Journal of Spectroscopy The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Emission Spectroscopy of OH Radical in Water-Argon Arc Plasma Jet Mon, 07 Apr 2014 08:27:27 +0000 Emission spectra of OH radical are studied in the plasma jet generated by a plasma torch with hybrid water-argon stabilization. Plasma jet is located in a chamber with pressures 4 kPa and 10 kPa. In spite of high temperatures of produced plasma, OH spectra are observed in a large area of the jet. OH spectra are used to obtain rotational temperatures from the Boltzmann plots of resolved rotational lines. Due to line-of-sight integration of radiation, interpretation of the temperatures is not straightforward. It seems that excited OH molecules can be formed by various mechanisms, mainly in the outer parts of the jet, where thermal processes are not as dominant as in the hot central region. Alan Mašláni and Viktor Sember Copyright © 2014 Alan Mašláni and Viktor Sember. All rights reserved. Interaction of Warfarin with Human Serum Albumin and Effect of Ferulic Acid on the Binding Thu, 13 Mar 2014 16:46:29 +0000 Angelica sinensis (Oliv.) Diels combined treatment with warfarin would increase the risk of bleeding. Ferulic acid is an abundant hydroxycinnamic acid in A. sinensis and warfarin is the most widely used oral anticoagulant. The studies on supermolecular interaction of warfarin with human serum albumin (HSA) and the influence of ferulic acid on the binding would contribute to the understanding of the metabolic processes of warfarin and the effect of ferulic acid. We focus on investigating the effect of warfarin on fluorescence spectrum of human serum albumin (HSA), fluorescence quenching mechanism, binding constant, Hill coefficient, binding mode, and the effect of different ferulic acid concentrations on the binding. Warfarin quenched the intrinsic fluorescence of HSA mainly by static quenching. Accession of ferulic acid reduced the binding of HSA-warfarin. By decreasing binding constant and the Hill coefficient of warfarin with HSA, ferulic acid could improve the plasma concentration of free warfarin, which would increase the risk of bleeding. Warfarin’s free concentration increased at least 50% under the condition of simulated human body. The results indicated that A. sinensis combined treatment with warfarin would increase the risk of bleeding. And the results provide an important theoretical support for warfarin used as oral anticoagulant. Qiang Li, Wen-yue Yang, Ling-ling Qu, Huan-Yang Qi, Yun Huang, and Zheng Zhang Copyright © 2014 Qiang Li et al. All rights reserved. Determination of Muscone in Rats Plasma following Oral Administration of Artificial Musk: Using of Combined Headspace Gas Chromatography-Mass Spectrometry Sun, 23 Feb 2014 06:56:31 +0000 To develop an analytical method for determination of plasma concentrations of muscone in rats following oral administration of artificial musk, with the aim of investigating the pharmacokinetic profile of artificial musk. Plasma samples were pretreated with acetonitrile to precipitate proteins. Headspace injection coupled with gas chromatography-mass spectrometry was used for quantitative analysis of muscone concentrations. A strong linear relationship was obtained for plasma muscone concentrations ranging from 75.6 to 7560 ng·mL−1  , with the minimum detectable concentration being 25 ng·mL−1. The within-day and interday precision for determination of three different concentrations of muscone were favorable (RSD < 25%). The average absolute recovery ranged from 83.7 to 88.6%, with an average relative recovery of 100.5 to 109.8%. The method described was characterized by stability and reliability, and in the present study showed significant specificity and high sensitivity. This method would be applicable to the analysis of plasma concentrations of muscone in preclinical contexts, where artificial musk is used. Qibiao Wu, Haitao Li, Yujing Leng, Haishan Deng, Haibo Cheng, and Weixing Shen Copyright © 2014 Qibiao Wu et al. All rights reserved. Heliograph Imaging Based on Total Variation Constraint and Nonlocal Operator Wed, 19 Feb 2014 13:02:25 +0000 Heliograph imaging is the process to reconstruct the solar image from sparse frequency domain data, and compressed sensing (CS) algorithm has shown potential power to accurately recover images from highly undersampled data. However, the available compressed sensing based models available for heliograph imaging are not able to reconstruct fine solar structures and often suffer from undesired convolutive artifacts. This paper presents an imaging model with total variation constraint and nonlocal operator based on compressed sensing theory, with particular objective to suppress convolutive artifacts and reconstruct fine structures. In particular, an efficient algorithm is presented to solve the formulated model. Finally, a set of simulations has been conducted by using both synthetic and real images, and the results demonstrate that our proposed algorithm has surprisingly lower reconstruction errors than other methods. S. Z. Wang, L. Y. Xu, Y. Wang, and X. P. Zhang Copyright © 2014 S. Z. Wang et al. All rights reserved. Terahertz Absorption Spectroscopy of Benzamide, Acrylamide, Caprolactam, Salicylamide, and Sulfanilamide in the Solid State Sun, 16 Feb 2014 15:09:10 +0000 Terahertz (THz) absorption spectra of the similarly structured molecules with amide groups including benzamide, acrylamide, caprolactam, salicylamide, and sulfanilamide in the solid phase at room temperature and 7.8 K for salicylamide are reported and compared to infrared vibrational spectral calculations using density functional theory. The results of THz absorption spectra show that the molecules have characteristic bands in the region of 0.2–2.6 THz (~7–87 cm−1). THz technique can be used to distinguish different molecules with amide groups. In the THz region benzamide has three bands at 0.83, 1.63, and 1.73 THz; the bands are located at 1.44 and 2.00 THz for acrylamide; the bands at 1.24, 1.66 and 2.12 THz are observed for caprolactam. The absorption bands are located at 1.44, 1.63, and 2.39 THz at room temperature, and at 1.22, 1.46, 1.66, and 2.41 THz at low temperature for salicylamide. The bands at 1.63, 1.78, 2.00, and 2.20 THz appear for sulfanilamide. These bands in the THz region may be related to torsion, rocking, wagging, and other modes of different groups in the molecules. Ye Jiang, Fengshan Zhou, Xiaodong Wen, Limin Yang, Guozhong Zhao, He Wang, Haiyan Wang, Yanjun Zhai, Jinguang Wu, Kexin Liu, and Jia’er Chen Copyright © 2014 Ye Jiang et al. All rights reserved. Nondestructive Discrimination of Lead (Pb) in Preserved Eggs (Pidan) by Near-Infrared Spectroscopy and Chemometrics Mon, 10 Feb 2014 13:06:02 +0000 A major safety concern with pidan (preserved eggs) has been the usage of lead (II) oxide (PbO) during its processing. This paper develops a rapid and nondestructive method for discrimination of lead (Pb) in preserved eggs with different processing methods by near-infrared (NIR) spectroscopy and chemometrics. Ten batches of 331 unleaded eggs and six batches of 147 eggs processed with usage of PbO were collected and analyzed by NIR spectroscopy. Inductively coupled plasma mass spectrometry (ICP-MS) analysis was used as a reference method for Pb identification. The Pb contents of leaded eggs ranged from 1.2 to 12.8 ppm. Linear partial least squares discriminant analysis (PLSDA) and nonlinear least squares support vector machine (LS-SVM) were used to classify samples based on NIR spectra. Different preprocessing methods were studied to improve the classification performance. With second-order derivative spectra, PLSDA and LS-SVM obtained accurate and reliable classification of leaded and unleaded preserved eggs. The sensitivity and specificity of PLSDA were 0.975 and 1.000, respectively. Because the strictest safety standard of Pb content in traditional pidan is 2 ppm, the proposed method shows the feasibility for rapid and nondestructive discrimination of Pb in Chinese preserved eggs. Lu Xu, Si-Min Yan, Chen-Bo Cai, and Xiao-Ping Yu Copyright © 2014 Lu Xu et al. All rights reserved. Interaction of Bradykinin and B2 Bradykinin Receptor Antagonists with Colloidal Au Surface Explored by Surface-Enhanced Raman Scattering Tue, 04 Feb 2014 14:00:53 +0000 Bradykinin (BK), an endogenous peptide hormone, which is involved in a number of physiological and pathophysiological processes, and the potent B2 bradykinin receptor antagonists, [D-Arg0,Hyp3,Thi5,8,L-Pip7]BK, Aaa[D-Arg0,Hyp3,Thi5,8,L-Pip7]BK, [D-Arg0,Hyp3,Thi5,D-Phe7,L-Pip8]BK, and Aaa[D-Arg0,Hyp3,Thi5,D-Phe7,L-Pip8]BK, were deposited onto colloidal Au particles of 20 nm size. Interaction of these molecules with colloidal Au surface was explored by surface-enhanced Raman scattering (SERS). Briefly, it was shown that BK adsorbs on the Au surface mainly through the Phe5/Phe8 residues. In case of the BK specifically modified analogues mainly the Pip and Thi rings are involved in the interaction process; however, Pip and Thi adopt slightly different orientation with respect to Au for each of the analogues. In addition, the lack of the Aaa vibrations, together with the enhancement of the Thi, Pip, or Phe modes, emphasizes the importance of the C-terminus in the interaction with the Au surface. Dominika Skołuba, Dariusz Sobolewski, Adam Prahl, and Edyta Proniewicz Copyright © 2014 Dominika Skołuba et al. All rights reserved. Kinetic Spectrophotometric Determination of Gemifloxacin Mesylate and Moxifloxacin Hydrochloride in Pharmaceutical Preparations Using 4-Chloro-7-nitrobenzo-2-oxa-1,3-diazole Mon, 03 Feb 2014 11:08:49 +0000 Simple, sensitive, and accurate kinetic spectrophotometric method was proposed for the determination of gemifloxacin mesylate (GMF) and moxifloxacin hydrochloride (MOX) in pure forms and pharmaceutical preparations (tablets). The method is based on coupling the studied drugs with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) in the presence of alkaline borate buffer. Spectrophotometric measurement was achieved by recording the absorbance at 466 and 464 nm for GMF and MOX, respectively, after a fixed time of 20 and 15 min on a water bath adjusted at 70 ± 5°C for both drugs. The different experimental parameters affecting the development and stability of the color were carefully studied and optimized. The absorbance-concentration plots were linear over the ranges 0.5–8.0 and 2.0–12 μg mL−1 for GMF and MOX, respectively. The limit of detection of the kinetic method was about 0.12 (2.47 × 10−7 M) and 0.36 (8.22 × 10−7 M) μg mL−1 for GMF and MOX, respectively. The proposed methods have been applied and validated successfully with percentage relative standard deviation (RSD% ≤ 0.52) as precision and percentage relative error (RE% ≤ 1.33) as accuracy. The robustness of the proposed method was examined with recovery values that were 97.5–100.5 ± 1.3–1.9%. Statistical comparison of the results with the reference spectrophotometric methods shows excellent agreement and indicates no significant difference in accuracy or precision. Mohammed G. Abdel Wahed, Ragaa El Sheikh, Ayman A. Gouda, and Sayed Abou Taleb Copyright © 2014 Mohammed G. Abdel Wahed et al. All rights reserved. Analysis of an Alanine/Arginine Mixture by Using TLC/FTIR Technique Tue, 28 Jan 2014 12:10:08 +0000 We applied TLC/FTIR coupled with mapping technique to analyze an alanine/arginine mixture. Narrow band TLC plates prepared by using AgI as a stationary phase were used to separate alanine and arginine. The distribution of alanine and arginine spots was manifested by a 3D chromatogram. Alanine and arginine can be successfully separated by the narrow band TLC plate. In addition, the FTIR spectra of the separated alanine and arginine spots on the narrow band TLC plate are roughly the same as the corresponding reference IR spectra. Jun Liu, Feng-shan Zhou, Ran Guo, Ye Jiang, Xiaokun Fan, Anqi He, Yanjun Zhai, Shifu Weng, Zhanlan Yang, Yizhuang Xu, Isao Noda, and Jinguang Wu Copyright © 2014 Jun Liu et al. All rights reserved. Structure Characterization of [N-Phenylamino(2-boronphenyl)-R-methyl]phosphonic Acid by Vibrational Spectroscopy and Density Functional Theory Calculations Thu, 23 Jan 2014 13:08:10 +0000 We present the first Fourier-transform infrared absorption (FT-IR) and Fourier-transform Raman (FT-Raman) analysis of vibrational structure of [N-phenylamino(2-boronphenyl)-R-methyl]phosphonic acid ([PhN-(2-PhB(OH)2)-R-Me]PO3H2). Assignments of experimental wavenumbers are based on performed theoretical calculations using density functional theory (DFT). Theoretical calculations show that the most stable structure of the investigated molecule is dimer in cis-trans conformation created by a pair of intermolecular hydrogen bonds between the boron hydroxyl groups of two monomers. Natalia Piergies and Edyta Proniewicz Copyright © 2014 Natalia Piergies and Edyta Proniewicz. All rights reserved. SB-ATR FTIR Spectroscopic Monitoring of Free Fatty Acids in Commercially Available Nigella sativa (Kalonji) Oil Tue, 21 Jan 2014 12:04:02 +0000 Free fatty acids (FFA) in Nigella sativa (N. sativa) commercial and seed oil were determined using single-bounce attenuated total reflectance (SB-ATR) Fourier transform infrared (FTIR) spectroscopy. Gravimetrical mixing was done by adding 0.1–40% oleic acids in neutralized N. sativa oil containing 0.1% FFA. FTIR spectroscopy technique and partial least square (PLS) calibration were used to detect the absorption region of carbonyl (C=O) which is in the range of 1690–1727 cm−1. The results of PLS calibration model and root mean square error of calibration (RMSEC) are 0.999 and 0.449, respectively. Comparing the FFA obtained in N. sativa oil by using FTIR with the FFA obtained using AOCS titrimetric method shows a positive correlation and confirms that the described method is a useful procedure. S. A. Mahesar, Aftab A. Kandhro, Abdul Rauf Khaskheli, M. Y. Talpur, and S. T. H. Sherazi Copyright © 2014 S. A. Mahesar et al. All rights reserved. Synthesis and Characterization of CdS/TiO2-Montmorillonite Nanocomposite with Enhanced Visible-Light Absorption Mon, 20 Jan 2014 06:43:07 +0000 Sodium montmorillonite (MMT) was chosen as the carrier; a serial of CdS/TiO2-MMT nanocomposites with enhanced visible-light absorption ability was prepared by hydrothermal synthesis method combination with semiconductor compound modification method. The samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and ultraviolet visible (UV-Vis) spectroscopy; the results showed that TiO2 and CdS nanoparticles were loaded on the surface of montmorillonite uniformly. N2 adsorption-desorption experiment showed that the specific surface area of TiO2/montmorillonite nanocomposite made by this method can reach 200 m2/g and pore-size distribution was from 4 to 6 nm; UV-Vis showed that the recombination of CdS and TiO2 enhanced visible-light absorption ability of samples of TiO2/montmorillonite and visible-light absorption ability increase with the increased of the adsorption of CdS. Feng-shan Zhou, Dai-mei Chen, Bao-lin Cui, and Wei-heng Wang Copyright © 2014 Feng-shan Zhou et al. All rights reserved. The Use of FTIR-ATR Spectrometry for Evaluation of Surgical Resection Margin in Colorectal Cancer: A Pilot Study of 56 Samples Thu, 16 Jan 2014 13:14:14 +0000 Colorectal cancer is one of the most common malignancies in human, and it is also one of the most leading causes of cancer-related death. Recently, Fourier transform infrared (FTIR) spectrometry is considered to develop into a new method for cancer diagnosis. In this study, colorectal cancer and mucosa 1 cm, 2 cm, and 5 cm away from tumor were measured by FTIR spectroscopy. FTIR spectra of colorectal cancer and mucosa 1 cm away from tumor were different from those of mucosa 2 cm and 5 cm away from tumor. According to the analysis of FTIR spectrometry, the decrease of lipid and the increase of protein and nucleic acid were observed in the former two sites. FTIR spectrometry, therefore, may be developed into a rapid promising method for judging surgical resection margin of colorectal cancer. Hongwei Yao, Xueying Shi, and Yuanfu Zhang Copyright © 2014 Hongwei Yao et al. All rights reserved. Assessment of the Inhibitory Effect of Rifampicin on Amyloid Formation of Hen Egg White Lysozyme: Thioflavin T Fluorescence Assay versus FTIR Difference Spectroscopy Mon, 06 Jan 2014 11:16:11 +0000 The inhibitory effect of rifampicin on the amyloid formation of hen egg white lysozyme was assessed with both Thioflavin T (ThT) fluorescence assay and Fourier transform infrared (FTIR) difference spectroscopy. We reveal that ThT fluorescence assay gives a false positive result due to rifampicin interference, while FTIR difference spectroscopy provides a reliable assessment. With FTIR, we show that rifampicin only has marginally inhibitory effect. We then propose that FTIR difference spectroscopy can potentially be a convenient method for inhibitor screening in amyloid study. Gang Ma, Hong Zhang, Jianhua Guo, Xiaodan Zeng, Xiaoqian Hu, and Wenying Hao Copyright © 2014 Gang Ma et al. All rights reserved. Chemiluminescence of Mn-Doped ZnS Nanocrystals Induced by Direct Chemical Oxidation and Ionic Liquid-Sensitized Effect as an Efficient and Green Catalyst Mon, 30 Dec 2013 18:15:02 +0000 A novel chemiluminescence (CL) method was proposed for doping water-soluble Mn in ZnS quantum dots (QDs) as CL emitter. Water-soluble Mn-doped ZnS QDs were synthesized by using L-cysteine as stabilizer in aqueous solution. These nanoparticles were structurally and optically characterized by X-ray powder diffraction (XRD), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption spectroscopy, and photoluminescence (PL) emission spectroscopy. The CL of ZnS QDs was induced directly by chemical oxidation and its ionic liquid-sensitized effect in aqueous solution was then investigated. It was found that oxidants, especially hydrogen peroxide, could directly oxidize ZnS QDs to produce weak CL emission in basic solutions. In the presence of 1,3-dipropylimidazolium bromide/copper, a drastic light emission enhancement was observed which is related to a strong interaction between Cu2+ and the imidazolium ring. In these conditions, an efficient CL light was produced at low pH which is suggested to be beneficial to the biological analysis. The CL properties of QDs not only will be helpful to study physical chemistry properties of semiconductor nanocrystals but also they are expected to find use in many fields such as luminescence devices, bioanalysis, and multicolor labeling probes. Seyed Naser Azizi, Mohammad Javad Chaichi, Parmis Shakeri, Ahmadreza Bekhradnia, Mehdi Taghavi, and Mousa Ghaemy Copyright © 2013 Seyed Naser Azizi et al. All rights reserved. Conformity Check of Thickness to the Crystal Plate Sun, 29 Dec 2013 18:19:13 +0000 This work demonstrates that if crystal plates are identical in thickness in the direction of radiation, the intensity at the output of the polarizer-crystal-crystal-analyzer system equals zero. This means that it is possible to control the difference in thickness between the reference crystal plate (e.g., plates of or ) and the examined plate by the intensity of the transmitted radiation. Further, it shows that if nonmonochromatic radiation is used, then the spectrum of radiation at the output is determined by the relative orientation of the optical elements and their sizes. The paper gives the theoretical model for calculations of profile of spectra for the number of important cases of orientation of elements. Alexander Syuy, Dmitriy Shtarev, Victor Krishtop, and Natalia Kireeva Copyright © 2013 Alexander Syuy et al. All rights reserved. Environmental Method to Determine Dopamine and Ascorbic Acid Simultaneously via Derivative Spectrophotometry Wed, 25 Dec 2013 14:14:16 +0000 Many various methods were applied to determine dopamine and ascorbic acid simultaneously using hazardous materials and complex procedures. Derivative absorption spectra can give safely and five sensitive derivative equations that are used for the simultaneous determination of dopamine and ascorbic acid in the UV region, using first and second derivative spectroscopy with high precision at pH value of 9.2. Dopamine and ascorbic acid can be detected in the ranges of 0.375–9.45 mg L−1 and 0.352–5.28 mg L−1, respectively. These obtained methods could be used to determine both reagents in real and synthesized samples. Ahmed M. El-Zohry and E. Y. Hashem Copyright © 2013 Ahmed M. El-Zohry and E. Y. Hashem. All rights reserved. Simultaneous Determination of Prasugrel and Aspirin by Second Order and Ratio First Order Derivative Ultraviolet Spectrophotometry Wed, 25 Dec 2013 08:26:49 +0000 Two simple, accurate, and precise UV derivative spectrophotometric methods for the simultaneous determination of Prasugrel and Aspirin in synthetic mixture form have been developed. The first method involves measurement of second order derivative spectra of Prasugrel and Aspirin. The zero crossing wavelengths 267.62 nm and 252.40 nm were selected for estimation of Prasugrel and Aspirin, respectively. In the second method, the first order derivatives of ratio spectra were calculated and used for the determination of Prasugrel and Aspirin by measuring the peak intensity at 268 nm and 290 nm, respectively. The methods were validated as per the ICH guideline Q2 (R1). Beer’s law is followed in the range of 5–45 μg/mL for Prasugrel and 25–150 μg/mL for Aspirin by second order derivative method and 6–22 μg/mL for Prasugrel and 45–165 μg/mL for Aspirin by ratio first order derivative method. The recovery studies confirmed the accuracy of the methods. Relative standard deviations for repeatability and inter- and intraday assays were less than 2%. Hence, the described derivative spectrophotometric methods are simple, accurate, precise, and excellent alternatives to sophisticated chromatographic techniques and can be potentially used for the simultaneous determination of Prasugrel and Aspirin in combined dosage form. Shahabuddin N. Alvi, Mehul N. Patel, Prakash B. Kathiriya, Bhavna A. Patel, and Shraddha J. Parmar Copyright © 2013 Shahabuddin N. Alvi et al. All rights reserved. A New Approach to Separate Haemodynamic Signals for Brain-Computer Interface Using Independent Component Analysis and Least Squares Sun, 22 Dec 2013 08:37:07 +0000 Brain-computer interface (BCI) is one technology that allows a user to communicate with external devices through detecting brain activity. As a promising noninvasive technique, functional near-infrared spectroscopy (fNIRS) has recently earned increasing attention in BCI studies. However, in practice fNIRS measurements can suffer from significant physiological interference, for example, arising from cardiac contraction, breathing, and blood pressure fluctuations, thereby severely limiting the utility of the method. Here, we apply the multidistance fNIRS method, with short-distance and long-distance optode pairs, and we propose the combination of independent component analysis (ICA) and least squares (LS) with the fNIRS recordings to reduce the interference. The short-distance fNIRS measurement is treated as the virtual channel and the long-distance fNIRS measurement is treated as the measurement channel. Least squares is used to optimize the reconstruction value for brain activity signal. Monte Carlo simulations of photon propagation through a five-layered slab model of a human adult head were implemented to evaluate our methodology. The results demonstrate that the ICA method can separate the brain signal and interference; the further application of least squares can significantly recover haemodynamic signals contaminated by physiological interference from the fNIRS-evoked brain activity data. Yan Zhang, Xin Liu, Chunling Yang, Kuanquan Wang, Jinwei Sun, and Peter Rolfe Copyright © 2013 Yan Zhang et al. All rights reserved. Structural and Vibrational Study on Monomer and Dimer Forms and Water Clusters of Acetazolamide Sat, 21 Dec 2013 14:53:04 +0000 Experimental IR and Raman spectra of solid acetazolamide have been analysed by computing the molecular structures and vibrational spectra of monomer and dimer forms and water clusters of acetazolamide. The possible stable conformers of free acetazolamide molecule in the ground state were obtained by scanning the potential energy surface through the dihedral angles, D1 (1S-2C-6S-9N), D2 (4N-5C-12N-14C), and D3 (5C-12N-14C-16C). The final geometry parameters for the obtained stable conformers were determined by means of geometry optimization, carried out at DFT/B3LYP/6-31G++(d,p) theory level. Afterwards the possible dimer forms of the molecule and acetazolamide-H2O clusters were formed and their energetically preferred conformations were investigated using the same method and the same level of theory. The effect of BSSE on the structure and energy of acetazolamide dimer has been investigated. The assignment of the vibrational modes was performed based on the potential energy distribution of the vibrational modes, calculated by using GAR2PED program. The experimental vibrational wavenumbers of solid acetazolamide are found to be in better agreement with the calculated wavenumbers of dimer form of acetazolamide than those of its monomeric form. NBO analysis has been performed on both monomer and dimer geometries. Aysen E. Ozel, Serda Kecel Gunduz, Sefa Celik, and Sevim Akyuz Copyright © 2013 Aysen E. Ozel et al. All rights reserved. Terahertz Time Domain, Raman and Fourier Transform Infrared Spectroscopy of Acrylamide, and the Application of Density Functional Theory Thu, 19 Dec 2013 08:56:48 +0000 We present terahertz time domain spectra of acrylamide in the frequency range from 0.2 to 2 THz with nearly constant refractive index having an average value of 1.33 and an absorption coefficient. Raman (95–3000 cm−1) and FTIR (450–4000 cm−1) spectra also show good agreement with density functional theory (DFT) B3LYP 6-311G++ (3df 3pd) calculations except C-H and N-H stretching frequencies even after scaling with scale factor of 0.9679. We use MOLVIB to rescale such frequencies to match experimental values. Ramzan Ullah, Salah Ud-Din Khan, Muhammad Aamir, and Rasheed Ullah Copyright © 2013 Ramzan Ullah et al. All rights reserved. The In Situ Polymerization and Characterization of PA6/LiCl Composites Wed, 18 Dec 2013 15:51:11 +0000 PA6/LiCl composites were synthesized by in situ anionic polymerization based on the interaction between the inorganic salts and PA6. Sodium hydroxide as initiator and N-acetylcaprolactam as activator were used in the preparation of PA6/LiCl composites with variety of LiCl content. X-ray diffraction (XRD) and differential scanning calorimeter (DSC) testing results showed that both of degree of crystallinity and melting temperature of the composites were decreased under the influence of LiCl. And the γ crystal phase proportion increased with increasing the LiCl content to appropriate amount. Dandan Sun, Jiang Li, Qinghua Pan, Chaowei Hao, and Guoqiao Lai Copyright © 2013 Dandan Sun et al. All rights reserved. A Promising Material by Using Residue Waste from Bisphenol A Manufacturing to Prepare Fluid-Loss-Control Additive in Oil Well Drilling Fluid Wed, 11 Dec 2013 15:34:19 +0000 The residues mixture from Bisphenol A manufacturing process was analyzed. Fourier transform infrared (FTIR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance (NMR) were used to characterize the residues. The results indicated that the residues were complex mixture of several molecules. 3-(2-Hydroxyphenyl)-1,1,3-trimethyl-2,3-dihydro-1H-inden-5-ol and phenol were the main components of the residues. The technical feasibility of using it as phenol replacement in fluid-loss-control additive production was also investigated. The fluid-loss-control capacity of the novel additive was systematically investigated. It was discovered that the well fluid-loss performance of the prepared additive can be achieved, especially at high temperature. Zhi-Lei Zhang, Feng-Shan Zhou, Yi-He Zhang, Hong-Wei Huang, Ji-Wu Shang, Li Yu, Hong-Zhen Wang, and Wang-Shu Tong Copyright © 2013 Zhi-Lei Zhang et al. All rights reserved. Analysis of a Benzamide/Cholesterol Mixture by Using TLC/FTIR Technique Tue, 10 Dec 2013 09:14:13 +0000 We applied TLC/FTIR coupled with a mapping technique to analyze a cholesterol/benzamide mixture. Narrow-band TLC plates by using AgI as a stationary phase were used to separate benzamide and cholesterol. The distribution of cholesterol and benzamide spots was manifested by 3D chromatogram. Benzamide and cholesterol can be successfully separated by the narrow-band TLC plate. Moreover, characteristic bands of benzamide and cholesterol can be identified from their FTIR spectra. In addition, the FTIR spectra of the separated benzamide and cholesterol spots on the narrow band TLC plate are roughly the same as the corresponding reference IR spectra. Xiaokun Fan, Ran Guo, Jia-jia Shi, Haijun Wu, Anqi He, Yongju Wei, Cuige Liu, Shifu Weng, Zhanlan Yang, Yizhuang Xu, Isao Noda, and Jinguang Wu Copyright © 2013 Xiaokun Fan et al. All rights reserved. Fluorescent Properties of Hymecromone and Fluorimetric Analysis of Hymecromone in Compound Dantong Capsule Wed, 04 Dec 2013 17:41:47 +0000 Fluorescence spectra of hymecromone (4MU) aqueous solutions are investigated at different pHs. Two fluorescent species of 4MU, neutral molecular form and anion form, are considered to be the main fluorescent forms. Quantum yields of the two forms are measured to be 0.74 at pH 5.98 and 0.95 at pH 9.75, respectively. The ionization constant of 7-hydroxyl proton of 4MU is determined to be by a pH-fluorescence method. Addition of methanol into 4MU aqueous solution leads to a blue shift of maximum emission wavelength from 445 nm to 380 nm, and a decrease in fluorescence intensity. 3D fluorescence spectra of Chinese patent drug Compound Dantong Capsule (CDC) and its four component herbal drugs are also investigated. Based on their fluorescent properties, a novel fluorimetric method is proposed for the selective determination of 4MU in CDC without preseparation. The new method is suitable for the routine quality evaluation of CDC. Huanhuan Zhi, Jingdan Wang, Shujing Wang, and Yongju Wei Copyright © 2013 Huanhuan Zhi et al. All rights reserved. Preparation and Characterization of Lanthanum Carbonate Octahydrate for the Treatment of Hyperphosphatemia Wed, 04 Dec 2013 14:39:22 +0000 We proposed a new approach to prepare lanthanum carbonate via reactions between lanthanum chloride and NaHCO3. In the reaction, small amount of NaHCO3 solution was firstly added to the acidic lanthanum chloride solution to generate lanthanum carbonate nuclei and then NaHCO3 is added to the lanthanum chloride at a constant speed. This approach makes both precipitation reaction and neutralization reaction take place simultaneously. Consequently, lanthanum carbonate is produced at low pH environment (pH below 4.0) so that the risk of generating lanthanum carbonate hydroxide is reduced. The product of the above reaction is validated by EDTA titration, elemental analysis, and XRD characterization. In addition, we established a FTIR spectroscopic method to identify La(OH)CO3 from La2(CO3)2·8H2O. Lanthanum carbonate exhibits considerable ability to bind phosphate. Anqi He, Fengshan Zhou, Fang Ye, Ying Zhang, Xiren He, Xin Zhang, Ran Guo, Xing Zhao, Yan Sun, Ming Huang, Qin Li, Zhanlan Yang, Yizhuang Xu, and Jinguang Wu Copyright © 2013 Anqi He et al. All rights reserved. Spectroscopic and Gas Chromatographic Studies of Pigments and Binders in Gdańsk Paintings of the 17th Century Tue, 03 Dec 2013 11:26:54 +0000 This work presents spectroscopic (optical microscopy, OM; micro-Raman, Raman; and Fourier-transform adsorption infrared, FT-IR) and gas chromatographic studies of two famous panel paintings from the Gdańsk artists of the 17th century Golden Age, “Servilius Appius” by Isaac van den Blocke and “Allegory of Wealth” probably by Anton Möller. Application of the aforementioned methods allowed us to identify pigments and binders used in the panel paintings. In particular, it was determined that the yellow pigment used by both artists is lead-tin yellow type I (2PbO·SnO2), the white pigment is lead (II) carbonate hydroxide (2PbCO3Pb(OH)2), and the ground layer material consist of chalk (CaCO3). The analysis showed also that in the case of “Allegory of Wealth,” the red layer consists not only of cinnabar (HgS) but also of lead-tin yellow type I. Justyna Olszewska-Świetlik, Bożena Szmelter-Fausek, Ewa Pięta, and Edyta Proniewicz Copyright © 2013 Justyna Olszewska-Świetlik et al. All rights reserved. Improved Extended Multiplicative Scatter Correction Algorithm Applied in Blood Glucose Noninvasive Measurement with FT-IR Spectroscopy Mon, 02 Dec 2013 18:37:16 +0000 In order to improve the predictive accuracy of human blood glucose quantitative analysis model with fourier transform infrared (FT-IR) spectroscopy, this paper uses a method named improved extended multiplicative scatter correction (Im-EMSC), which can effectively eliminate the scattering effects caused by human body strong scattering. The principal components of the differential spectra are used instead of the pure spectra of the analytes in this algorithm. Calibrate the unwanted physical characteristic through the shape of the curve of principal components, and extract the original glucose concentration information. Im-EMSC can efficiently remove most of the pathlength difference and baseline shift influences. Firstly, Im-EMSC is used as a preprocessing method, and then partial least squares (PLS) regression method is adopted to establish a quantitative analysis model. In this paper, the result of Im-EMSC is compared with those popular scattering correction algorithms of multiplicative scatter correction (MSC) and extended multiplicative scatter correction (EMSC) preprocessing methods. Experimental results show that the prediction accuracy has been greatly improved with Im-EMSC method, which is helpful for human noninvasive glucose concentration detection technology. Qingbo Li, Qishuo Gao, and Guangjun Zhang Copyright © 2013 Qingbo Li et al. All rights reserved. Effect of Nitric Acid on the Low Fluorescing Performance of Drilling Fluid Lubricant Based Animal and Vegetable Oils Mon, 02 Dec 2013 18:33:51 +0000 After synthesis of mixed fatty acid triethanolamine ester surfactant based on animal and vegetable mixed oils, the reaction solution was added into 4% (wt/wt) liquid nitric acid or 9% (wt/wt) solid nitric acid as eliminating fluorescent agent continuing to react from 1 to 2 hours. The low fluorescence lubricant named E167 for drilling fluid was prepared, in which maximum fluorescence intensity () was less than 10 in three-dimensional fluorescence spectra of excitation wavelength range. When the E167 was added into fresh water based drilling fluid at the dosage of 0.5% (wt/wt), the sticking coefficient reduced rate () is 78% and the extreme pressure (E-P) friction coefficient reduced rate () is 79%. In the case of 4% brine mud with 0.5% (wt/wt) E167 in it, the and are 75% and 62%, respectively. After the hot rolling ageing test 180°C × 16 h with the E167 was added into fresh water based drilling fluid at the dosage of 1% (wt/wt), the and are greater than 70%, which shows a much better lubrication properties of strong resistance to high temperature. The fresh water based drilling fluid which contains 1% (wt/wt) E167 is almost nonfoaming even after hot rolling ageing 120°C × 16 h. Feng-shan Zhou, Zheng-qiang Xiong, Bao-lin Cui, Feng-bao Liu, Guang-huan Li, Jin-ran Wei, and Hua Cui Copyright © 2013 Feng-shan Zhou et al. All rights reserved. Interglobular Diffusion of an Energy Donor in Triplet-Triplet Energy Transfer in Proteins Sat, 02 Nov 2013 14:28:57 +0000 The triplet-triplet energy transfer between polar molecules of luminescent probe (eosin) as an energy donor and nonpolar molecules of energy acceptor (anthracene) is studied. Both the donor and the acceptor are bound to human serum albumin by noncovalent bonds. A dependence of rate constant of triplet-triplet energy transfer on human serum albumin concentration is revealed. A rate constant of eosin output from protein globules is determined. It is shown that the energy transfer occurs as a result of interglobular diffusion of eosin. The obtained results indicate that a protein-luminescent probe based sensor can be used for testing a concentration of polycyclic aromatic hydrocarbons in proteins. Andrey G. Melnikov, Alexander B. Pravdin, Vyacheslav I. Kochubey, Anna V. Kuptsova, and Gennady V. Melnikov Copyright © 2013 Andrey G. Melnikov et al. All rights reserved.