Characterization of newfound natural luminescent properties of melamine, and development and validation of a method of high performance liquid chromatography with fluorescence detection for its determination in kitchen plastic ware

Finete, Virgínia de Lourdes Mendes; Gouvêa, Marcos Martins; Marques, Flávia Ferreira de Carvalho; Netto, Annibal Duarte Pereira

doi:10.1016/j.talanta.2014.02.012

Cited by 27 publications

(5 citation statements)

References 25 publications

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“…The reported band gap energies of g-C 3 N 4 range from 2.4 to 2.85 eV depending on different preparation conditions [ 31 , 32 , 33 , 34 , 35 ]. It is smaller than that of melamine [ 36 , 37 ]. The Raman spectra at different laser radiations ( Figure S1 ) shows that no graphite phase exists in the high-pressure-treated samples at temperatures below 700 °C.…”

Section: Resultsmentioning

confidence: 99%

Investigation on the Stability of Derivative Melam from Melamine Pyrolysis under High Pressure

Yuan

Luo

et al. 2018

Nanomaterials

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Although various kinds of carbon nitride precursors have been proposed, s-triazine-based structures are hardly reported because of their unfavorable energy, higher than that of heptazine-based ones. In this study, we investigate the thermal stability of s-triazine-based melam processed at a high pressure of 5 GPa and a temperature of 400–700 °C and complete the analyses of the composition and structure of the treated samples through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and elemental analyses (EA). Results show that melam can stably exist up to 600 °C at 5 GPa. XRD and FTIR analyses reveal that residual melamine can be pyrolyzed into melam as temperature increases from 400 °C to 600 °C at a high pressure, suggesting that melam may be purified through high-pressure pyrolysis. Further melam polymerization at a higher pressure is a promising strategy for the preparation of s-triazine-based carbon nitride precursors used for bulk carbon nitride synthesis.

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Section: Resultsmentioning

confidence: 99%

Investigation on the Stability of Derivative Melam from Melamine Pyrolysis under High Pressure

Yuan

Luo

et al. 2018

Nanomaterials

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“…Microwave‐assisted extraction, ultrasound‐assisted extraction, and accelerated solvent extraction are common field‐assisted extraction techniques. They have been adopted to analyze fluorescent whitening agents migrating from plastic beverage cups [63], screen migrating substances from baby Bibs [64], and analyze melamine in kitchen plastic ware [65].…”

Section: Sample Pretreatment Methods For Migrating Substances From Fomentioning

confidence: 99%

Research progress on sample pretreatment methods for migrating substances from food contact materials

Ouyang

et al. 2021

J of Separation Science

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Excessive absorption of migrating substances from food contact materials can affect human health. Thus, it is essential to analyze the migration of contaminant from food contact materials. However, comprehensive analysis has been challenged by low concentration of migrating substances, manifold and complex matrix interference of food contact materials. Therefore, appropriate sample pretreatment methods should be applied before instrumental detection, which is essential to improve the analytical efficiency, sensitivity, and reliability. This paper systematically reviews the development of sample pretreatment methods for analysis of migrating substances from food contact materials in the past decade. To extract volatile and semi‐volatile substances, headspace extraction, headspace solid phase microextraction, and purge and trap technique are discussed. For non‐volatile substances, solid–liquid extraction and field‐assisted extraction are usually used to extract them from food contact materials, while liquid–liquid extraction, solid phase extraction, and their corresponding microextraction techniques play important roles on enrichment process. In addition, new progress in developments of sample pretreatment methods of food contact materials is summarized, covering new devices, specific adsorbents, and sample preparation methods for rapid detection. An outlook of future prospect of sample pretreatment, especially for non‐targeted analysis of non‐intentionally added substances is briefly discussed.

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“…Melamine-formaldehyde resins are widely used in a variety of plastic products, such as kitchenware, as well as coating. Neutral melamine, e.g., melamine in water, is colorless and absorbs ultraviolet light , and fluoresces only ultraviolet light. , It is therefore a perfect host that is transparent in the visible range.…”

Section: Introductionmentioning

confidence: 99%

“…Neutral melamine, e.g., melamine in water, is colorless and absorbs ultraviolet light 15 , 16 and fluoresces only ultraviolet light. 17 , 18 It is therefore a perfect host that is transparent in the visible range.…”

Section: Introductionmentioning

confidence: 99%

Highly Luminescent TCNQ in Melamine

Mishra,

Mantel,

Kapusta

et al. 2024

ACS Appl. Opt. Mater.

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Optical properties of molecules change drastically as a result of interactions with surrounding environments as observed in solutions, clusters, and aggregates. Here, we make 7,7,8,8-tetracyanoquinodimethane (TCNQ) highly luminescent by encapsulating it in crystalline melamine. Colored single crystals are synthesized by slow evaporation of aqueous tetrahydrofuran solutions of melamine and TCNQ. Single-crystal X-ray diffraction reveals the lattice structure of pure melamine, meaning that the color is of impurities. Both mass spectrometry and UV−vis spectroscopy combined with density-functional theory calculations elucidate that the impurity species are neutral TCNQ and its oxidation product, dicyano-p-toluoyl cyanide anion (DCTC − ), whose concentrations in a melamine crystal can be controlled by adjusting the molar ratio between melamine and TCNQ in the precursor solution. Fluorescence excitation− emission wavelength mappings on the precursor solutions illustrate dominant emissions from DCTC − while the emission from TCNQ is quenched by the resonance energy transfer to DCTC − . On the contrary, TCNQ in crystalline melamine is a bright fluorophore whose emission wavelength centered at 450 nm with internal quantum yields as high as 19% and slow fluorescence lifetimes of about 2 ns. The method of encapsulating molecules into transparent melamine would make many other molecules fluorescent in solids.

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Characterization of newfound natural luminescent properties of melamine, and development and validation of a method of high performance liquid chromatography with fluorescence detection for its determination in kitchen plastic ware

Cited by 27 publications

References 25 publications

Investigation on the Stability of Derivative Melam from Melamine Pyrolysis under High Pressure

Investigation on the Stability of Derivative Melam from Melamine Pyrolysis under High Pressure

Research progress on sample pretreatment methods for migrating substances from food contact materials

Highly Luminescent TCNQ in Melamine

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