Melamine Powder Research Articles

Rapid detection and quantification of melamine, urea, sucrose, water, and milk powder adulteration in pasteurized milk using Fourier transform infrared (FTIR) spectroscopy coupled with modern statistical machine learning algorithms

There is an evident requirement for a rapid, efficient, and simple method to screen the authenticity of milk products in the market. Fourier transform infrared (FTIR) spectroscopy stands out as a promising solution. This work employed FTIR spectroscopy and modern statistical machine learning algorithms for the identification and quantification of pasteurized milk adulteration. Comparative results demonstrate modern statistical machine learning algorithms will improve the ability of FTIR spectroscopy to predict milk adulteration compared to partial least square (PLS). To discern the types of substances utilized in milk adulteration, a top-performing multiclassification model was established using multi-layer perceptron (MLP) algorithm, delivering an impressive prediction accuracy of 97.4 %. For quantification purposes, bayesian regularized neural networks (BRNN) provided the best results for the determination of both melamine, urea and milk powder adulteration, while extreme gradient boosting (XGB) and projection pursuit regression (PPR) gave better results in predicting sucrose and water adulteration levels, respectively. The regression models provided suitable predictive accuracy with the ratio of performance to deviation (RPD) values higher than 3. The proposed methodology proved to be a cost-effective and fast tool for screening the authenticity of pasteurized milk in the market.

Preparation of stable polyvinyl alcohol/polyurea hydrogel using oligomeric compounds containing urea-bonded

The aim of this research is the production of a biocompatible hydrogel film with high stability; the polymer should absorb enough water, and its structure should be preserved in water for a long time and not disintegrate. Polyvinyl alcohol (PVA) was chosen as the main polymeric base of the desired hydrogel. Oligomeric compounds with urea bonded containing active groups at two chain ends can react with the hydroxyl groups of the polymer and play the role of a cross-linker. Urea linkage oligomers (ULO) were prepared by reacting 2 mol of sulfamic acid, 3 mol of phosphorus, and 8 mol of urea in a molten state. The amount of PVA was kept constant, while the amount of ULO was different, the prepolymer solution was mold-dried at ambient temperature and subjected to a heat press. The gel behavior and characterization of the polymer films were investigated by FT-IR, NMR, SEM, ion chromatography, and XRD analyses, the data on the tensile strength and antibacterial properties of the samples are also reported. The production of a hybrid composite consisting of PVA and polyurea under the heat press has been confirmed; the ammonium phosphate, sulfate, nitrate, and melamine powder were produced in the layer of polymer structure. This innovative hybrid polymer with a network of urea bonds can be a favorable option for skin treatment applications due to the specific characteristic of urea known as keratolytic.

Efficiency Improvement of Photoelectrochemical Solar Cell Applications by Using Ternary Hybrid MoS2/g-C3N4/Cu2O

In this paper, molybdenum disulfide MoS2 was hybridized with graphene carbon nitrite (g-C3N4) and Cu2O in order to enhance the photoelectrochemical (PEC) activity and increase the light absorption range of Cu2O thin film. The melamine powder was poured in an empty container and then heated in a furnace to attain the powder. The ternary hetero-epitaxial growth was achieved by growing of MoS2/g-C3N4 on the Cu2O hybrid by a partial thermal oxidation process. The characteristics of MoS2/g-C3N4/Cu2O hybrid film were investigated through XRD, FT-IR and photoelectronchemistry-related measurements. The PEC behavior of the ternary hybrid electrode was investigated using current-voltage test under illumination. The efficiency calculated from current-voltage test under illumination shows that the presence of graphene carbon nitrite and molybdenum disulphide within the film networks, despite its low content, could stimulate substantial improvement in maximum photoconversion efficiency from 0.036% to 0.33%. This improvement is attributable to the enhancement of the electron-transferring proficiency upon the insertion of g-C3N4 and, MoS2 as confirmed by X-Ray Diffraction Analysis (XRD). The PEC test results signify that the photoelectrochemical activity of the MoS2/g-C3N4/Cu2O ternary hybrid is much higher than that of subtrate. The mechanisms accountable for the enhanced PEC behavior of the MoS2/g-C3N4/Cu2O ternary hybrid are discussed in detail.Keywords: Cuprous Oxide, J-V Characteristic, Hetero-structure, Photoelectrochemical, Thermal Oxidation.

Photocatalytic activity and mechanism of PCN@GO/AgNPs heterojunction in Rhodamine B degradation

An essential factor affecting the photocatalytic efficiency of a catalyst is the efficient separation of photogenerated electrons and holes. In the present study, a novel heterojunction material, PCN@GO/AgNPs, was synthesized with the aim of improving the photocatalytic performance. This achievement was accomplished through the establishment of a heterojunction between graphitic phase carbon nitride (PCN) and nano silver (AgNO3). The PCN was prepared from melamine powder calcined at high temperature under nitrogen environment, and was modified by graphene oxide (GO) to form heterojunction with silver nanoparticles, which resulted in a significant improvement in the photocatalytic efficiency of the catalyst. Under ultraviolet（UV）excitation, the catalytic rate constant of PCN@GO/AgNPs heterojunction on RhB dye can reach 10.594 × 10−2 min−1. This research represents a promising strategy to increase the surface area of PCN photocatalysts through simply doping noble metal and thus improving photocatalytic performance, which contributes to understand the reaction mechanism of photocatalytic effect.

Plasma synthesis of K-doped amorphous carbon nitride with passivated trap states for enhanced photocatalytic H2O2 production

Amorphous carbon nitride (ACN) is a promising semiconductor photocatalyst for photocatalytic H2O2 production. However, its actual activity is hindered by a high recombination rate of photoexcited charge carriers. Herein we report a K-doped ACN (K-ACN) photocatalyst synthesized via Ar plasma treatment to the modified melamine and KCl powder mixture at a moderate temperature. The as-synthesized K-ACN exhibits significantly enhanced photocatalytic properties for H2O2 production with a yield of 6.21 mM h−1, which is 6 times higher than that of bulk CN. Moreover, the H2O2 yield can be further increased to 13.95 mM h−1 by adjusting the pH value. The significantly enhanced photocatalytic property is mainly attributed to the introduction of K+, which is conducive to tuning the electronic structure, extending π conjugated system, passivating trap states and enhancing photocatalytic activity. The result has provided a facile and effective strategy for the modification of ACN to significantly boost its photocatalytic activity.

All-in-One Process for Mass Production of Membrane-Type Carbon Aerogel Electrodes for Solid-State Rechargeable Zinc-Air Batteries.

This study presents a mass-production process for conductive carbon membrane-type sponge electrodes derived from recyclable cellulose biowaste. It includes an all-in-one hydrogel fabrication process for mass production, which significantly shortens the complex and expensive process for the conventional process of catalytic electrodes based on conductive supporting substrates such as the gas diffusion layer (GDL). The presence of pre-adsorbed melamine powder in the all-in-one hydrogel induces internal diffusion of the gaseous reactant for the uniform growth of carbon nanotubes (CNTs) onto the sponge-like porous carbon aerogel with a relatively thick and tortuous pore structure, thereby providing the electrochemical properties and mechanical strength simultaneously required for the air electrodes of rechargeable and quasi solid-state zinc-air batteries.

Co-Immobilization of Lactase and Glucose Isomerase on the Novel g-C3N4/CF Composite Carrier for Lactulose Production.

The g-C3N4/CF composite carrier was prepared by ultrasound-assisted maceration and high-temperature calcination. The enzyme immobilization using the g-C3N4/CF as the novel carrier to immobilize lactase and glucose isomerase was enhanced for lactulose production. The carbon fiber (CF) was mixed with melamine powder in the mass ratio of 1:8. The g-C3N4/CF composite carrier was obtained by calcination at 550 °C for 3 h. After the analysis of characteristics, the g-C3N4/CF was successfully composited with the carbon nitride and CF, displaying the improvement of co-immobilization efficiency with the positive effects on the stability of the enzyme. The immobilization efficiency of the co-immobilized enzyme was 37% by the novel carrier of g-C3N4/CF, with the enzyme activity of 13.89 U g-1 at 60 °C. The relative activities of co-immobilized enzymes maintained much more steadily at the wider pH and higher temperature than those of the free dual enzymes, respectively. In the multi-batches of lactulose production, the relative conversion rates in enzymes co-immobilized by the composite carrier were higher than that of the free enzymes during the first four batches, as well as maintaining about a 90% relative conversation rate after the sixth batch. This study provides a novel method for the application of g-C3N4/CF in the field of immobilizing enzymes for the production of lactulose.

Well-designed MXene-derived Carbon-doped TiO2 coupled porous g-C3N4 to enhance the degradation of ciprofloxacin hydrochloride under visible light irradiation

In this work, using melamine and MXene powder as precursors, NH4Cl as a template, a novel S-scheme heterojunction composite material g-C3N4/C-TiO2 was synthesized by a one-step calcination method. During the calcination process, the gas template NH4Cl played a dual role, which not only striped the massive g-C3N4 into porous flakes with a larger specific surface area but also striped the agglomerated MXene derivatives (C-TiO2) nanoparticles, making them bind more closely with g-C3N4. The charge separation efficiency and photocatalytic performance were greatly improved due to the formation of heterojunction and the larger specific surface area of the sample. Within 50 min, the g-C3N4/C-TiO2 exhibited high photocatalytic performance toward ciprofloxacin hydrochloride (CIP·HCl) with degradation efficiencies of 88.14% under visible light (λ ≥ 420 nm), which was 8.9 times higher than that of pure g-C3N4. In addition, we also used a series of characterizations to confirm the mechanism of S-scheme heterojunction and inferred the possible CIP photodegradation pathway.

Thermal stability of polymeric carbon nitride (PCN)-Al2O3–ZrO2 nanocomposites used in photocatalysis

Polymeric carbon nitride (PCN) was recently found to have extensive applications in the field of photocatalysis. Knowledge about thermal stability of PCN nanocomposites is crucial for this application and designing the final product. In this work, the thermal stability of PCN-Al2O3–ZrO2 nanocomposites was investigated. PCN nanocomposites were obtained in two steps: (1) microwave hydrothermal synthesis of co-precipitated AlOOH and ZrO2 precursors, followed by drying; (2) mixing the nanopowders with melamine powder and annealing in air in a tube furnace at 400, and 450 °C. The PCN nanocomposites were examined by attenuated total reflection technique of Fourier transformed infrared spectroscopy. Also, the evolved gas analysis was performed combining differential scanning calorimetry and thermogravimetry coupled with mass spectroscopy and FTIR. The results show that only PCN-Al2O3–ZrO2 nanocomposite obtained at 400 °C is stable from room temperature up to 490 °C and during thermal decomposition, in one step releases ammonia (NH3), cyanic acid (HNCO), water (H2O), and carbon dioxide (CO2). The limitation of the PCN-Al2O3–ZrO2 thermal stability and performance is AlOOH–ZrO2 used as a nanocomposite component.

One-pot pyrolysis method for synthesis of Fe/N co-doped biochar as an effective peroxymonosulfate activator for RhB degradation

BackgroundIt was an effective method and research focus to remove recalcitrant organic pollutants by advanced oxidation processes based on persulfate activation with composite material as heterogeneous catalysts. MethodsFe/N co-doped biochar (Fe/N-BC) was synthesized via one-pot calcination method with anhydrous FeCl3, melamine, and grape skin powder as precursors. Characterization results showed that biomass and melamine could anchor iron species on BC matrixes by coordination. Significant findingsThe Fe/N0.1-BC exhibited significant activities toward peroxymonosulfate (PMS) activation, and 20 mg/L RhB can be degraded completely in 10 min with 0.05 g/L of the material and 0.5 g/L PMS. Electron paramagnetic resonance (EPR) study and free radical quenching experiments indicated that singlet oxygen (1O2), sulfate radicals (SO4•−), and hydroxyl radicals (•OH) were the main reactive oxidizing species, and non-radical mechanism and free radical process were considered to be involved in the degradation of the pollutants. Control experiments revealed that the enhanced active sites were mainly ascribed to rich defects as well as the synergistic effect among Fe and N doping into carbon substrate. The Fe/N-BC owned the merits of environmentally friendly raw materials, easy synthesis, and high activation efficiency, exhibiting splendid prospect for environmental application.

Facile fabrication of cobalt/nitrogen-doped graphite composites with high-performance microwave absorption

Magnetic metals are vital microwave-absorbing materials in alleviating electromagnetic (EM) pollution; however, in practical applications they are limited by their high density and relatively narrow absorption band. An effective strategy for addressing this issue is compounding magnetic metals with carbon materials. In this work, we fabricated the carbon/nitrogen-doped graphite (Co/NC) composites using a simple and low-cost method by directly calcining a dry mixture of melamine and Co powders in Ar gas. Part of Co/NC composite was calcined at 800 °C (Co/NC−800). The effects of variations in phase composition and morphology on the EM parameters and microwave-absorbing performance were investigated. Compared to pure Co, Co/NC−800 composite exhibits excellent microwave-absorbing performance such as strong absorption, better EM wave attenuation, and a lighter weight. Particularly, Co/NC−800 composite achieved the minimum reflection loss (RL) of −57.76 dB at 4.88 GHz and an effective absorption bandwidth (EABW, RL ≤ −10 dB) of 14.26 GHz (3.74–18.00 GHz) at a coating thickness d of 1.00–5.00 mm. Further, the maximum EABW of 5.50 GHz was attained at d = 1.86 mm. The optimal impedance matching, multiple scattering and reflections of EM waves on rough surfaces, and strong dielectric loss including conduction loss, interfacial and dipolar polarizations were noted as the main factors for the enhanced EM energy absorbance of Co/NC−800 composite. We believe our work may serve as a guideline for the fabrication of other light carbon-based magnetic metal composites as EM wave absorbers.

The mechanical and thermal properties of graphitic carbon nitride (g‐C3N4)‐based epoxy composites

AbstractNumerous ways to reinforce epoxy resin and improve its thermomechanical properties have been attempted using organic and inorganic nanoparticles. In this paper, graphitic carbon nitride (g‐C3N4) nanoparticles were synthesized and used to improve the mechanical properties and thermal stability of epoxy composites. The g‐C3N4 was synthesized from cheap melamine powder using a simple one‐step thermal treatment, then was used to reinforce the resin at different weight percentages (wt%). X‐ray diffraction, scanning electron microscopy (SEM), and Fourier infrared spectroscopy were used to characterize the g‐C3N4 and ensure its successful synthesis by studying the changes in its crystal structure, morphology, and chemical structure. The filler was dispersed in the resin using a combination of ultrasonication and high shear mixing. The results showed that the mechanical properties were optimum when 0.5 wt% g‐C3N4 was used. The tensile strength and fracture toughness of the resulting epoxy composite improved by 21.8% and 77.3%, respectively. SEM was used to investigate the morphologies of cracks formed in epoxy composite specimens after the tensile testing. The SEM micrographs of the fracture surface showed a transition from a brittle to a rough morphology, signifying the enhancement in the composites' toughness. Thermogravimetric analysis showed a good improvement in degradation temperature of up to 8.86% while dynamic mechanical analysis showed that the incorporation of g‐C3N4 did not affect the material's glass transition temperature.

Evaluation of a novel C-Arm draping technique to minimize surgical field contamination and surgery time.

The purpose of this study is to compare the sterility of three C-Arm draping techniques: the clip-drape, sterile pouch, and a novel drape tower method. We hypothesize that our novel technique will minimize floor contamination from reaching the surgical field while allowing the C-Arm machine to rotate between lateral and anterior-posterior positions more quickly. Five trials consisting of rotating the C-Arm and simulating surgeon movement were run using each technique. Ultraviolet light illuminating melamine powder was used to represent floor contamination. Measurements of melamine powder encroachment on the drapes were taken using the top of the C-Arm in lateral position as the reference point. The time needed to assemble, deploy, and retract the C-Arm was measured for each technique. The gown, gloves, and mayo stand were also examined after each trial for contamination. Compared to the clip drape, the drape tower prevented contamination from reaching the C-Arm by an additional 30.5cm (95% confidence interval (CI): 17.0-43.9, P < 0.001). The drape tower had faster deployment and retraction times than both the clip drape (P < 0.001 and P < 0.001, respectively) and sterile pouch (P=0.011 and P < 0.001, respectively). The clip drape and sterile pouch exhibited glove contamination in two (40%) simulations, while the drape tower showed no instances of contamination (P=0.255). The novel drape tower technique limits the encroachment of floor contamination onto sterile drapes. It should be considered as an alternative draping method for lower extremity surgery.

Enhanced peroxymonosulfate decomposition into [rad]OH and 1O2 for sulfamethoxazole degradation over Se doped g-C3N4 due to induced exfoliation and N vacancies formation

The development of low-cost and facile synthesized metal-free peroxymonosulfate (PMS) activation catalysts is paramount important for the practical remediation of organic pollution caused by antibiotics. Graphitic carbon nitride (g-C3N4) as a promising alternative, to improve its PMS activation performance, we proposed an efficient method to prepare exfoliated Se doped g-C3N4 (Se-g-C3N4) with 0.095 wt% Se and more exposed reactive N vacancies through the thermal polycondensation of melamine and Se powder at 550 ℃. The results proved that 93.0% of sulfamethoxazole (SMX) can be degraded over Se-g-C3N4 with PMS in 180 min, and the corresponding degradation rate constant of 0.0149 min−1 was even 4-fold higher than that of bulk g-C3N4 (0.0039 min−1). It was found that more 1O2 was generated and OH was further identified because of the enhanced PMS self-decomposition process, especially PMS reduction via electron transfer from Se-g-C3N4. The introduction of Se atom in g-C3N4 structure not only induced the formation of nitrogen vacancies to modulate the electron distribution of g-C3N4, but also favored the exfoliation of inter-facial stacking to increase the exposure of active sites due to the large atomic radius of Se. Hence, this work offered a new strategy for improving the PMS activation performance of g-C3N4 by regulating its electron deficiency and exposing more reactive N vacancies simultaneously.

A novel approach to synthesize nitrogen-doped graphene in aspects of milling energy

Systematic report on the synthesis of Nitrogen-doped graphene (N-doped GNP) via solid-state ball milling of graphite with melamine powder is represented in the article. At the first time, the article briefs the mathematical representation for energy released at different speed of rotation of planetary ball mill using the various diameter of balls. It was observed that large diameter balls release more energy as compared to smaller balls. However, when combination of balls with different diameters were used, the energy released was much larger as compared with balls of individual diameter. Solid-state ball milling technique has successfully exfoliated the graphite into multilayer graphene and at the same time it has doped the nitrogen atoms onto the edge of graphene sheets. Field-emission scanning electron (FESEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and particle size analyzer has confirmed the quality and final particle size of as-prepared graphene nanosheets (GNP). The particle size of 48 h milled graphene is observed to be double to that of 72 h graphene sample.

Enhanced electrical conductivity of doped graphene fiber via vacuum deposition

Graphene fiber is considered as a potential material for wearable applications owing to its lightness, flexibility, and high electrical conductivity. After the graphene oxide (GO) solution in the liquid crystal state is assembled into GO fiber through wet spinning, the reduced graphene oxide (rGO) fiber is obtained through a reduction process. In order to further improve the electrical conductivity, herein, we report N, P, and S doped rGO fibers through a facile vacuum diffusion process. The precursors of heteroatoms such as melamine, red phosphorus, and sulfur powders were used through a vacuum diffusion process. The resulting N, P, and S doped rGO fibers with atomic% of 6.52, 4.43 and 2.06% achieved the higher electrical conductivities compared to that of rGO fiber while preserving the fibrious morphology. In particular, N doped rGO fiber achieved the highest conductivity of 1.11 × 104 S m−1, which is 2.44 times greater than that of pristine rGO fiber. The heteroatom doping of rGO fiber through a vacuum diffusion process is facile to improve the electrical conductivity while maintaining the original structure.

Laser synthesis of TiO2–carbon nanomaterial layers with enhanced photodegradation efficiency towards antibiotics and dyes

Graphene-based photocatalytic layers were prepared by reactive matrix assisted pulsed laser evaporation technique. Binary, nitrogen doped reduced graphene oxide (RGO)/TiO2 and ternary RGO/TiO2/graphitic carbon nitride (g-C3N4) compounds were synthesized and simultaneously deposited onto solid substrates. Aqueous dispersions of commercial graphene oxide platelets and TiO2 nanoparticles were prepared. NH3 or melamine powder was added to the dispersions to achieve enhanced nitrogen doping and synthesis of g-C3N4 during laser irradiation. The photocatalytic efficiency of the layers towards degradation of antibiotic, chloramphenicol and organic dye molecules was systematically investigated and correlated with structural, compositional, and morphological features. This study provides new insights into the importance of TiO2 crystal facets and the synergistic effects between TiO2 nanocrystals and the other constituents, nitrogen doped RGO and g-C3N4 of the hybrid layers. As a result of combined effect of constituent materials, TiO2, RGO, and g-C3N4 as well as N doping of RGO, through the generation of quaternary and pyrrolic N functionalities, the composite layers showed high photocatalytic efficiency for degradation of organic molecules. Stability and reusability experiments indicated that the composite layers maintain their high photodegradation efficiency towards organic molecules during consecutive degradation cycles. Active radical scavenging experiments were also carried out in order to determine the role of the main active species involved in the photocatalytic degradation process.

In situ synthesis of ultrafine TiO2 nanoparticles modified g-C3N4 heterojunction photocatalyst with enhanced photocatalytic activity

To improve the redox performance and light absorption property, the 2D/0D g-C3N4/TiO2 heterojunction photocatalyst were successfully fabricated by co-annealing process based on melamine powder and ultrafine TiO2 nanoparticles (about 9.87 nm) obtained from electrochemical etching technology. The surface micromorphology, crystal structure, basic element composition, chemical structure, specific surface and optical performance were analyzed by SEM-EDS, TEM, HR-TEM, XRD, XPS, FTIR and Ultraviolet–visible diffuse reflection spectra (UV–vis DRS). The photocatalytic performance of g-C3N4/TiO2 photocatalyst was assessed by the degradation of tetracycline hydrochloride (TC) under simulated sunlight irradiation. The results showed that the obtained TiO2 powder had extremely smaller particle size and higher photocatalytic activity than commercial P25. The coupling of 0D TiO2 nanoparticles and 2D g-C3N4 nanosheet further promoted the visible light absorption performance of TiO2. The unique g-C3N4/TiO2 heterojunction photocatalyst exhibited remarkable photocatalytic performance for the degradation of TC, whose degradation rate could reach to 99.40% under 120 min irradiation. The kinetic constant of the g-C3N4/TiO2 photocatalyst was 1.48 times of that of TiO2. The ESR results confirmed ·OH and ·O2– radicals produced in the photocatalytic process. This work could provide an effective reference for the fabrication of ultrafine TiO2 powder and binary heterojunction photocatalyst with excellent photocatalytic activity for organic pollutants degradation in water purification.

Surface modification of organic powders for enhanced rheology via atomic layer deposition

Some organic additive manufacturing feedstocks can be cohesive and tend to agglomerate in suspensions, which can lead to significant challenges in formulating solids-loaded fluids, like those used in many additive manufacturing processes. By depositing an ultra-thin, layer of a second material conformally with the surface of the feedstock powder, Atomic Layer Deposition (ALD) can be used to uniquely modify the surface and, thereby, cohesion of the powder material without changing the properties of the bulk material. This paper demonstrates low temperature (<115 °C), ALD of aluminum oxide on temperature-sensitive materials: first, on polyimide thin film flats, then, on melamine and nylon organic powder feedstocks with the goal of improving their powder rheology. The process produced amorphous aluminum oxide-hydroxide coatings that are both uniform and conformal to the powder’s surface. Aluminum oxide coatings on the nylon powders did not show a significant change in the flow properties of the powder, given the already low cohesivity of nylon. In contrast, the highly cohesive melamine powders exhibited significant improvements in flowability after being coated with a layer as thin as 20 nm, due to a reduction in inter-particle cohesivity. The basic flowability decreased from 199 to 185 mJ and the specific energy increased from 4.95 to 6.39 mJ/g.

Improving Sensitivity in Raman Imaging for Thin Layered and Powdered Food Analysis Utilizing a Reflection Mirror

Raman imaging has been proven to be a powerful analytical technique for the characterization and visualization of chemical components in a range of products, particularly in the food and pharmaceutical industries. The conventional backscattering Raman imaging technique for the spatial analysis of a deep layer suffers from the presence of intense fluorescent and Raman signals originating from the surface layer which mask the weaker subsurface signals. Here, we demonstrated the application of a new reflection amplifying method using a background mirror as a sample holder to increase the Raman signals from a deep layer. The approach is conceptually demonstrated on enhancing the Raman signals from the subsurface layer. Results show that when bilayer samples are scanned on a reflection mirror, the average signals increase 1.62 times for the intense band at 476 cm−1 of starch powder, and average increases of 2.04 times (for the band at 672 cm−1) for a subsurface layer of high Raman sensitive melamine powder under a 1 mm thick teflon sheet. The method was then applied successfully to detect noninvasively the presence of small polystyrene pieces buried under a 2 mm thick layer of food powder (a case of powdered food adulteration) which otherwise are inaccessible to conventional backscattering Raman imaging. In addition, the increase in the Raman signal to noise ratio when measuring samples on a mirror is an important feature in many applications where high-throughput imaging is of interest. This concept is also applicable in an analogous manner to other disciplines, such as pharmaceutical where the Raman signals from deeper zones are typically, substantially diluted due to the interference from the surface layer.