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Spectroscopic studies on the binding of bromocresol purple to different serum albumins and its bilirubin displacing action

Faizul FM, Abdul Kadir H, Tayyab S

J. Photochem. Photobiol. B, Biol., 2008 Jan 30;90(1):1-7.
PMID: 18024146

The interaction between bromocresol purple (BCP) and bovine serum albumin (BSA)/porcine serum albumin (PSA) was investigated both in the absence and presence of bilirubin (BR) using absorption/absorption difference spectroscopy. A significant red shift in the absorption maxima of BCP accompanied by a decrease in absorbance was indicative of BCP binding to albumin. The titration of BSA and PSA with BCP using absorption difference spectroscopy and analysis of results by Benesi-Hildebrand equation yielded the values of association constant, K as 9.9+/-0.9x10(4)Lmol(-1) and 4.1+/-0.3x10(4)Lmol(-1) for BSA and PSA, respectively. The differential extinction coefficient (Deltaepsilon) of 34,484M(-1)cm(-1) at 615nm and 41,870M(-1)cm(-1) at 619nm were estimated for BSA and PSA, respectively. Decrease in (DeltaAbs.)(615nm) of BCP-BSA complex with the increase in ionic strength suggested the role of hydrophobic interactions in the binding phenomenon. A significant blue shift in the absorption maxima and change in (DeltaAbs)(lambdamax) values of BR-albumin complexes upon addition of increasing concentrations of BCP revealed the BR displacing action of BCP on albumin molecule.

Matched MeSH terms: Spectrophotometry
Identification of naphthalene metabolism by white rot fungus Pleurotus eryngii

Hadibarata T, Teh ZC, Rubiyatno, Zubir MM, Khudhair AB, Yusoff AR, et al.

Bioprocess Biosyst Eng, 2013 Oct;36(10):1455-61.
PMID: 23334282 DOI: 10.1007/s00449-013-0884-8

The use of biomaterials or microorganisms in PAHs degradation had presented an eye-catching performance. Pleurotus eryngii is a white rot fungus, which is easily isolated from the decayed woods in the tropical rain forest, used to determine the capability to utilize naphthalene, a two-ring polycyclic aromatic hydrocarbon as source of carbon and energy. In the meantime, biotransformation of naphthalene to intermediates and other by-products during degradation was investigated in this study. Pleurotus eryngii had been incubated in liquid medium formulated with naphthalene for 14 days. The presence of metabolites of naphthalene suggests that Pleurotus eryngii begin the ring cleavage by dioxygenation on C1 and C4 position to give 1,4-naphthaquinone. 1,4-Naphthaquinone was further degraded to benzoic acid, where the proposed terepthalic acid is absent in the cultured extract. Further degradation of benzoic acid by Pleurotus eryngii shows the existence of catechol as a result of the combination of decarboxylation and hydroxylation process. Unfortunately, phthalic acid was not detected in this study. Several enzymes, including manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase and 2,3-dioxygenase are enzymes responsible for naphthalene degradation. Reduction of naphthalene and the presence of metabolites in liquid medium showed the ability of Pleurotus eryngii to utilize naphthalene as carbon source instead of a limited glucose amount.

Matched MeSH terms: Spectrophotometry, Ultraviolet
Fulltext Solubility enhancement of simvastatin by arginine: thermodynamics, solute-solvent interactions, and spectral analysis

Meor Mohd Affandi MM, Tripathy M, Shah SA, Majeed AB

Drug Des Devel Ther, 2016;10:959-69.
PMID: 27041998 DOI: 10.2147/DDDT.S94701

We examined the solubility of simvastatin in water in 0.01 mol·dm(-3), 0.02 mol·dm(-3), 0.04 mol·dm(-3), 0.09 mol·dm(-3), 0.18 mol·dm(-3), 0.36 mol·dm(-3), and 0.73 mol·dm(-3) arginine (ARG) solutions. The investigated drug is termed the solute, whereas ARG the cosolute. Phase solubility studies illustrated a higher extent of solubility enhancement for simvastatin. The aforementioned system was subjected to conductometric and volumetric measurements at temperatures (T) of 298.15 K, 303.15 K, 308.15 K, and 313.15 K to illustrate the thermodynamics involved and related solute-solvent interactions. The conductance values were used to evaluate the limiting molar conductance and association constants. Thermodynamic parameters (ΔG (0), ΔH (0), ΔS (0), and E s) for the association process of the solute in the aqueous solutions of ARG were calculated. Limiting partial molar volumes and expansibilities were evaluated from the density values. These values are discussed in terms of the solute-solvent and solute-cosolute interactions. Further, these systems were analyzed using ultraviolet-visible analysis, Fourier-transform infrared spectroscopy, and (13)C, (1)H, and two-dimensional nuclear overhauser effect spectroscopy nuclear magnetic resonance to complement thermophysical explanation.

Matched MeSH terms: Spectrophotometry, Ultraviolet
Fulltext Effects of heat, pH, antioxidant, agitation and light on betacyanin stability using red-fleshed dragon fruit (Hylocereus polyrhizus) juice and concentrate as models

Wong YM, Siow LF

J Food Sci Technol, 2015 May;52(5):3086-92.
PMID: 25892813 DOI: 10.1007/s13197-014-1362-2

Red-fleshed dragon fruit (Hylocereus polyrhizus) is rich in antioxidants. The aim of this study was to determine the effects of heat pasteurization, pH adjustment, ascorbic acid addition as well as storage under agitation and light or dark condition on betacyanin content in red-fleshed dragon fruit (Hylocereus polyrhizus) juice and concentrate. The concentrate was produced by concentrating clarified red-fleshed dragon fruit juice in a rotary evaporator at 40 °C. UV-Visible spectrophotometer was used for analyzing betacyanin content. Addition of 0.25 % ascorbic acid, pH 4.0, and pasteurization at 65 °C for 30 min were selected as the best processing conditions to retain betacyanin content in red-fleshed dragon fruit juice. Storage at the agitation speed of 220 rpm showed that the concentrated samples had higher betacyanin stability compared to juice, while both juice and concentrate had almost similar betacyanin stability when tested for storage in the presence of light. In summary, ascorbic acid stabilized betacyanin in both juice and concentrate at agitated or non-agitated conditions. In contrast, light degraded betacyanin in both juice and concentrate models.

Matched MeSH terms: Spectrophotometry
The study of dipole moment of some substituted acetic acids in an electronically excited state

Murthy MB, Daya Sagar BS, Patil RL

Spectrochim Acta A Mol Biomol Spectrosc, 2003 Apr;59(6):1277-80.
PMID: 12659896

The electronic absorption spectra of eight substituted acetic acids have been measured at room temperature in several solvents. The ground state dipole moments are evaluated experimentally for these molecules. These ground state values are used in conjunction with the spectral results to evaluate their first electronically excited state dipole moments. For all the molecules investigated here the dipole moments in the excited state are higher than their ground state values.

Matched MeSH terms: Spectrophotometry
Distribution of oil and grease and petroleum hydrocarbons in the Straits of Johor, peninsular Malaysia

Abdullah AR, Woon WC, Bakar RA

Bull Environ Contam Toxicol, 1996 Jul;57(1):155-62.
PMID: 8661474
Matched MeSH terms: Spectrophotometry, Ultraviolet
Determination of silver, bismuth, cadmium, copper, iron, nickel and zinc in lead- and tin-base solders and white-metal bearing alloys by atomic-absorption spectrophotometry

Chong C

Talanta, 1986 Jan;33(1):91-4.
PMID: 18964038

A simple atomic-absorption spectrophotometry method is described for the determination of silver, bismuth, cadmium, copper, iron, nickel and zinc in lead- and tin-base solders and white-metal bearing alloys, with use of a single sample solution. The sample is dissolved in a mixture of hydrobromic acid and bromine, then fumed with sulphuric acid. The lead sulphate is dissolved in concentrated hydrochloric acid. The method is particularly suitable for the determination of silver and bismuth, which are co-precipitated with lead sulphate. The other elements can also be determined after removal of the lead sulphate by filtration.

Matched MeSH terms: Spectrophotometry, Atomic
Fulltext Experimental and DFT data of p-chlorocalix[4]arene as drugs receptor

Kadir MA, Abdul Razak FI, Haris NSH

Data Brief, 2020 Oct;32:106263.
PMID: 32905010 DOI: 10.1016/j.dib.2020.106263

The data in this article provide information on spectroscopic and theoretical data for p-chlorocalix[4]arene when combined with selected drugs, such as paracetamol, ibuprofen, and cetirizine. The present spectroscopic data are generated from Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance (1H NMR and 13C NMR), and Ultraviolet-Visible spectroscopy (UV-Vis) as the key tools for molecular characterization. The measurement of the optimization energy, interaction energy, and the band gap energy between the molecules was calculated by Gaussian 09 software. It is interesting to note that of the three titled drugs identified, p-chlorocalix[4]arene showed the highest interaction energy with paracetamol, followed by ibuprofen and cetirizine.

Matched MeSH terms: Spectrophotometry, Ultraviolet
Fulltext Differentiation of ripe and unripe fruit flour using mineral composition data-Statistical assessment

Alkarkhi AFM, Alqaraghuli WAA, Mohamed Zam NR, Manan DMA, Mahmud MN, Huda N

Data Brief, 2020 Jun;30:105414.
PMID: 32258278 DOI: 10.1016/j.dib.2020.105414

Data on the mineral composition and content of one heavy metal measured in three different fruit flours prepared from ripe and unripe fruits (pulp and peel) are presented. The mineral composition (sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn)) and content of one heavy metal (lead (Pb)) of the flours were analyzed by atomic absorption spectrophotometry. The analysis showed that the data can be used for differentiation between different fruits and stages of ripeness, as revealed by discriminant analysis and cluster analysis. The data provided can be used by researchers and scientists in the differentiation of fruits based on major and minor mineral elements.

Matched MeSH terms: Spectrophotometry, Atomic
Enantioseparation of ketoconazole and miconazole by capillary electrophoresis and a study on their inclusion interactions with β-cyclodextrin and derivatives

Azhari NR, Yahaya N, Mohd Suah FBM, Prabu S, Yih Hui B, Shahriman MS, et al.

Chirality, 2021 01;33(1):37-50.
PMID: 33197086 DOI: 10.1002/chir.23285

A chiral separation method coupled with capillary electrophoresis (CE) analysis for ketoconazole and miconazole enantiomers using chiral selectors such as β-cyclodextrin (β-CD) and hydroxypropyl-β-CD (HP-β-CD) was developed in this study, which included the optimisation, validation and application of the method on the antifungal cream samples. The formation of inclusion complex between the hosts (β-CD and HP-β-CD) and guests (ketoconazole and miconazole) were compared and analysed using ultraviolet-visible spectrophotometry, nuclear magnetic resonance (NMR) spectroscopy and molecular docking methods. Results from the study showed that in a concentration that ranged between 0.25 and 50 mg L-1 , the linear calibration curves of each enantiomer had a high coefficient of regression (R2 > 0.999), low limit of detection (0.075 mg L-1 ) and low limit of quantification (0.25 mg L-1 ). The relative standard deviation (RSD) of the intraday and interday analyses ranged from 0.79% to 8.01% and 3.30% to 11.43%, respectively, while the recoveries ranged from 82.0% to 105.7% (RSD < 7%, n = 3). The most probable structure of the inclusion complexes was proposed based on the findings from the molecular docking studies conducted using the PatchDock server.

Matched MeSH terms: Spectrophotometry
Health risks assessment diagnosis of toxic chemicals (heavy metals) via food crops consumption irrigated with wastewater

Khan MA, Mehmood S, Ullah F, Khattak A, Zeb MA

Sains Malaysiana, 2017;46:917-924.

The present study investigated the concentration of metals in commonly grown vegetables (Luffa acutangula L., Zea mays L., Solanum melongena L.) irrigated with waste water in District Bannu, Khyber Pakhtunkhwa, Pakistan. The pH (5.80) and electrical conductivity (13 dS/m) of waste water indicated the acidic nature that is not suitable for irrigation purposes. Soil and vegetables samples were analyzed for metals concentration through flame atomic absorption spectrometry (Varian FAAS-240). The findings showed that waste water irrigated soil was highly contaminated with Cd (4.62 mg/kg) which was above permissible limits set by European Union Standard (EU 2006, 2002). The concentrations of heavy metals such as Cr and Cd in vegetables were higher than the permissible limits set by World Health Organization/Food and Agriculture Organization U.S.A guidelines 2001. The health hazard quotient (HQ) of waste water irrigated vegetables was observed higher for Ni (0.699-0.1029 mg/kg), (0.0456-0.1040 mg/kg), (0.731-0.0994 mg/kg) in Luffa acutangula, Solanum melongena and Zea mays, respectively. The study concluded that the consumption of commonly grown vegetables in waste water zone of the study area may pose potential health threats in local population.

Matched MeSH terms: Spectrophotometry, Atomic
Toxic heavy metal (Pb and Cd) content in tobacco cigarette brands in Selangor state, Peninsular Malaysia

Janaydeh M, Ismail A, Zulkifli SZ, Omar H

Environ Monit Assess, 2019 Sep 16;191(10):637.
PMID: 31529162 DOI: 10.1007/s10661-019-7755-y

Cadmium (Cd) and lead (Pb) are ubiquitous metals widely distributed in the environment, resulting in toxic health effects. This project aims to evaluate Pb and Cd as toxic elements in 15 different tobacco cigarette brands produced and/or sold in Selangor state, Peninsular Malaysia. The concentrations of Pb and Cd in all tobacco brands tested in this study were determined using the air-acetylene flame atomic absorption spectrophotometer (AAS). On average, the concentrations of Pb and Cd in different tobacco brand samples ranged from 3.05 and 0.80 μg/g dw, respectively. The results indicate that assessment mean values of Pb inhaled from smoking one packet of 20 cigarettes were in the range of 1.55-3.51 μg. Furthermore, the concentration of Cd inhaled per packet of cigarettes (20 sticks) is estimated to be 0.04-0.36 μg. However, there was a significant difference in the concentrations of Pb and Cd between the different brands of tobacco cigarettes, among cigarette prices (cheap versus expensive) of tobacco brands. In conclusion, cigarette smokers in Selangor, Malaysia, are heavily exposed to Pb and Cd, and such exposure could adversely affect their health in the long term. The impact of toxic heavy metals on smokers in this state would be an area for future research.

Matched MeSH terms: Spectrophotometry, Atomic
Experimental and first-principles DFT studies on the band gap behaviours of microsized and nanosized Zn(1-x)MnxO materials

Kasim MF, Darman AKAB, Yaakob MK, Badar N, Kamarulzaman N

Phys Chem Chem Phys, 2019 Sep 11;21(35):19126-19146.
PMID: 31432825 DOI: 10.1039/c9cp01664c

In this study, nano- and microsized zinc oxide (ZnO) materials were doped with different manganese (Mn) contents (1-5 mol%) via a simple sol-gel method. The structural, morphological, optical and chemical environments of the materials were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), UV-visible spectroscopy (UV-vis) and X-ray photoelectron spectroscopy (XPS). XRD results revealed that all synthesised materials were pure and single phased with a hexagonal wurtzite structure of ZnO. However, at a low annealing temperature, a nanorod-like shape can be obtained for all Zn(1-x)MnxO materials. In addition, EDX spectra confirmed the presence of Mn in the ZnO lattice and the atomic percentage was nearly equal to the calculated stoichiometry. UV-vis spectroscopy further revealed that materials in nano size exhibited band gap widening with an increase of the Mn content in the ZnO lattice. In contrast, micron state materials exhibited band gap narrowing with increasing Mn content up to 3% and then begin to widen when Mn > 3%. This is because the band gaps of these materials are affected by the dimensions of the crystals and the Mn content in the materials. Furthermore, XPS results revealed the existence of multiple states of Mn in all synthesised materials. By combining the information obtained from UV-vis and the XPS valence band, shifting in the valence band maximum (VBM) and conduction band minimum (CBM) was observed. Based on XPS results, the calculation of density functional theory studies revealed that the presence of Mn2+, Mn3+, and Mn4+ ions in the materials influences the band gap changes. It was also revealed that the nanosized Zn0.99Mn0.01O exhibited a higher photocatalytic activity than the other samples for degrading methylene blue (MB) dyes, owing to its smallest crystallite size.

Matched MeSH terms: Spectrophotometry, Ultraviolet
In vivo study on the release of nickel, chromium, and zinc in saliva and serum from patients treated with fixed orthodontic appliances

Quadras DD, Nayak USK, Kumari NS, Priyadarshini HR, Gowda S, Fernandes B

Dent Res J (Isfahan), 2019 7 16;16(4):209-215.
PMID: 31303873

Background: Fixed orthodontic appliances can release metal ions such as nickel, chromium, and zinc into saliva and blood, which can cause contact dermatitis, hypersensitivity, and cytotoxicity. This study was undertaken to assess the release of nickel, chromium, and zinc in saliva and serum of patients undergoing fixed orthodontic treatment.
Materials and Methods: This in vivo study was conducted on 80 participants with an age range of 15-40 years. Thirty were included as controls and 50 participants were treated with fixed orthodontic appliances. Saliva and blood samples were collected at five different periods, before insertion of fixed orthodontic appliance and at 1 week, 3 months, 1 year, and 1.5 years after insertion of appliance, respectively. The metal ion content in the samples were analyzed by atomic absorption spectrophotometry. Mean levels of nickel, chromium, and zinc in saliva and serum were compared between groups using independent sample t-test and before and after results using paired t-test. P < 0.05 was considered as statistically significant.
Results: At the end of 1.5 years, the mean salivary levels of nickel, chromium, and zinc in controls were 5.02 ppb, 1.27 ppb, and 10.24 ppb, respectively, as compared to 67 ppb, 30.8 ppb, and 164.7 ppb at the end of 1.5 years. This was statistically significant with P < 0.001. A significant increase in the metal ion levels were seen in participants with before and after insertion of appliance (P < 0.001).
Conclusion: Orthodontic appliances do release considerable amounts of metal ions such as nickel, chromium, and zinc in saliva and serum. However, it was within permissible levels and did not reach toxic levels.

Matched MeSH terms: Spectrophotometry, Atomic
Fulltext The UV spectroscopic and chromatographic methods of hydroalcoholic extracts of Aloe vera

Kathleen J. Jalani, Razuan Hilmi Md Sulji, Hannis Fadzillah Mohsin, Ibtisam Abdul Wahab

ESTEEM Academic Journal, 2019;15(1):18-24.
MyJurnal

Aloe vera which is also known as Aloe barbadensis Miller,is a plant that is commonly used for medicinal purposes and as treatments for various health issues. It produces two substances; gel and latex, which are used for commercial household products, halal food and cosmetics. Aloe gel is the clear, jelly-like substance found in the inner part of the Aloe leaf while Aloe’s yellow latex comes from the peel. Aloe vera is able to provide therapeutic effects such as wound healing, anti-inflammatory, antioxidant, laxative and antimicrobial properties. The objective of this study was to
investigate the extracts via spectrophotometry (λ = 200 – 400 nm) and liquid chromatography. After 21 days, the ultraviolet spectra showed the evidence of the water molecules interactions and the hydroxyl groups in hydroalcoholic extracts. Significant peaks were also observed in the chromatograms. Further studies evaluating the stability of A. vera extracts should be carried out.

Matched MeSH terms: Spectrophotometry
Fulltext Role of Sintering Temperature in Production of Nepheline Ceramics-Based Geopolymer with Addition of Ultra-High Molecular Weight Polyethylene

Ahmad R, Abdullah MMAB, Ibrahim WMW, Hussin K, Ahmad Zaidi FH, Chaiprapa J, et al.

Materials (Basel), 2021 Feb 25;14(5).
PMID: 33669116 DOI: 10.3390/ma14051077

The primary motivation of developing ceramic materials using geopolymer method is to minimize the reliance on high sintering temperatures. The ultra-high molecular weight polyethylene (UHMWPE) was added as binder and reinforces the nepheline ceramics based geopolymer. The samples were sintered at 900 °C, 1000 °C, 1100 °C, and 1200 °C to elucidate the influence of sintering on the physical and microstructural properties. The results indicated that a maximum flexural strength of 92 MPa is attainable once the samples are used to be sintered at 1200 °C. It was also determined that the density, porosity, volumetric shrinkage, and water absorption of the samples also affected by the sintering due to the change of microstructure and crystallinity. The IR spectra reveal that the band at around 1400 cm-1 becomes weak, indicating that sodium carbonate decomposed and began to react with the silica and alumina released from gels to form nepheline phases. The sintering process influence in the development of the final microstructure thus improving the properties of the ceramic materials.

Matched MeSH terms: Spectrophotometry, Infrared
Lead contamination in Eugenia dyeriana herbal preparations from different commercial sources in Malaysia

Ang HH

Food Chem Toxicol, 2008 Jun;46(6):1969-75.
PMID: 18328612 DOI: 10.1016/j.fct.2008.01.037

The Drug Control Authority (DCA) of Malaysia implemented the phase three registration of traditional medicines on 1 January, 1992. A total of 100 products in various pharmaceutical dosage forms of a herbal preparation, containing Eugenia dyeriana, either single or combined preparations (more than one medicinal plant), were analyzed for the presence of lead contamination, using atomic absorption spectrophotometry. These samples were bought from different commercial sources in the Malaysian market, after performing a simple random sampling. Results showed that 22% of the above products failed to comply with the quality requirement for traditional medicines in Malaysia. Although this study showed that 78% of the products fully complied with the quality requirement for traditional medicines in Malaysia pertaining to lead, however, they cannot be assumed safe from lead contamination because of batch-to-batch inconsistency.

Matched MeSH terms: Spectrophotometry, Atomic
Fulltext Optimization and Validation of RP-HPLC-UV/Vis Method for Determination Phenolic Compounds in Several Personal Care Products

Akkbik M, Assim ZB, Ahmad FB

Int J Anal Chem, 2011;2011:858153.
PMID: 21760792 DOI: 10.1155/2011/858153

An HPLC method with ultraviolet-visible spectrophotometry detection has been optimized and validated for the simultaneous determination of phenolic compounds, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) as antioxidants, and octyl methyl cinnamate (OMC) as UVB-filter in several personal care products. The dynamic range was between 1 to 250 mg/L with relative standard deviation less than 0.25% (n = 4). Limits of detection for BHA, BHT, and OMC were 0.196, 0.170, and 0.478 mg/L, respectively. While limits of quantification for BHA, BHT, and OMC were 0.593, 0.515, and 1.448 mg/L, respectively. The recovery for BHA, BHT, and OMC was ranged from 92.1-105.9%, 83.2-108.9%, and 87.3-103.7%, respectively. The concentration ranges of BHA, BHT, and OMC in 12 commercial personal care samples were 0.13-4.85, 0.16-2.30, and 0.12-65.5 mg/g, respectively. The concentrations of phenolic compounds in these personal care samples were below than maximum allowable concentration in personal care formulation, that is, 0.0004-10 mg/g, 0.002-5 mg/g, and up to 100 mg/g for BHA, BHT, and OMC, respectively.

Matched MeSH terms: Spectrophotometry, Ultraviolet
Physicochemical Properties, Minerals, Trace Elements, and Heavy Metals in Honey of Different Origins: A Comprehensive Review

Solayman M, Islam MA, Paul S, Ali Y, Khalil MI, Alam N, et al.

Compr Rev Food Sci Food Saf, 2016 Jan;15(1):219-233.
PMID: 33371579 DOI: 10.1111/1541-4337.12182

Honey is a popular natural food product with a very complex composition mainly consisting of both organic and inorganic constituents. The composition of honey is strongly influenced by both natural and anthropogenic factors, which vary based on its botanical and geographical origins. Although minerals and heavy metals are minor constituents of honey, they play vital role in determining its quality. There are several different analytical methods used to determine the chemical elements in honey. These methods are typically based on spectroscopy or spectrometry techniques (including atomic absorption spectrometry, atomic emission spectrometry, inductively coupled plasma mass spectrometry, and inductively coupled plasma optical emission spectrometry). This review compiles available scientific information on minerals and heavy metals in honey reported from all over the world. To date, 54 chemical elements in various types of honey have been identified and can be divided into 3 groups: major or macroelements (Na, K, Ca, Mg, P, S, Cl), minor or trace elements (Al, Cu, Pb, Zn, Mn, Cd, Tl, Co, Ni, Rb, Ba, Be, Bi, U, V, Fe, Pt, Pd, Te, Hf, Mo, Sn, Sb, La, I, Sm, Tb, Dy, Sd, Th, Pr, Nd, Tm, Yb, Lu, Gd, Ho, Er, Ce, Cr, As, B, Br, Cd, Hg, Se, Sr), and heavy metals (trace elements that have a specific gravity at least 5 times higher than that of water and inorganic sources). Chemical elements in honey samples throughout the world vary in terms of concentrations and are also influenced by environmental pollution.

Matched MeSH terms: Spectrophotometry, Atomic
Fulltext Transparent Blend of Poly(Methylmethacrylate)/Cellulose Acetate Butyrate for the Protection from Ultraviolet

Mahmood Raouf R, Abdul Wahab Z, Azowa Ibrahim N, Abidin Talib Z, Chieng BW

Polymers (Basel), 2016 Apr 14;8(4).
PMID: 30979233 DOI: 10.3390/polym8040128

The use of transparent polymers as an alternative to glass has become widespread. However, the direct exposure of these materials to climatic conditions of sunlight and heat decrease the lifetime cost of these products. The aim of this study was to minimize the harm caused by ultraviolet (UV) radiation exposure to transparent poly(methylmethacrylate) (PMMA), which usually leads to changes in the physical and chemical properties of these materials and reduced performance. This was achieved using environmentally friendly cellulose acetate butyrate (CAB). The optical, morphological, and thermal properties of CAB blended with transparent PMMA was studied using UV-VIS spectrophotometry, scanning electron microscopy, X-ray diffraction, dynamic mechanical analysis, and thermal gravimetric analysis. The results show that CAB was able to reduce the effects of UV radiation by making PMMA more transparent to UV light, thereby preventing the negative effects of trapped radiation within the compositional structure, while maintaining the amorphous structure of the blend. The results also show that CAB blended with PMMA led to some properties commensurate with the requirements of research in terms of a slight increase in the value of the modulus and the glass transition temperature for the PMMA/CAB blend.

Matched MeSH terms: Spectrophotometry

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