Infrared Spectroscopy Research Articles

Impact of UV Light Exposure During Printing on Thermomechanical Properties of 3D-Printed Polyurethane-Based Orthodontic Aligners

Aim: Polyurethane-based aligners, created through photoinitiated free-radical polymerization, have been the subject of numerous studies focusing solely on their mechanical properties. In contrast, we investigate their thermomechanical properties, which are crucial for their efficacy. This paper aims to investigate the effects of different UV light exposure durations on the complex modulus of elasticity, tan delta, glass transition temperature, and the degree of conversion (DC). Methods: Aligners were printed using Tera Harz TC-85 and NextDent Ortho Flex resin with specific exposure times (2, 2.4, 3, 4, and 4.5 s for Tera Harz; 5, 6, 7, and 8 s for NextDent) and processed per manufacturer guidelines. The degree of conversion was analyzed using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy, while Dynamic Mechanical Analysis (DMA) characterized the mechanical properties (complex modulus and tan delta) and the glass transition. Results: Tera Harz TC-85 showed a higher degree of conversion (90.29–94.54%), suggesting fewer residual monomers, which is potentially healthier for patients. However, its lower glass transition temperature (35.60–38.74 °C) might cause it to become rubbery in the mouth. NextDent Orto Flex, with a higher storage modulus (641.85–794.55 MPa) and Tg (49.36–50.98 °C), offers greater rigidity and stability at higher temperatures (greater than temperature in the oral cavity), ideal for orthodontic forces, though its lower degree of conversion raises health concerns. Conclusions: Tera Harz TC 85 generally achieves higher DC and more stable polymerization across different UV exposure times than NextDent Orto Flex. Optimal polymerization times significantly impact both the mechanical and thermal properties of these dental resins, with NextDent showing optimal properties at 7 s and Tera Harz benefiting from both very short and extended exposure times.

Insights into the phase behavior at interfaces using vibrational sum frequency generation spectroscopy.

Phase separation is ubiquitous at the interface between two distinct phases. Physical transformation during phase separation often plays a crucial role in many important mechanisms, such as lipid phase separation, which is fundamental for transport through biological membranes. Phase separation can be complex, involving changes in the physical state and the reorganization of molecular structures, influencing the behavior and function of materials and biological systems. Surface-sensitive vibrational sum frequency generation (VSFG) spectroscopy provides a powerful tool for investigating these interfacial processes. As a non-linear optical technique, VSFG spectroscopy is sensitive to changes in molecular orientation and interactions at interfaces, making it an ideal method for studying phase separation processes. Here, we review the molecular interaction mechanisms underlying phase separation. We also explore the application of VSFG spectroscopy in studying phase separation processes at different interfaces. In particular, we focus on oil-water interfaces, which are relevant in environmental and industrial contexts; polymer and lipid surfaces, important for materials science and biological membranes; and intrinsically disordered protein systems, which play key roles in cellular function and disease.

Coordination Networks from [Te4]2+ Clusters and Polynitriles

AbstractThe reactions of a series of organic polynitriles with [Te4][AsF6]2 in liquid SO2 solution lead either to reduction of [Te4]2+ to elemental tellurium or to the formation of coordination polymers. With 1,3‐dicyanobenzene (1,3‐DCB), 1,4‐dicyanobenzene (1,4‐DCB), 1,2,4,5‐tetracyanobenzene (TCB), tetracyanoethylene (TCNE) and tetracyanochinodimethane (TCNQ) the coordination complexes [Te4][AsF6]2 ⋅ 2(1,3‐DCB), [Te4][AsF6]2 ⋅ 3(1,4‐DCB) ⋅ 2SO2, [Te4][AsF6]2 ⋅ TCB, [Te4][AsF6]2 ⋅ TCNE and [Te4][AsF6]2 ⋅ TCNQ ⋅ 8 SO2 were isolated and characterized by crystal structure analyses and vibrational Raman spectroscopy. The nitriles are coordinated to the square‐planar clusters forming 1D chains, 2D arrangements and 3D networks. Tetrakis(dicyanomethylene)cyclobutendiide [C4(C{CN}2)4]2− is oxidized by [Te4]2+ to the neutral cyanocarbon C4(C{CN}2)4, structurally representing a 4[radialene]. The ionization potentials and electron affinities of the cyanamide anion, cyanogen, 1,2‐DCB, 1,3‐DCB, 1,4‐DCB, TCB, C4(C{CN}2)4, TCNE and TCNQ and those polynitriles, which cause reduction of [Te4]2+, were calculated at coupled‐cluster level of theory in order to examine possible reasons for the stability of the coordination polymers based on electronic properties of the nitriles.

In-Vitro Evaluation of Antioxidant Activity of Phaleria macrocarpa using Different Extraction Process and Determination of Functional Groups in the Extract by FTIR (Fourier Transform Infrared Spectroscopy)

In-Vitro Evaluation of Antioxidant Activity of Phaleria macrocarpa using Different Extraction Process and Determination of Functional Groups in the Extract by FTIR (Fourier Transform Infrared Spectroscopy)

Distinction of the Microcrystalline Celluloses from Eurycoma longifolia and Mannihot esculenta by Two-dimensional Correlation and Second Derivative IR Spectroscopy

Distinction of the Microcrystalline Celluloses from Eurycoma longifolia and Mannihot esculenta by Two-dimensional Correlation and Second Derivative IR Spectroscopy

Robust Computation and Analysis of Vibrational Spectra of Layered Framework Materials Including Host-Guest Interactions.

Layered framework materials, a rapidly advancing class of porous materials, are composed of molecular components stitched together via covalent bonds and are usually synthesized through wet-chemical methods. Computational infrared (IR) and Raman spectra are among the most important characterization tools for this material class. Besides the a priori known spectra of the molecular building blocks and the solvent, they allow for in situ monitoring of the framework formation during synthesis. Therefore, they need to capture the additional peaks from host-guest interactions and the bands from emerging bonds between the molecular building blocks, verifying the successful synthesis of the desired material. In this work, we propose a robust computational framework based on ab initio molecular dynamics (AIMD), where we compute IR and Raman spectra from the time-correlation functions of dipole moments and polarizability tensors, respectively. As a case study, we apply our methodology to a covalent organic framework (COF) material, COF-1, and present its AIMD-computed IR and Raman spectra with and without 1,4-dioxane solvent molecules in its pores. To determine robust settings, we meticulously validate our model and explore how stacking disorder and different methods for computing dipole moments and polarizabilities affect IR and Raman intensities. Using our robust computational protocol, we achieve excellent agreement with experimental data. Furthermore, we illustrate how the computed spectra can be dissected into individual contributions from the solvent molecules, the molecular building blocks of COF-1, and the bonds connecting them.

Characterization of Novel Exopolysaccharides from Weissella cibaria and Lactococcus lactis Strains and Their Potential Application as Bio-Hydrocolloid Agents in Emulsion Stability

The aim of the present study was the isolation of high exopolysaccharide (EPS) producers, Lactic Acid Bacteria (LAB) strains, from three types of milk: goat, sheep, and camel milk. Among 112 LAB isolates tested for their ability to produce EPS on MRS-sucrose agar, only 11 strains were able to produce EPS and only three higher producers’ strains were identified by 16S rRNA gene sequencing as two strains of Lactococcus lactis subsp. lactis (SP255, SP257) isolated from camel milk and one strain of Weissella cibaria (SP213) isolated from goat milk. The physicochemical characterization of the purified EPSs revealed a significant sugar yield, with concentrations ranging from 2.17 to 2.77 g/L, while the protein content remained relatively low (0.03 g/L). The UV-visible spectrum showed high Ultra Violet (UV) absorption at 240–280 nm and the Fourier-Transform Infrared (FTIR) spectra showed the presence of a large number of functional groups, including hydroxyl (-OH), carbonyl (-C=O), and methyl groups (-CH3). The EPS solubility indicated their hydrophilic properties and the investigation of interfacial properties indicated that these EPSs could be used as natural emulsifiers and stabilizers in both acidic and neutral emulsions. Moreover, a new type of emulsion system was developed by the utilization of EPSs in the formation of multilayer interfaces in oil-in-water (O/W) emulsions stabilized by sodium caseinate (CAS). Thus, the impact of an EPS addition on the particle size distribution and electrical charge has been studied. At pH 3, the studied EPSs adhered to the surfaces of caseinate-coated droplets and the stability of O/W emulsions was improved by adding certain concentrations of EPSs. The minimum concentration required to stabilize multilayer emulsions for EPSs SP255, EPS SP257, and EPS SP213 was 1.5, 1.5, and 1.7 g/L, respectively. These findings reveal a new EPS with significant potential for industrial use, particularly as an emulsion stabilizer.

The Crystal Chemistry of Boussingaultite, (NH4)2Mg(SO4)2·6H2O, and Its Derivatives in a Wide Temperature Range

The crystal structure, thermal behavior, and vibrational spectra of the anthropogenic analogue of boussingaultite, (NH4)2Mg(SO4)2·6H2O, and its dehydrated counterpart efremovite, (NH4)2Mg2(SO4)3, were studied in detail. The sample from the Chelyabinsk burning coal dumps has the composition of (NH4)1.92(Mg1.02Mn0.01Fe0.01)∑1.04(SO4)2·6H2O and crystallizes in the space group P21/a, with a = 9.3183(4), b = 12.6070(4), c = 6.2054(3) Å, β = 107.115(5)°, V = 696.70(5) Å3 (at 20 °C), Z = 2. The thermal evolution steps are as follows: boussingaultite (NH4)2Mg(SO4)2·6H2O (25–90 °C) → X-ray amorphous phase (100–150 °C) → efremovite (NH4)2Mg2(SO4)3 (160–340 °C) → MgSO4 Cmcm + Pbnm (340–580 °C) → MgSO4 Pbnm (580–700 °C). Thermal expansion is anisotropic, with the coefficients (×106 °C−1) α11 = 52(2), α22 = 68(2), α33 = –89(3), and αv = 31(3) at T = –123 °C; and α11 = 53(2), α22 = 67(2), α33 = 15(1), and αv = 136(3) at T = 60 °C. The maximal thermal expansion is along the b-axis and is due to straightening of corrugated pseudolayers (within the ab plane) of Mg(H2O)6 octahedra and SO4 tetrahedra with NH4 groups in the interlayer space. Vibrational spectroscopy outlines the general trend of dehydration and deammonization as the difference in the temperature intervals of these transformation steps allows separation of O–H and N–H vibrations in the process of dehydration by infrared and Raman spectroscopy. The intermediate partially dehydrated modification of boussingaultite was detected by in situ Raman spectroscopy at 110 °C that may correspond to ammonium leonite.

UiO-67 MOF-Encapsulated NHC-Based Single-Site Copper Catalyst and Its Application in Regioselective Borylation of Terminal Alkynes.

N-Heterocyclic carbenes (NHCs) act as versatile ligand backbones due to their strong σ-donation and π-acceptance properties. However, the encapsulation of NHC-coinage metal complexes in a metal-organic framework (MOF) to utilize them in organic catalysis is rare. In this work, an NHC-coordinated CuBr (NHC = Bn2Im; 1,3-dibenzyl-imidazol-2-ylidene) complex was encapsulated in UiO-67 MOF ((Bn2Im)2CuBr@UiO-67) and further utilized toward the regioselective protoboration of terminal alkynes. (Bn2Im)2CuBr@UiO-67 was found to show superior catalytic performance in aiding the protoboration of terminal alkynes, with a very high turnover frequency (TOF) of 14333.3 h-1, much higher than those of many other reported copper-based heterogeneous catalysts. Our catalyst also retained excellent catalytic efficiency for up to five cycles for the above-mentioned process. The newly synthesized (Bn2Im)2CuBr@UiO-67 and the recovered catalyst post-catalysis were characterized using various analytical techniques, including powder X-ray diffraction (PXRD), IR spectroscopy, field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS).

Energetic Salts of Cubane-1,4-Dimethylnitrocarbamate.

Several salts of cubane-1,4-dimethylnitrocarbamate (CMNC) were synthesized. The divalent CMNC is deprotonated by alkaline, alkaline earth metal, and nonmetal bases to form the corresponding salts. The compounds were characterized and analyzed by multinuclear NMR and IR spectroscopy, mass spectrometry, elemental analysis, single crystal X-ray, and thermoanalytical techniques. The energies of formation for the salts were calculated using Gaussian. Detonation performances were calculated with the Explo5 (V6.03) computer code. The sensitivities toward impact and friction were determined and compared to the neutral CMNC.

Thiazolidin-4-one derivatives as antitumor agents against (Caco-2) cell line: synthesis, characterization, in silico and in vitro studies

Compounds based on thiazolidinones have drawn particular attention in the field of medicinal chemistry as potential sources of novel drug-like molecules. In this study thiazolidin-4-one derivatives (3–17) were prepared by refluxing a mixture of β-aroylacrylic acid (1) and aryl thiosemicarbazone (2) and characterized using IR and 1H NMR spectroscopy. In silico, physicochemical descriptors and pharmacokinetic properties were assessed using the SwissADME web tool. Moreover, docking studies of synthesized compounds were performed in order to explore their binding to cyclooxygenase-2 (COX-2) (PDB code: 5IKT) and p53 (PDB code: 6MXZ). Some synthesized compounds were evaluated for their in vitro cytotoxic activity against colon cancer (Caco-2) cell line. Among the tested compounds, compound (16) showed a higher effect with (IC50 of 70 µg/ml). The synthesized compounds revealed reduced Caspase-3 and p53 gene expression, suggesting the potential antineoplastic effects of these compounds.

Strong spherical V2O5/TiO2–SiO2 composites obtained by template combined with sol-gel method

This study is devoted to the preparation of strong spherical composites V2O5/TiO2–SiO2 by a combined template and sol-gel method. The composition, size and shape of the colloidal particles in butanol ash with tetrabutoxytitanium and tetraethoxysilane, as well as the physicochemical processes leading to the strengthening of the spherical agglomerates obtained using an anion exchanger with a gel structure, have been determined. Electrophoresis, small-angle X-ray scattering, and viscometry were used to demonstrate the presence in the sol of positively charged colloidal particles of lenticular and cylindrical shape, whose size, when the sol is stabilised, reaches 53 Å. The absorption of the sol by the anion exchanger in vanadium form is due to the equalisation of the osmotic pressure in the anion exchanger/sol system. Spherical composites with a diameter of 300 µm were obtained. It was shown by X-ray diffraction that the composites consist of V2O5 with an orthorhombic structure, TiO2 with an anatase structure, and amorphous silicon dioxide. The interaction at the interface between the phases of V2O5 with TiO2 and SiO2, which leads to the strengthening of the sphere of the V2O5/TiO2–SiO2 composite, has been demonstrated by IR and Raman spectroscopy. The results obtained can be used for the synthesis of MxOy/TiO2–SiO2 oxide composites with spherical agglomerates.

Analyzing TVB-N in snakehead by Bayesian-optimized 1D-CNN using molecular vibrational spectroscopic techniques: Near-infrared and Raman spectroscopy

Total volatile basic nitrogen (TVB-N) is one of the key indicators for assessing fish freshness. This research employed near-infrared (NIR) and Raman spectroscopy methods to detect the TVB-N content in snakehead fillets. We extracted feature variables associated with TVB-N from NIR and Raman spectroscopy using Variable Crossover Point Arithmetic - Improved Reduced-Input Vector (VCPA-IRIV). Using these features, we established partial least squares (PLS) and One-dimensional Convolutional Neural Network (1D-CNN) models. Subsequently, data fusion strategies were employed to predict the TVB-N content. Notably, feature-level fusion in conjunction with Bayesian-optimized 1D-CNN, reached the best results, as evidenced by calibration and predictive correlation coefficients of 0.9677 and 0.9676 for TVB-N. These findings underscore the effectiveness of both NIR and Raman spectroscopy in evaluating fish freshness. The fusion of these two vibrational spectroscopy techniques enables a more rapid, efficient and comprehensive quantification of fish freshness.

Association between blood microplastic levels and severity of extracranial artery stenosis

Microplastics (MPs) contamination raises concerns about their impact on human health, particularly cardiovascular diseases. This study investigated the blood MPs levels in patients with extracranial artery stenosis (ECAS) and their possible link to disease severity. 20 ECAS and 10 control patients were recruited. Blood samples, collected before the digital subtract angiography (DSA) procedure, were analyzed by pyrolysis–gas chromatography mass spectrometry (Py-GC/MS), laser direct infrared (LDIR) spectroscopy, and scanning electron microscopy (SEM). Demographic and clinical information was also examined. Strict quality controls were implemented to prevent contamination. MPs were detected by Py-GC/MS in all blood samples, with concentrations significantly higher in ECAS group compared to control (174.89 ± 24.95 vs 79.82 ± 31.73 μg/g, p < 0.001), and polyvinyl chloride (PVC) and polyamide 66 (PA66) were the most abundant among the detected polymers. Further analyses suggested that higher concentrations of MPs may be associated with more severe artery stenosis (p < 0.001). Compared with the normal group, ECAS group had a higher level of D-dimer (0.61 ± 0.6 μg/L vs 0.28 ± 0.09 μg/L, p < 0.05) and longer Thrombin Time (sec) (18.30 ± 3.43 μg/L vs 16.25 ± 1.74 μg/L, p < 0.05). Additionally, LDIR and SEM detected the shape and physical properties of the MPs. In this study, we revealed significant higher blood MPs levels in ECAS patients, with a notable correlation between MPs concentrations and arterial stenosis severity.

Characterization of Atlantic Forest Tucum (Bactris setosa Mart.) Leaf Fibers: Aspects of Innovation, Waste Valorization and Sustainability.

This study investigates the fibers of tucum (Bactris setosa Mart.), a palm species native to the Atlantic Forest. The fibers manually extracted from tucum leaves were characterized to determine important properties that help with the recognition of the material. The fibers were also subjected to pre-bleaching to evaluate their dyeing potential. The extraction and characterization of these fibers revealed excellent properties, making this material suitable not only for manufacturing high-quality textile products but also for various technical and engineering applications. The characterization techniques included SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared Spectroscopy), TGA (Thermogravimetric Analysis), and tensile strength tests. These analyses showed that tucum fibers possess desirable properties, such as high tensile strength, with values comparable to linen but with a much finer diameter. The fibers also demonstrated good affinity for dyes, comparable to cotton fibers. An SEM analysis revealed a rough surface, with superficial phytoliths contributing to their excellent mechanical strength. FTIR presented a spectrum compatible with cellulose, confirming its main composition and highly hydrophilic nature. The dyeing tests indicated that tucum fibers can be successfully dyed with industrial direct dyes, showing good color yield and uniformity. This study highlights the potential of tucum fibers as a renewable, biodegradable, and sustainable alternative for the transformation industry, promoting waste valorization.

A 36-nucleus silver-thiolate cluster encapsulating double sulfates and co-protected by cyclen

New type of cyclic multi-dentate ligand named, Cyclen (1,4,7,10-tetraazacyclododecane, [12]aneN4), was successfully introduced onto the surface of a 36-nucleus double sulfates templated silver-thiolate cluster [(SO4)2@Ag36(SPhtBu)24(cyclen)4(CF3CO2)6(OH)2] (1). The nanocluster was investigated and characterized by single-crystal X-ray crystallography (SXRD), infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), thermogravimetry (TG), ultraviolet−visible (UV) spectroscopy, and photoluminescence (PL). The cluster shows very good solution stability in four different solvents and excellent thermal stability in the solid-state. It shows orange-red emission in EtOAc/THF/CH2Cl2/CHCl3 at 77 K. The lifetime of 1 in four different solvents is over 140 μs, and the highest quantum yield of 1 is 25.46 %. The nanocluster shows temperature-dependent photoluminescence properties in different solvents, which make them potential candidates in the fields of optical devices for future applications.

Reversible Grafting in Surface Organometallic Chemistry with a Late Transition‐Metal Amidinate Precursor

Supported catalysts are central to industrial catalytic processes. While traditional synthesis methods often yield poorly defined materials, thus complicating structural elucidation, Surface Organometallic Chemistry (SOMC) offers a solution, producing well‐defined structures. Recent advances in SOMC precursor development have shown that amidinate‐based precursors are a privileged class of precursors to generate supported metallic nanoparticles. In that context, this study investigates the grafting mechanism of a prototypical amidinate precursor, Ir(COD)(DIA) (1‐Ir), onto SiO2. Unique to amidinate complexes, grafting is shown to occur without ligand release, creating a reversible covalent bond. Using Ir‐TBOS as a molecular analogue, the structure of the grafted species and the reversibility of the reaction with O‐H groups are demonstrated using IR spectroscopy, single X‐Ray diffraction, variable‐temperature NMR spectroscopy, X‐Ray absorption spectroscopy (XAS), and supported by DFT calculations. Notably, we show that a partial degrafting is also possible at elevated temperatures under vacuum

A Melt-Processable Metal Halide Perovskite Ferroelectric.

Molecular ferroelectrics have increasingly garnered significant attention in both fundamental scientific research and technological applications due to their ease of processing, lightweight nature, and mechanical flexibility. Among these, metal halide perovskite ferroelectrics (MHP FEs), a subset of molecule-based ferroelectrics, exhibit diverse functionalities owing to their distinctive structures, thus emerging as a focal point of molecular ferroelectrics research. However, thin films, the predominant application form for MHP FEs, primarily rely on spin-coating, which presents considerable limitations. The development of melt-processable MHP FEs has been sparse, largely due to the challenge of integrating ferroelectricity with meltability. In this context, we propose a rational strategy for the successful synthesis of a melt-processable MHP FE, (MBPA)2PbBr4 (MBPA = N-methyl bromopropylammonium), featuring a notably low congruent melting temperature and excellent molten stability. The reversibility of solid and liquid states was demonstrated by X-ray diffraction and Raman and IR spectrum. Scanning electron microscopy examinations show a better quality of the melt-processed thin films compared to spin-coated ones. This study marks the successful implementation of integrating ferroelectricity and melt-processability into melt-processable MHP FEs, paving the way for a novel approach in processing MHP FEs and facilitating their future applications.

Accumulation characteristics and source analysis of microplastics derived traffic of soil in the Tibetan Plateau

The development of transportation infrastructure can stimulate economic growth. However, the environmental and human health risks associated with the release of traffic-derived microplastics (MPs) into the ecosystem must also be considered. This study examined four types of soil samples collected from the Qinghai-Tibetan Plateau along the Gemang Highway. The abundance, size, morphology, and types of MPs were analyzed using laser direct infrared (LDIR) spectroscopy to gain a better understanding of their distribution and characteristics. The average abundance of MPs in the study area was 2,247.92 ± 2,053.82n/kg. It showed the characteristics of wasteland (4,726.67 ± 2956.76n/kg) > wolfberry plantation (3,294.44 ± 2,881.93n/kg) > sandy land (1,519.44 ± 282.65n/kg) > soil along the highway (1,144.44 ± 611.01n/kg). 67.25% of MPs had a particle size of less than 100 μm, posing greater environmental risks. The 6 factors identified by the PMF model suggested a variety of potential sources of MPs and highlighted their connections to the transportation sector. The ecological risk assessment of MPs demonstrated a significant degree of risk, with particular concern regarding more toxic plastics use. This study provides fundamental data for the source analysis and ecosystem risk assessment of MPs derived traffic.

Rapid Classification of Milk Using a Cost-Effective Near Infrared Spectroscopy Device and Variable Cluster-Support Vector Machine (VC-SVM) Hybrid Models.

Removing fat from whole milk and adding water to milk to increase its volume are among the most common food fraud practices that alter the characteristics of milk. Usually, deviations from the expected fat content can indicate adulteration. Infrared spectroscopy is a commonly used technique for distinguishing pure milk from adulterated milk, even when it comes from different animal species. More recently, portable spectrometers have enabled in situ analysis with analytical performance comparable to that of benchtop instruments. Partial Least Square (PLS) analysis is the most popular tool for developing calibration models, although the increasing availability of portable near infrared spectroscopy (NIRS) has led to the use of alternative supervised techniques, including support vector machine (SVM). The aim of this study was to develop and implement a method based on the combination of a compact and low-cost Fourier Transform near infrared (FT-NIR) spectrometer and variable cluster-support vector machine (VC-SVM) hybrid model for the rapid classification of milk in accordance with EU Regulation EC No. 1308/2013 without any pre-treatment. The results obtained from the external validation of the VC-SVM hybrid model showed a perfect classification capacity (100% sensitivity, 100% specificity, MCC = 1) for the radial basis function (RBF) kernel when used to classify whole vs. not-whole and skimmed vs. not-skimmed milk samples. A strong classification capacity (94.4% sensitivity, 100% specificity, MCC = 0.95) was also achieved in discriminating semi-skimmed vs. not-semi-skimmed milk samples. This approach provides the dairy industry with a practical, simple and efficient solution to quickly identify skimmed, semi-skimmed and whole milk and detect potential fraud.