remarkable MG adsorption capacity of 714.29 mg/g. To enable practical application and reusability, MIL-100(Fe) was immobilized onto a melamine sponge (MeS) using polyvinylidene fluoride (PVDF) as binding agent, forming a recyclable MeS/PVDF/MOF composite. When applied for solid-phase extraction of MG in conjunction with UV detection, the composite demonstrated high recovery rates (92.1-99.4 %), a low detection limit (2.29 μg/L), and consistent performance with over 80 % recovery after six reuse cycles in both real fish and wastewater samples. This study presents a simple, efficient and sustainable strategy for the adsorption and detection of MG in aquatic food matrices.

PMID:40848346 | DOI:10.1016/j.foodchem.2025.145933

Data Brief. 2025 Aug 6;62:111965. doi: 10.1016/j.dib.2025.111965. eCollection 2025 Oct.

ABSTRACT

Wood based panels are widely used in construction and furniture due to their cost effectiveness, sustainability, and processability. However, adhesives and additives used in these engineered materials may release volatile organic compounds (VOCs), including formaldehyde and BTEX compounds, affecting indoor air quality. This study presents a dataset examining VOC emissions from three commonly used panels: pine wood board (PWB), low pressure melamine particleboard (LPM), and particleboard (PB), and their potential health impacts in mice. To reflect a real-life early-phase exposure scenario, the panels were not pre-conditioned and were installed on three sides of a 50 × 50 × 50 cm acrylic chamber with passive air exchange only. Air samples were collected nine times over 14 days using automatic thermal desorption gas chromatography/mass spectrometry (ATD GC MS). VOCs were categorized as total VOCs (TVOC), natural VOCs (NVOC), five hazardous VOCs (BTEX plus styrene; 5VOC), and formaldehyde. Male BALB/c mice (n = 4 per group) were continuously exposed to each chamber for 14 days. Body weight was monitored on days 7 and 14, and 21 hematological and serum biochemical parameters were analyzed after exposure. Organs including the liver, kidney, lung, heart, and spleen were weighed and histologically examined. The dataset includes time resolved emission profiles for each panel type, longitudinal body weight measurements, blood and serum biochemical markers, and histological images. VOC emissions varied by material, with detectable formaldehyde in LPM and PB, and predominantly NVOC in PWB. No abnormal behaviors were observed during exposure. Statistically significant differences were noted in some blood parameters and organ weights between control and exposed groups, although all values remained within the normal physiological range. Histopathological analysis likewise revealed no specific abnormalities. This dataset supports future studies on VOC exposure response modeling, regulatory benchmarking, or risk mitigation strategies and contributes to understanding acute biological responses to real world wood panel emissions.

PMID:40837475 | PMC:PMC12361599 | DOI:10.1016/j.dib.2025.111965

Water Res. 2025 Aug 7;287(Pt A):124366. doi: 10.1016/j.watres.2025.124366. Online ahead of print.

ABSTRACT

Tire additives and their transformation products (TATPs) are increasingly recognized for their toxicity and widespread environmental presence. However, the interplay of rainfall, seasonal variation, and stream type in governing their multi-media partitioning and risks remains largely unexplored. This study investigated the spatiotemporal distribution, environmental drivers, and ecological risks of 21 TATPs in three distinct urban streams (general road, expressway, and rural road-adjacent). Seventeen, 19, and 14 TATPs were quantified in water (514-6541 ng/L), suspended particulate matter (SPM, 12.8-244 ng/L), and sediment (1.71-248 ng/g), respectively. Rainfall significantly altered aqueous TATP levels, while stream type and seasonal variation influenced TATP pollution in SPM and sediment. Multiple linear regression identified pH, temperature, and road area as key aqueous-phase drivers, whereas precipitation and road area controlled the levels of TATPs in SPM and sediment, respectively. Hydrophobicity was a key determinant in TATP multi-media partitioning. High ecological risks were found across all water samples, primarily associated with 1,3-diphenylurea (DPU), 1,3-dicyclohexylurea (DCU), N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPD-Q), and hexa(methoxymethyl)melamine (HMMM). Eight TATPs exhibited persistence, bioaccumulation, or toxicity traits, warranting prioritized regulation. These insights are crucial for crafting effective environmental policies to mitigate =TATP impacts and protect urban aquatic ecosystems.

PMID:40819446 | DOI:10.1016/j.watres.2025.124366

J Chromatogr A. 2025 Oct 11;1760:466280. doi: 10.1016/j.chroma.2025.466280. Epub 2025 Aug 9.

ABSTRACT

Melamine-formaldehyde resins are used in various industrial applications. As melamine is a toxic compound on the candidate list of Substances of Very High Concern, its content in melamine-based resins is important. Here we present two high-performance liquid chromatography methods suitable for the determination of free melamine content in uncured non-ionic and negatively charged melamine-based resins. A gradient reversed-phase liquid chromatography method using a C18 column was developed for the determination of free melamine content in non-ionic resins, while an isocratic mixed-mode liquid chromatography method using a Primesep 100 column was developed for the quantification of free melamine in sulfonated melamine-based resins. Both methods utilise ultraviolet detection, which allows the quantification of melamine in melamine-based resins with a limit of quantification of ∼10^-3% by weight and good repeatability and linearity over a wide range of melamine concentrations.

PMID:40818432 | DOI:10.1016/j.chroma.2025.466280

Aquat Toxicol. 2025 Oct;287:107537. doi: 10.1016/j.aquatox.2025.107537. Epub 2025 Aug 10.

ABSTRACT

Concerns over plastic-associated chemical toxicity are increasing amid the plastic pollution crisis. Halogenated flame retardants, though effective in plastic development, are being phased out due to toxicity, while nitrogen-based alternatives, such as melamine cyanurate (MC), are considered more chemically stable and less toxic. Here, we assess the solubility and chemical stability of MC in freshwater using various solvents and evaluate degradation after UV exposure. Additionally, we compare the acute and chronic aquatic toxicity of MC to the more widespread halogenated flame retardant tetrabromophthalic anhydride (TBA) using the Daphnia magna invertebrate model. Toxicity of a common solvent, dimethyl sulfoxide (DMSO), was also assessed. MC was insoluble in 16 of 18 tested solvents, with solubility only seen in a strong acid and base. UV exposure for 72 h within freshwater media indicated minimal degradation, classifying MC as a highly stable compound. Acute toxicity tests at 1-20 mg/L showed no significant difference in EC₅₀ values between TBA (0.16 - 11.46 mg/L) and MC (5.91 - 13.23 mg/L). Chronic toxicity tests at 0.5, 5, and 15 mg/L yielded NOEC values of ≤5 mg/L for TBA and <5 mg/L for MC. At 15 mg/L, chronic exposure to TBA, MC, and DMSO resulted in 100% mortality in D. magna. These findings challenge the assumption that DMSO is a low-toxicity solvent in aquatic testing. Overall, the study highlights the difficulty in assessing the toxicity of highly stable flame retardants like MC, while indicating that they may exhibit similar aquatic toxicity as halogenated congeners.

PMID:40816006 | DOI:10.1016/j.aquatox.2025.107537

Appl Opt. 2025 Jul 10;64(20):5852-5859. doi: 10.1364/AO.561321.

ABSTRACT

Milk adulteration through dilution and the addition of nitrogen-rich chemicals is a persistent issue in the dairy industry, affecting product quality and consumer safety. Current monitoring techniques often rely on protein nitrogen content, which can be misrepresented by these additives. We report a reflective holographic sensor that can directly detect diluted milk by monitoring the shrinkage of the holographic grating, which induces a rapid and reversible blue shift of 34 nm across milk dilutions ranging from 10 to 100 vol%. The holographic milk sensor demonstrates high selectivity, remaining unaffected by variations in fat content, ionic strength, or pH. Testing with various casein suspensions reveals that the shrinkage effect is specifically triggered by calcium caseinate micelles, in marked contrast to free casein slurries in water. Moreover, adding melamine to artificially compensate for the nitrogen loss in diluted milk results in swelling rather than contraction. This holographic sensor offers a reliable and effective tool for quality control in the dairy industry.

PMID:40793746 | DOI:10.1364/AO.561321

Spectrochim Acta A Mol Biomol Spectrosc. 2026 Jan 5;344(Pt 2):126751. doi: 10.1016/j.saa.2025.126751. Epub 2025 Jul 29.

ABSTRACT

Melamine contamination from illegal additives, packaging contaminants, and pesticide residues threatens dairy product safety, demanding rapid detection. Traditional methods such as chromatography or mass spectrometry are precise but lack field applicability due to complexity, time consumption, and cost. Surface-enhanced Raman spectroscopy (SERS) is a promising alternative for sensitive, rapid, and label-free analysis. However, current SERS implementations face challenges like complex substrate synthesis, environmentally harmful sample processing, and lack of discrimination of analogues. Thus, developing a simple SERS-based method for detecting melamine and its analogues without pretreatment remains urgent. In this paper, a straightforward SERS detection method is proposed to achieve accurate and rapid pretreatment-free detection of melamine in milk. Polytetrafluoroethylene‑silver nanospheres (PTFE-AgNPs) SERS substrate is fabricated by mixing silver colloid, sodium hydroxide and sodium chloride solution, followed by deposition onto a PTFE filter membrane by filter-pressing assembly. Additionally, diluted milk is subjected to SERS testing directly without any pretreatment. Furthermore, both qualitative and quantitative analyses were performed using RF, PCA-SVM and CNN. Among the three algorithms, CNN classification model achieved the best accuracy 99.25 % for distinguishing melamine, ammeline, ammelide, and blank controls, while the CNN regression model yielded a coefficient of determination (R²) of 0.9999 for melamine quantification. The limit of detection (LOD) for melamine in milk was 3.32 × 10^-6 M, lower than the World Health Organization (WHO) recommended limit. This method, featuring simple SERS substrate preparation and non-pretreatment, enables rapid and efficient detection of melamine and its analogues, promoting broader applications of SERS in food safety monitoring.

PMID:40749506 | DOI:10.1016/j.saa.2025.126751

Langmuir. 2025 Aug 12;41(31):21144-21160. doi: 10.1021/acs.langmuir.5c03079. Epub 2025 Jul 29.

ABSTRACT

Carbon nitride (g-C₃N₄, CN) is always used as a metal-free catalyst to activate peroxymonosulfate (PMS) without toxic metal ion leaching in solutions. However, it is still a challenge to enhance the catalytic activity for CN. Herein, sulfur (S)-doped g-C₃N₄ is synthesized by a facile method as named CNS_x, where x represents the mass ratio of ammonium sulfate to melamine during the CNS_x synthesis. Partial N atoms such as pyridinic N in CN were replaced by S atoms. CNS_1.75 exhibited an excellent catalytic activity to degrade Rhodamine B (RhB) via PMS activation under the assistance of the visible light (Vis). The rate constant (k) increased about 9 and 7 times for CNS_1.75/Vis/PMS than that of CNS_1.75/PMS and CNS/Vis/PMS systems. Moreover, the k value is higher than that of some metal-doped CN as reported. The toxicity of RhB was effectively reduced after the degradation process with the total organic carbon (TOC) removal ratio 48% after 40 min. The RhB removal efficiency kept 95% after continuous operation for 12 h. The catalytic mechanism was proposed in which ¹O₂ was the dominant reactive oxygen species (ROS).

PMID:40726166 | DOI:10.1021/acs.langmuir.5c03079

Environ Sci Technol. 2025 Aug 12;59(31):16282-16292. doi: 10.1021/acs.est.5c03579. Epub 2025 Jul 28.

ABSTRACT

Melamine (MEL) and its derivatives are known for acute nephrotoxicity, but the risks from chronic exposure and underlying mechanisms of toxicity are unclear. We integrated environmental monitoring (356 pairs of house dust and urine samples collected across mainland China) with cell-based bioassays to investigate MEL exposure sources and toxic effects. MEL-related chemicals were frequently detected in dust (median: 10.3 μg/g) and urine (22.3 ng/mL) samples, indicating their widespread presence in indoor environments and chronic exposure among the Chinese population. Significant positive correlations were observed between MEL-related chemicals and neutrophil gelatinase-associated lipocalin (NGAL), a urinary biomarker of nephrotoxicity. RNA-sequencing of MEL-exposed human kidney-2 (HK-2) cells revealed significant enrichment of the ferroptosis signaling pathway. Further bioassays demonstrated that MEL exposure induces iron-driven mitochondrial lipid peroxidation in HK-2 cells. The system X_c^-/GPX4, ACSL4, and TFR1/DMT1 pathways identified as potential targets in ferroptosis-mediated early renal injury in both acute toxicity experiments and chronic exposure to environmentally relevant concentrations. This finding was further supported by urinary malondialdehyde and Fe²⁺ levels that mediated 13-31% of the effect of MEL-related chemicals on NGAL in humans. Our study provides valuable insights into the role of ferroptosis in chronic kidney injury associated with environmental exposure to MEL and its derivatives.

PMID:40719558 | DOI:10.1021/acs.est.5c03579

Mikrochim Acta. 2025 Jul 28;192(8):531. doi: 10.1007/s00604-025-07422-4.

ABSTRACT

A novel ratiometric fluorescent probe was developed by combining terbium-doped boron/nitrogen co-doped carbon dots (Tb@BNCDs) with thiolated-protected gold nanoclusters (Th@Au NCs) for efficient melamine detection based on a competitive coordination mechanism. The designed system exploits the synergistic effects of aggregation-induced emission (AIE) and Förster resonance energy transfer (FRET) processes. The Tb@BNCDs, formed via coordination of Tb³⁺ ions with the amino and carboxyl groups on BNCDs, serve as both a stable fluorescence source and a coordination site for melamine interaction. Simultaneously, the weakly emissive Th@Au NCs were activated through Tb³⁺-induced aggregation, yielding a hybrid nanostructure exhibiting dual emission peaks at 470 nm and 630 nm. Upon the introduction of melamine, competitive binding to Tb³⁺ ions occurs via melamine's nitrogen-rich triazine structure, disrupting the original coordination complexes. This displacement interferes with AIE and FRET pathways, resulting in quantifiable changes in fluorescence emission intensity ratios (F₄₇₀/F₆₃₀), and enabling ratiometric detection. The probe demonstrates a broad linear detection range (0.01-300 µM), an ultra-low limit of detection (LOD) of 2.6 nM, and rapid response time (~ 1.5 min), outperforming many existing single-signal fluorescent systems. Stability assessments confirmed robust optical performance under varying pH, ionic strength, and UV exposure conditions, though long-term storage stability remains to be evaluated. The probe's high selectivity for melamine was validated against common food matrix interferents. Furthermore, practical applicability was demonstrated by analyzing spiked milk and infant formula samples, yielding satisfactory recoveries and precision, comparable to standard HPLC/UV methods. Overall, this ratiometric fluorescence platform offers a sensitive, rapid, and user-friendly approach for melamine monitoring, with potential for adaptation to other food safety applications through surface modification or doping strategies.

PMID:40719877 | DOI:10.1007/s00604-025-07422-4

J Chromatogr A. 2025 Sep 27;1759:466230. doi: 10.1016/j.chroma.2025.466230. Epub 2025 Jul 17.

ABSTRACT

A novel adsorbent named as MS@CTFs, was successfully synthesized through the Schiff base reaction by immobilizing a covalent triazine framework (CTF) constructed from 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TAPT) and trimethylformyl resorcinol (TP) onto a melamine sponge (MS) substrate. The innovative design integrated robust triazine-based CTF with an easy-to-use melamine sponge, simplifying the sample preparation procedure and also enhancing the adsorption performance. After optimizing the adsorption parameters, the MS@CTFs demonstrated robust adsorption for enrofloxacin (ENR) from milk matrices, the adsorption capacity was 155.3 mg g^-1. the LOD and LOQ were determined to be 0.032 μg mL^-1 and 0.107 μg mL^-1, respectively. Assessments conducted via GAPI, Complex GAPI, AGREE, and AGREEprep evaluation frameworks validated the method's outstanding environmental sustainability and operational feasibility with AGREE score of 0.67, AGREEprep score of 0.66. Furthermore, the MS@CTFs exhibited highly selective affinity towards cationic dyes. This study underscores the potential of the MS@CTFs as a selective adsorbent with nearly 100 % removal efficiency for the removal of ENR and cationic dyes from aqueous environments, contributing to advancements in milk and water treatment technologies.

PMID:40712455 | DOI:10.1016/j.chroma.2025.466230

J Environ Manage. 2025 Sep;391:126647. doi: 10.1016/j.jenvman.2025.126647. Epub 2025 Jul 19.

ABSTRACT

The challenge of recovering conventional photocatalysts has been addressed by the development of floating variants. However, the underlying molecular mechanisms governing the photocatalytic inactivation of hazardous algae remain poorly understood. This study employed a floating photocatalyst, melamine sponge-loaded bismuth trioxide coupled copper metal-organic framework (MS/Bi₂O₃@Cu-MOF), to efficiently inactivate a representative marine toxic alga, Karenia mikimotoi (K. mikimotoi), under visible light irradiation. Concurrently, Data-Independent Acquisition (DIA) proteomics was systematically applied to investigate differential protein expression throughout the photocatalytic inactivation process. At a loading amount of 0.4 g, an inactivation rate of K. mikimotoi reaching 99.306 % was achieved within 12 h. The MS/Bi₂O₃@Cu-MOF treatment group exhibited significant reductions in the three primary photosynthetic pigments and soluble protein. Furthermore, the relative content of reactive oxygen species (ROS) peaked at 681.45 % at 3 h before declining. Conversely, the specific activities of three key antioxidant enzymes demonstrated substantial increases. Differential protein enrichment analysis revealed that photocatalysis primarily affected the expression of proteins in K. mikimotoi associated with superoxide dismutase (SOD), peroxidase (POD), as well as proteins involved in calcium and potassium ion binding/transport and phospholipid binding. Gene ontology (GO) enrichment analysis revealed that the predominant functional category among the differentially expressed proteins (DEPs) was associated with metal ion binding. Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis further identified significant involvement of these DEPs in photosynthetic processes within K. mikimotoi. Collectively, this study provides an experimental foundation and theoretical insights at the protein level for understanding the photocatalytic inactivation of harmful algae, offering practical insights for advancing photocatalytic technology in real-world applications.

PMID:40684592 | DOI:10.1016/j.jenvman.2025.126647

Anal Methods. 2025 Jul 24;17(29):6133-6141. doi: 10.1039/d5ay00765h.

ABSTRACT

Melamine (MEL) is frequently adulterated in dairy products to manipulate protein content test results due to its high nitrogen content. In this study, a fluorescent probe based on ofloxacin (OFL) and gold nanoparticles (AuNPs) was proposed for the specific and sensitive detection of MEL. In the pH range of 4.5-7.5, the fluorescence spectrum of OFL exhibits a high degree of overlap with the absorption spectrum of AuNPs, and interactions based on fluorescence resonance energy transfer (FRET) occur, with significant quenching of OFL fluorescence accompanied by a change in fluorescence lifetime. After being incorporated into MEL, the amino group of MEL specifically interacted with the surface of AuNPs through coordination. This interaction triggered the aggregation of AuNPs, which in turn led to the fluorescence recovery of OFL. The detection of melamine was accomplished by quantifying the change in fluorescence intensity of OFL. Under optimized conditions, the MEL concentration exhibited a strong linear relationship with the relative fluorescence intensity of the probe (R² = 0.994) within a range of 0.1 to 1.6 μM. The limit of detection was determined to be 7.28 nM. It is noteworthy that the method was validated in real milk samples, with recovery rates ranging from 98.2% to 107.1%. The method exhibits excellent selectivity and sensitivity for MEL, making it a suitable tool for the environmental detection of milk.

PMID:40663392 | DOI:10.1039/d5ay00765h

Food Chem. 2025 Nov 15;492(Pt 2):145466. doi: 10.1016/j.foodchem.2025.145466. Epub 2025 Jul 7.

ABSTRACT

Melamine, a nitrogen-rich industrial compound, is often illegally added to food products-especially dairy, to artificially inflate protein content, posing serious health risks such as kidney damage upon long-term exposure. This study aims to develop a fluorescence-based sensor for the sensitive detection of melamine. Nitrogen-doped carbon quantum dots (N-CQDs) were synthesized using Murraya koenigii leaves via a green, microwave-assisted method. Resulting N-CQDs exhibited a high fluorescence-quantum-yield of 30 %, and their structural and optical characteristics were thoroughly analysed using appropriate techniques. Detection mechanism is based on dynamic fluorescence quenching, allowing for highly responsive melamine-sensing with a low detection limit of 0.385 μM. When applied to real samples like water and milk, sensor demonstrated excellent performance, achieving recovery rates between 96.8 % and 101.8 % with low relative standard deviations (0.70 %-4.34 %). Results suggest that developed sensor is a promising tool for rapid, green, and sensitive detection of melamine in food safety and environmental monitoring.

PMID:40645049 | DOI:10.1016/j.foodchem.2025.145466

Environ Health. 2025 Jul 9;24(1):47. doi: 10.1186/s12940-025-01201-7.

ABSTRACT

Pregnant women are regularly exposed to a variety of environmental toxicants in daily life, posing a potential threat of kidney injury before presence of clinical manifestations. As there is a paucity of studies employing an exposome-based approach of kidney health in pregnant women, this study utilizes the above-mentioned strategy to identify the most significant environmental toxicants associated with early kidney injury in pregnant women in the cohort of TMICS (Taiwan Maternal and Infant Cohort Study). A total of 1,139 third-trimester pregnant women (weeks 29-40) were recruited between 2012 and 2015, and one-spot urine samples were successfully collected for study. Sixteen biomonitoring chemicals were measured in urine, including exposure measurements of melamine, 9 phthalate metabolites, nonylphenol (NP), bisphenol A (BPA), methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP), and outcome measurements of NAG (N-acetyl-β-d-glucosaminidase) and albumin-to-creatinine ratio (ACR). A two-tier strategy of statistical analyses was employed and data was randomly and evenly split to both training (n = 569) and validation (n = 570) sets. Using a weighted quantile sum (WQS) regression in the training set and subsequently a multivariate regression in the validation set, we found that NP was the most important chemical to link with early markers of kidney injury, both ACR and NAG. Our findings indicate that short-term exposure to NP is associated with markers of subclinical kidney injury in pregnant women in Taiwan. Further research is warranted to determine whether NP exposure is linked to clinically relevant kidney outcomes.

PMID:40635015 | PMC:PMC12243187 | DOI:10.1186/s12940-025-01201-7

Food Chem X. 2025 Jun 13;29:102663. doi: 10.1016/j.fochx.2025.102663. eCollection 2025 Jul.

ABSTRACT

Plant-based materials are increasing been used as an alternative to conventional plastic materials in food packaging applications. Thus, for example, bamboo-based food contact articles are gaining popularity owing to their environmentally friendly connotations. However, the evaluation of its safety has been barely addressed. Components of these materials can migrate into the food leading to consumer exposure. Their identification is key for risk evaluations. In the present study, the chemical composition of a great variety of bamboo-based food contact articles including plates, chopsticks, etc. was explored. The volatile and semi-volatile fractions were analysed by gas chromatography-mass spectrometry (GC-MS). Volatile components were concentrated in a Purge & Trap system and semi-volatile compounds were analysed after a methanol extraction. A great diversity of compounds was tentatively identified, some considered toxic (e.g., 5-hydroxymethylfurfural). In addition, a sample suspected of containing melamine was analysed by LC-MS and melamine and its derivatives were detected.

PMID:40599599 | PMC:PMC12212174 | DOI:10.1016/j.fochx.2025.102663

Carbohydr Polym. 2025 Jul 15;360:123598. doi: 10.1016/j.carbpol.2025.123598. Epub 2025 Apr 11.

ABSTRACT

Polyamide 66 (PA66), a key polymer in numerous industries, struggles with fire resistance in world spread, emitting toxic gases, smoke, and molten drips, with mechanical properties constrained by required high loading. Herein, we designed a flower-like bio-based three-hybrid flame retardant, synthesized cellulose nanocrystals (CNC) with melamine polyphosphate (MPP) and zinc borate (ZB) through successive grafting and electrostatic adsorption processes. This innovative fire-extinguish composite forms spherical arrangement structure within PA66, and noncombustible gas and protective phase on exposure to fire, significantly enhancing PA66's flame retardancy, mechanical properties, and UV resistance. Incorporating 15 wt% flame retardant, the PA66 composite remarkably improves LOI to 28.7 % and V-0, and reduces peak heat release rate to 210.56 kW/m², 75 % lower than neat PA66. Surprisingly, its mechanical properties were substantially improved with a 225 % and 317 % increase in tensile stress and tensile strain, respectively. This strategy has the potential to establish a fire-safe and highly efficient application environment for PA66, thereby ensuring the protection of human life and property.

PMID:40399011 | DOI:10.1016/j.carbpol.2025.123598

Int J Environ Health Res. 2025 May 18:1-14. doi: 10.1080/09603123.2025.2503475. Online ahead of print.

ABSTRACT

This study investigated the relationship between maternal behaviours, environmental exposures, and the levels of melamine and bisphenols (BPs), including bisphenol F (BPF), bisphenol A-F (BPAF), and bisphenol S (BPS), in breast milk. Mothers provided information on cosmetic use, food packaging, and dietary habits, while breast milk samples were analyzed using high-performance liquid chromatography. BPAF, BPS, and BPF were detected in 32.3%, 33.8%, and 20% of samples, respectively, while melamine was present in all samples (mean: 32.3 ± 16.7 ng/mL). Seven samples (10.8%) contained all three BPs, while 49.2% had none. Higher BPAF and BPF levels were observed in breast milk from mothers aged 30-34. Makeup use was associated with elevated BPAF levels (p = 0.013), while sunscreen use was correlated with increased BPF (p = 0.040) and melamine (p = 0.010) levels. Storing oil in plastic containers was linked to higher BPS levels. These findings suggest that maternal exposure to personal care products and food packaging materials significantly influences BPs and melamine levels in breast milk. The results highlight the importance of considering both behavioural and environmental factors when assessing chemical exposure during breastfeeding. Further research is needed to understand the long-term effects of these exposures on infant health.

PMID:40383959 | DOI:10.1080/09603123.2025.2503475

Mikrochim Acta. 2025 May 14;192(6):352. doi: 10.1007/s00604-025-07209-7.

ABSTRACT

This study presents the first demonstration of a photothermal-based paper analytical device (PT-PAD) for melamine monitoring in milk samples. The sensor utilizes plasmonic gold nanoparticles (AuNPs) as effective photothermal materials to enable melamine detection. In our technique, melamine induces the aggregation of AuNPs on the paper substrate, resulting in a temperature change proportional to melamine levels. This temperature variation can be measured using a portable and inexpensive thermometer, enhancing affordability. The sensor provides a linear range between 125.0 and 1500.0 ng mL^-1 with a R² value of 0.9965 and a detection limit of 27.0 pg mL^-1. It demonstrates excellent selectivity with no observed interference, and achieves high accuracy and precision in real milk samples, with recoveries between 97.3 and 108.5% and a maximum RSD of 7.5%. The results are statistically comparable to HPLC, confirming the method's reliability. Furthermore, while the assay requires only low-cost commercial tools such as a laser pointer and a thermometer, its detection efficiency is significantly higher than other previous PAD methods for melamine detection. Overall, our developed PT-PAD sensor is well-suited for monitoring melamine levels in milk samples, offering advantages such as affordability, sensitivity, and ease of use. The approach also presents a promising platform for future expansion into other analytes by integrating plasmonic nanomaterials with microfluidic technologies, broadening its application across food safety and environmental monitoring.

PMID:40366462 | DOI:10.1007/s00604-025-07209-7

Food Chem Toxicol. 2025 Aug;202:115521. doi: 10.1016/j.fct.2025.115521. Epub 2025 May 5.

ABSTRACT

Dairy products are exceptionally nutritious and a key component of our diet. They are utilized in a wide range of food industries due to their significance. However, being highly popular and valuable, they are among the most common products subject to adulteration. Melamine is a chemical compound deliberately added to various food products. It is used to artificially increase the apparent protein content in milk, milk powder, pet food, and other foods. In this study, pure milk powder along with 12 different types of adulterated samples (with melamine content of 1, 2, 3, 4, and 5 ppm) in both dry and wet forms was analyzed using an electronic nose equipped with 8 metal oxide sensors to detect adulteration patterns. Principal Component Analysis (PCA), discriminant analysis (DA), and Support Vector Machine (SVM) methods were employed to analyze sensor response patterns and classification. Quantitative Descriptive Analysis (QDA) yielded a precision of 99.5 %, while Multi-Discriminant Analysis (MDA) achieved a precision of 98.5 %. Therefore, it appears that electronic nose technology with metal oxide sensors, along with chemometric methods, can be a truly effective tool for the rapid detection and classification of pure milk powder from adulterated materials.

PMID:40334969 | DOI:10.1016/j.fct.2025.115521

Crit Rev Anal Chem. 2025 Apr 29:1-13. doi: 10.1080/10408347.2025.2496502. Online ahead of print.

ABSTRACT

Proteins contain amino acids, which are extremely important for healthy growth, muscle mass production, and improved quality of life. As a result, consumers' intake of insufficient amounts of protein, leads to a deterioration in body resistance, becoming vulnerable to diseases, muscle mass loss, and experiencing many adverse health conditions. It is more commonly used by athletes, particularly to enhance and speed up weight gain, and it is crucial for kids, the elderly, and patients who need to replace absent nutrients in their diet. As more people use protein powder supplements, sales are becoming more competitive, and numerous unauthorized producers have begun providing products that meet the need. Many protein supplements on the market are adulterated or contain undisclosed, inexpensive chemicals, causing discrepancies between labeled and actual amounts of active compounds, which is a growing issue. These include substances like rice, soybeans, urea, cheaper amino acids (e.g. L-glutamine and L-taurine), bulking agents like maltodextrin and cyanuric acid and, in some cases, even dilution with milk powder or melamine. It may be able to better regulate athletes' and patients' exposure to illegal substances and adulteration, safeguard the health of consumers by developing quick and precise ways to test protein supplements. This comprehensive review presents a variety of analytical approaches utilizing spectroscopic and chromatographic methods for the identification of additives for quality control and content verification purposes.

PMID:40300048 | DOI:10.1080/10408347.2025.2496502

Crit Rev Anal Chem. 2025 Apr 14:1-32. doi: 10.1080/10408347.2025.2477535. Online ahead of print.

ABSTRACT

Milk adulteration is a crucial worldwide concern that endangers food safety and public health, as it involves the deliberate tampering with milk by adding foreign substances or removing essential nutrients, often to boost profits or hinder microbial growth. Traditional detection methods frequently lack the sensitivity and speed required to identify adulterants within milk's complex matrix. This systematic review critically examines the application of spectroscopic techniques for detecting milk adulteration, focusing on Nuclear Magnetic Resonance (NMR), Infrared (IR) Spectroscopy, Raman Spectroscopy, Ultraviolet-Visible (UV-Vis) Spectroscopy, Mass Spectrometry, Laser-Based Techniques, Dielectric Spectroscopy, and X-Ray Spectroscopy. Each technique's principles, advantages, limitations, and specific applications in identifying adulterants, such as water, urea, melamine, added sugars, fats, preservatives, and heavy metals are discussed. The review highlights how these methods offer rapid, non-destructive, and sensitive analysis, enhancing the ability to detect adulterants at molecular levels. Despite advancements, challenges persist, including the complexity and natural variability of milk composition, high costs of advanced equipment, need for specialized expertise, and lack of standardized protocols. Future directions emphasize developing portable and cost-effective spectroscopic devices, integrating artificial intelligence and machine learning for advanced data analysis, and fostering international collaboration to establish standardized methodologies and comprehensive spectral databases. By addressing these challenges, spectroscopic techniques can be more widely implemented, ultimately safeguarding public health, ensuring the integrity of dairy products, and maintaining consumer trust in the global food supply chain.

PMID:40227776 | DOI:10.1080/10408347.2025.2477535

Spectrochim Acta A Mol Biomol Spectrosc. 2025 Oct 5;338:126156. doi: 10.1016/j.saa.2025.126156. Epub 2025 Apr 1.

ABSTRACT

We present a novel, cost-effective SERS substrate for melamine detection in milk. Melamine is a nitrogen-rich compound illegally used to indicate high protein content. We developed a hybrid substrate based on molecularly imprinted polymer nanobeads functionalized with graphene oxide (MIP nanobeads@fGO). MIPs act as a door for selective detection and provide chemical enhancement. fGO achieves further chemical enhancement of the Raman signal by bond-making through functionalized moieties and electrostatic interaction with the ring moiety of fGO with melamine in SERS. Prior to polymerization, the molecular interaction between vinyl imidazole (VIM) as a functional monomer and melamine as a target molecule was modeled using AutoDockTools GUI (Graphical User Interface) and AutoGrid for molecular modelling simulations and grid calculations. From the clustering histogram, melamine and VIM molecules had the lowest binding energy of -0.77 kcal/mol. Also, the free energy of Melamine-VIM interaction at 298.15 K was -2729.21 kcal/mol, which is evidence that the interaction was energetically favorable. The fGO and MIP nanobeads@fGO were characterized by various techniques including FTIR and RAMAN spectroscopy, DSL and SEM. The SERS performance of MIP nanobeads@fGO was analyzed and showed excellent performance towards melamine with an EF of 1.3 × 10⁶ and good reproducibility with an RSD of 8.3 %. A good correlation was observed between the -log concentration of melamine (μM) and the Raman intensity (a.u.) in a broad linear range from 7.9 E-5 μM to 7.9 E2 μM, with LOD and LOQ of 1.2 μM (0.15 ppm) and 3.6 μM (0.45 ppm), respectively. The USFDA and WHO introduced the tolerable level of melamine in milk and dairy products at no >2.5 ppm. Our LOD is below the tolerable limit, indicating that the MIP nanobeads@fGO substrate can be effectively used for food safety analysis in milk samples.

PMID:40209451 | DOI:10.1016/j.saa.2025.126156

Environ Pollut. 2025 Jun 1;374:126206. doi: 10.1016/j.envpol.2025.126206. Epub 2025 Apr 8.

ABSTRACT

Studies concerning the effect of co-exposure to melamine and phthalates on kidney function in children are rare. Thus, this study examines the above-mentioned relationship and their sex-different effect. Whether the exposure of the two chemicals from their mothers, when children were in the womb during the third trimester, affected renal injury markers in children afterwards is also examined. This study was from Taiwan Maternal and Infant Cohort Study cohort established in October 2012 to enroll third-trimester pregnant mothers up to May 2015. Their offspring were subsequently recruited between 2016 and 2020 as our study children. One-spot urine specimens were collected from both pregnant mothers (2012-2015) and study children (2016-2020) for the simultaneous measurement of melamine and 11 phthalate metabolites. Daily intakes of melamine and five phthalates, including DEHP (di-2-ethylhexylphthalate), DiBP (Dibutyl phthalate), DnBP (Di-n-butyl phthalate), BBzP (Butyl benzyl phthalate), and DEP (Diethyl phthalate), were estimated using a creatinine excretion-based model in both study children and their mothers. Two early markers of renal injury, microalbumin and N-acetyl-beta-D-glucosaminidas (NAG), were measured in urine samples of study children (2016-2020). A total of 552 eligible children were studied, with a mean age of 4 years. We found that boys in the highest quartile of estimated melamine intake (≥0.68 μg/kg/day) had significantly higher urine ACR levels and in the highest quartile of estimated phthalate intake of DEHP (≥5.36 μg/kg/day), DEP (≥0.89 μg/kg/day), and DiBP (≥1.19 μg/kg/day) had significantly higher urine NAG levels when compared to the combined three lowest quartile ones as comparison groups. No significant associations were found between their mothers' phthalates and melamine intake during the third trimester and urine ACR and NAG in children. We conclude that children (particularly boys) with high co-exposure of melamine and certain phthalate chemicals among children have increased early markers of kidney injury.

PMID:40210160 | DOI:10.1016/j.envpol.2025.126206