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Dangombe MS, Oladepo SA. Investigation of solute-solvent interactions of 4'-alkyl-4-cyanobiphenyl liquid crystals using Raman spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 312:124067. [PMID: 38422937 DOI: 10.1016/j.saa.2024.124067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/06/2024] [Accepted: 02/19/2024] [Indexed: 03/02/2024]
Abstract
Liquid crystal materials possess hybrid liquid and solid-like properties with high response to stimuli. The 4'-alkyl-4-cyanobiphenyls (nCB) are an important class of liquid crystals that are widely used for various applications. In this study, six alkylcyanobiphenyl liquid crystal samples (5CB to 10CB) were examined using Raman spectroscopy in a total of twelve solvents of various polarities. The distinctive bands contributed by the LC sample are from C≡N stretch, C-C aromatic ring breathing, C-C biphenyl linking stretch, and C-H in-plane deformation. These modes are found to be responsive to different solvent environments by shifting positions. For instance, the cyano stretching mode of 5CB is blue-shifted from 2229 cm-1 for the pure sample to 2233 cm-1 when measured in hexane due to the repulsive interaction between the mode and the solvent bath. On the other hand, this mode undergoes a red-shift to 2220 cm-1 in methanol due to hydrogen bond interaction between the mode and solvent molecules. Overall, the shift in the position of the vibrational modes of nCB molecules was correlated with solvent properties such as acceptor number, donor number, and Kamlet-Taft dipolarity constants, which are a measure of solvent polarity. In samples with longer alkyl chains (8CB, 9CB, and 10CB), the wavenumber of the stretching modes was generally shifted to around the same position in all the solvents. Such observations are related to the folding back effect and enhanced dimerization constant with an increase in the chain length.
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Affiliation(s)
- Musa S Dangombe
- Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia; Interdisciplinary Research Center for Advanced Materials (IRC-AM), King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
| | - Sulayman A Oladepo
- Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia; Interdisciplinary Research Center for Advanced Materials (IRC-AM), King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia.
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Dias Santos J, Pinto PF, Edwards HGM, Cappa de Oliveira LF. Characterization by Raman and infrared spectroscopy and fluorescence microscopy of human hair treated with cosmetic products. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 280:121577. [PMID: 35792483 DOI: 10.1016/j.saa.2022.121577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 06/28/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
Analytical studies on hair structures have evolved significantly over the years and vibrational spectroscopic techniques, such as Raman and infrared, have been increasingly used for such purposes. Nowadays, there is a need to understand more and more about the action of cosmetics on the hair fiber, so this work aims to analyze the permeation of cosmetic treatments into the hair. For the molecular structural characterization, Raman and infrared spectroscopy techniques were used, being verified the efficiency in the analysis of hair samples, demonstrating the internal characteristics of the fiber and the permeation of different cosmetics. Four cosmetics were chosen for this study and, due to the techniques used, it was possible to observe the diffusion of these products inside the bleached hair. It was observed with the Raman vibrational spectroscopy that the concentration of the products is found mainly in the cuticular region, decreasing the permeate content when approaching the central region, and the infrared spectroscopy showed results compatible with the Raman spectroscopy. Therefore, vibrational spectroscopy proved to be a valuable tool for the study of cosmetic permeation into the hair fiber and for the analysis of its external and internal structure.
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Affiliation(s)
- Jordana Dias Santos
- Núcleo de Espectroscopia e Estrutura Molecular, Departamento de Química, Universidade Federal de Juiz de Fora, Juiz de Fora 36036-900, MG, Brazil
| | - Priscila F Pinto
- Departamento de Bioquímica, Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora 36036-900, MG, Brazil
| | - Howell G M Edwards
- School of Chemistry and Biosciences, Faculty of Life Sciences, University of Bradford, Bradford, West Yorkshire BD7 1DP, United Kingdom
| | - Luiz F Cappa de Oliveira
- Núcleo de Espectroscopia e Estrutura Molecular, Departamento de Química, Universidade Federal de Juiz de Fora, Juiz de Fora 36036-900, MG, Brazil.
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do Nascimento DS, Volpe V, Fernandez C, Oresti M, Ashton L, Grünhut M. Confocal Raman spectroscopy assisted by chemometric tools: A green approach for classification and quantification of octyl p-methoxycinnamate in oil-in-water microemulsions. Microchem J 2022. [DOI: 10.1016/j.microc.2022.108151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Angrish A, Kumar R, Chauhan R, Sharma V. On the IR spectroscopy and chemometric based rapid and non-destructive method for the investigation of sunscreen stains: Application in forensic science. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 242:118708. [PMID: 32731143 DOI: 10.1016/j.saa.2020.118708] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/12/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
Cosmetic products such as sunscreens may often be encountered in forensic investigations as traces left on tissue paper, apparels, drinkware, painted exterior, or various alternative surfaces. The pilot study aimed at efficiently using Infrared spectroscopy coupled with chemometrics to cater to unbiased, rapid, and non-destructive identification of sunscreens which will aid various forensic investigations soon. In the present research, a total of 109 sunscreen samples were analyzed using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy. The physicochemical data from the FTIR instrument was then subjected to principal component analysis (PCA), which successfully distinguished most of the samples based on their spectral information. The trained model resulted in clear segregation of unknown sunscreen samples. This could provide an outstanding level of confidence during the conduction of 'questioned versus known' comparisons of similar sunscreens and will give the details of the manufacturer, thereby, helping in rounding off the suspects.
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Affiliation(s)
- Arpita Angrish
- Institute of Forensic Science & Criminology, Panjab University, Chandigarh 160014, India
| | - Raj Kumar
- Institute of Forensic Science & Criminology, Panjab University, Chandigarh 160014, India
| | - Rohini Chauhan
- Institute of Forensic Science & Criminology, Panjab University, Chandigarh 160014, India
| | - Vishal Sharma
- Institute of Forensic Science & Criminology, Panjab University, Chandigarh 160014, India.
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Sensitive Synchronous Spectrofluorimetric Study of Certain Sunscreens Using Fluorescence Enhancers in Cosmeceutical Formulations. J Fluoresc 2018; 28:491-504. [PMID: 29344769 DOI: 10.1007/s10895-017-2206-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Accepted: 12/20/2017] [Indexed: 10/18/2022]
Abstract
Synchronous spectrofluorimetric methods could be successfully adopted for simultaneous determination of Octinoxate (OMC), Avobenzone (AVO), Octyltriazone (OT), and Phenyl benzimidazole sulfonic acid (PBSA) in moisturizing sunscreen lotion, utilizing β-CD as fluorescence enhancer, and determination of Avobenzone (AVO), Homosalate, Tinosorb M and Phenyl benzimidazole sulfonic acid (PBSA) in presence of Octocrylene (OCR) in whitening sunscreen cream, using micellar medium of Sodium Dodecyl Sulfate (SDS) to enhance fluorescence intensity. For first product, zero order synchronous spectrofluorimetric method was used for determination of OMC and AVO, and derivative synchronous spectrofluorimetric technique was utilized for OT and PBSA in quaternary mixture. Linear calibration curves were obtained in a concentration range of 0.5-8 μg mL- 1 for OMC and AVO, and in range of 0.05-3 μg mL- 1 for OT and 0.001-5 μg mL- 1 for PBSA, by measuring the fluorescence at 370, 405, 333.2 and 340.6 nm, respectively. For second product, first derivative synchronous fluorescence method was used for each UV-filter. A linear calibration curves were obtained in a concentration range of 0.5-8 μg mL- 1 for AVO, in range of 0.1-8 μg mL- 1 for Homosalate, 2-10 μg mL- 1 for Tinosorb M and 0.001-5 μg mL- 1 for PBSA, by measuring the fluorescence at 409.8, 373, 307.2 and 316.8 nm, respectively. The detection limits are well below the maximum admissible concentration. The proposed methods were validated according to ICH guidelines and successfully applied to determine sunscreens in pure form and in Cosmeceutical formulations. All the results obtained were compared with those of published methods, where no significant difference was observed.
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Sobanska A, Brzezinska E. Simultaneous NP TLC analysis of the sunscreens diethylamino hydroxybenzoyl hexyl benzoate and octyl methoxycinnamate. JPC-J PLANAR CHROMAT 2011. [DOI: 10.1556/jpc.24.2011.3.10] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Oladepo SA, Loppnow GR. Initial Excited-State Structural Dynamics of 9-Methyladenine from UV Resonance Raman Spectroscopy. J Phys Chem B 2011; 115:6149-56. [DOI: 10.1021/jp1095294] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Sulayman A. Oladepo
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Glen R. Loppnow
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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Liu T, Wu D. Simultaneous determination of some ultraviolet-absorbing chemicals in sunscreen cosmetics using a high-performance liquid chromatography method. Int J Cosmet Sci 2011; 33:408-15. [PMID: 21401649 DOI: 10.1111/j.1468-2494.2011.00643.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A method of gradient elution high-performance liquid chromatography (HPLC) for simultaneous determination of 11 different ultraviolet-absorbing chemicals of phenylbenzlmldazole sulphonic acid, 4-aminobenzoic acid, benzophenone-4, benzophenone-3, isoamyl p-methoxycinnamate, 4-methylbenzylidene camphor, octocrylene, ethylhexyl methoxycinnamate, homosalate, ethylhexyl salicylate, methylene bis-benzotriazolyl tetramethylbutyl phenol was developed for the application to sunscreen cosmetic products. In this study, an Agilent SB-C18 analytical column (250 × 4.6 mm, 5 μm) was utilized and methanol, tetrahydrofuran and perchloric acid aqueous solution (0.2 mL HClO(4) + 300 mL H(2)O) were used for gradient elution at a total flow rate of 1.0 mL min(-1). The optimum conditions for 11 different ultraviolet-absorbing chemicals analyses were investigated. All calibration curves showed good linear regression with UV detection (311 nm) within test ranges. The correlation coefficients were better than 0.999 in all cases. The assay was simple, selective, convenient and reproducible and is suitable for the determination of ultraviolet-absorbing chemicals in commercial sunscreen cosmetic products. The use frequency of 11 different ultraviolet absorbents in 100 sunscreen cosmetics was investigated and statistically analysed. The ultraviolet absorbent of maximum use frequency was ethylhexyl methoxycinnamate.
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Affiliation(s)
- T Liu
- China National Cosmetics Quality Supervision & Inspection Center, Beijing 100094, China.
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Lourenço ND, Paixão F, Pinheiro HM, Sousa A. Use of spectra in the visible and near-mid-ultraviolet range with principal component analysis and partial least squares processing for monitoring of suspended solids in municipal wastewater treatment plants. APPLIED SPECTROSCOPY 2010; 64:1061-1067. [PMID: 20828444 DOI: 10.1366/000370210792434332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The present work assesses the possibility of using spectrophotometry in the near-mid-ultraviolet and visible wavelength ranges (282-790 nm) for the direct monitoring of treatment performance in municipal wastewater treatment plants (WWTPs). Principal component analysis (PCA) was used to analyze spectral data from samples collected along three WWTP process lines with different primary and secondary treatment units. The clustering observed in PCA score plots was mainly attributed to the suspended solids fraction present in the wastewater and highlighted differences in solids quality between plants and along the treatment lines. Thus, satisfactory partial least squares (PLS) calibration models to estimate total suspended solids (TSS) values from the acquired spectra could only be established per plant. The PLS models were established using 1-2 factors, with root mean error of cross-validation and coefficient of determination values in the 50-86 mg TSS L(-1) and 82-95% ranges, respectively.
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Affiliation(s)
- Nídia D Lourenço
- Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Technical University of Lisbon, Av. Rovisco Pais 1049-001 Lisbon, Portugal.
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