Quality Control of Tramadol in Kisangani: Development, Validation, and Application of a UV-Vis Spectroscopic Method

Context: Substandard and falsified medicines are circulating in low-income countries mostly without any control. We availed a simple and not expensive UV-Vis spectroscopic method to evaluate the quality of tramadol in Kisangani before and during the Covid-19 period. Methods: For the analytical quantitative method, an experimental design was applied to set up the optimal levels of the selected factors, namely, pH of dissolution medium, type of cuvette, and wavelength. Taking into account the capsule pharmaceutical formulation within 80 - 120 μg·mL-1 concentration range, we analyzed 89 tramadol samples from pharmacies and hospitals of the six Kisangani municipalities. Results: pH showed a significant effect on absorbance, whereas quartz cuvette and wavelength did not. A typical 100 μg·mL-1 tramadol solution gave an absorbance of 0.64 at 272 nm. Validation highlighted a matrix effect observed with a 6% bias. A correction factor of 0.9372 allowed to improve the accuracy profile, which were then totally included within the 10% acceptance limits. Quality control revealed that 25 samples out of 89 were not compliant in terms of manufacturing license, registration status in DRC and content as well. Conclusion: This study showed that the strengthening of analytical strategy in Kisangani is a need.

Application of Two-Dimensional Correlation UV-Vis Spectroscopy in Chinese Liquor Moutai Discrimination

Chinese liquor Moutai is the “National alcoholic drink” in China and plays a very important role of social activities in Chinese people’s life. In pursuit of high profits, some illegal counterfeit Moutai liquors have begun to appear in the market. Therefore, it is an urgent need for new techniques to discriminate the genuine and counterfeit Moutai liquor. In this work, the conventional Ultraviolet-Visible (UV-Vis) spectroscopy and two-dimensional correlation UV-Vis spectroscopy are applied to obtain the UV-Vis characteristic of Moutai liquor and counterfeit one, respectively. The experimental results reveal that the conventional UV-Vis spectra of the genuine and counterfeit Moutai liquor are similar. However, the two-dimensional correlation UV-Vis spectra of them are different and this method would be applied to differentiate the counterfeit Moutai liquor from the genuine Moutai liquor. Compared with conventional methods, this novel method has the advantages of easy operation, simple instrumentation and direct recognition, which make it a potential tool in the fields of food safety.

Sensitivity Enhancement in Uranium Determination by UV-Visible Spectroscopy Using Ion Imprinted Polymer

There is need to determination of uranium concentration at ppb level in environmental matrices.Due to low sensitivity of FAAS,UV-Visible Spectroscopy is generally used as measurement technique.In this study,ion-imprinted polymers(IIP)were prepared for uranyl ion(imprint ion)by formation of ternary(salicylaldoxime and 4-vinylpyridine)complex in 2-methoxy ethanol(porogen)following copolymerization with methacrylic acid(MAA)as a functional monomer and ethylene glycol dimethacrylate(EGDMA)as crosslinking monomer using 2,2-azobisisobutyronitrile as initiator.The synthesized polymers were characterized by FTIR and TGA analysis.ArsenazoⅢin 3M HClO_4 was used as complexing agent in the measurement step.The optimal pH for preconcentration was found to be between 3.5~6.5values.The developed method was applied to uranium(Ⅵ)determination in natural water samples.

UV-Vis Spectroscopy Study on Interaction between Microperoxidase-11 and Pr Ion Under Acid Rain Stress

Interaction between rare earth ion praseodymium (Pr(Ⅲ)) and MP11 with/without hydrogen ion (H +) in different media( aqueous, phosphate buffer, physiological condition) were studied by UV Vis spectroscopy. All the results indicate that Pr(Ⅲ) interacts with MP11, increasing the non planarity of porphyrin periphery, leading MP11 to form two conformations when titrated by Pr(Ⅲ). Excessive Pr(Ⅲ) acts as a contaminant in living organism. H + and Pr(Ⅲ) have antagonistic effect on MP11, suggesting that at suitable concentration under physiological conditions, Pr(Ⅲ) can be used as biomodulator in protecting plants from acid rain stress or in rehabilitating the harm.

Raman and UV-Vis Spectroscopy Applied to the Analysis of Liver Tissues from Rats with Myocardial Ischemia Induced by Isoproterenol

The application of the laser Raman spectroscopic（LRS） technique for the analysis of liver tissues from rats with myocardial ischemia induced by isoproterenol（ISO） was described.Animal model of myocardial ischemia was established for rats induced by ISO.Rats were randomly divided into four groups as normal group and myocardial ischemia groups.We observed the successful myocardial ischemia model via serum enzymes levels and hematoxylin-eosin（HE） staining,and detected the liver tissue of the rats from normal group and liver tissue of the rats from myocardial ischemia groups via UV-Vis spectroscopy（UV-Vis） and LRS,and the changes of the absorbance spectra were compared in the above four different groups.The results show that ISO can induce rat myocardial ischemia successfully.The spectrum of normal liver tissue supernatant exhibits a strong absorption band at 968 nm,but no absorption band appears in the spectra of liver tissue supernatant solutions from the rats with myocardial ischemia induction after 2,12 and 72 h presented at 968 nm.LRS results show that Raman intensities of the precipitates suffered from ISO-treatment after 2,12 and 72 h were obviously increased compared with that of the precipitate of the liver tissue of the normal rats suffered from 0.9 g/L normal saline（NS） treatment.These results indicate that LRS and UV-Vis can be harmless,nondestructive,rapid and effective methods for analyzing different pathological specimens of liver tissue from myocardial ischemia rats.

Electrocatalytic Oxidation of Hypophosphite on Nickel Electrode ──In Situ UV-Vis Spectroscopic study

The electrocatalytic oxidation of hypophosphite on a nickel electrode has been studiedby means of in site UV-Vis subtractive reflectance spectroscopy. An absorbency band around 245um . which was ascribed to the formation of an intermediate, PHO2-, was observed in theelectrocatalytic oxidation process. Accordingly, the electrocatalytic oxidation of hypophosphitemight undergo a H abstraction of hypophosphite from the P-H bond to form the phosphoruscentred radical PHO2-, which is subsequently electrooxidized to the final product, phosphite.

UV-Vis-SWNIR漫反射光谱结合偏最小二乘法测定蕨菜总多糖含量

目的建立UV-Vis-SWNIR漫反射光谱结合偏最小二乘法测定蕨菜中总多糖的含量。方法收集140批样品,从中随机选取20份作为完全外部验证集样品,用于验证模型的可靠性和准确性;其余80批样品为校正集,40批样品为检验集,用于筛选蕨菜总多糖的定量模型光谱预处理方法、主因子数、UV-Vis-SWNIR光谱特征波长。结果采用一阶导数法对原始光谱预处理,主因子数为7,结合随机青蛙算法筛选建模波长为925~1084、890~910、560~820、525~540、451~520、385~445、251~270 nm时,所得预测模型校正集R^(2)值为0.9617,RMSEC值为0.167%,检验集R^(2)值为0.9332,RMSEP值为0.208%,完全外部验证误差范围为-0.741%~0.853%。结论该方法快速可行,可用于蕨菜总多糖含量的预测。

Estimating Aluminum Leaching into Meat Baked with Aluminum Foil Using Gravimetric and UV-Vis Spectrophotometric Method

Baking meat by wrapping them in Aluminum (Al) foil is common in many countries. The excessive use of Al foil in baking and the disagreement about using Al foils were the motivation to do this study especially after the 2007 WHO/FDA Report. In this investigation, a gravimetric and a UV-Vis spectrophotometric method are used to estimate Aluminum (Al) leaching into meat baked by wrapping in Al foil. Three kinds of meat were used fish, cow stakes and chicken. The importance of Al exposure area was neglected by many studies. Five factors affecting Al leaching into meat are studied (baking temperature, baking time, additives, Al exposure area and weight of meat). The effect of cooking times (20, 40, 60 minutes) at 180℃ and cooking temperatures (160℃, 180℃, 200℃) at 60 minutes on the amount of Al leaching were evaluated. It was found that Al leaching into meat increased with increasing temperature, baking time, additives and Al exposure area. Moreover, Al exposure area was more effective than the weight of the meat. The Al leaching was highest in fish and lowest in chicken. Comparing the present results with the Provisional Tolerance Weekly Intake of Al approved by WHO/FDA, it shows that Al leaching into meat baked by wrapping in Al foil may add considerable doses into the diet. Continuous monitoring of Al foil used for baking meat is recommended.

Effect of Temperature on Optical Properties of Vegetable Oils Using UV-Vis and Laser Fluorescence Spectroscopy

UV-Vis absorption and fluorescence spectroscopy are used to test the quality and changes in the composition of extra virgin olive oil (EVOO) and canola oil (CO) with temperature. The increase of temperature caused a change in the molecular structures of both types of oils seen as a gradual decrease of intensity amplitudes of absorption and fluorescence signals. A significant alteration occurred at ≈200&#176C where almost the main spectra of pheophytin-a, b, carotenoids, lutein and vitamin E in EVOO and linoleic acid and oleic acid in CO disappeared. An independent experiment showed the output of laser changes linearly with the input in oil at constant temperature (i.e., room temperature) where the transmission values of ≈33% and ≈75% are determined for EVOO and CO respectively. However, the transmission through a heated oil exhibited a non-linear behaviour which indicates the molecular optical response to thermal changes. The effect of storage time and adulteration of oils were also evaluated.

In-situ UV-Vis Spectroscopy of Trisulfur Radicals in Lithium-Sulfur Batteries

Here we employ in-situ UV-Vis spectroscopy to monitor the sulfur redox reaction with oxygen-containing molecules as an additive,for example,biphenyl-4,4′-dicarboxylic acid(BDC).Furthermore,Raman spectrum,electron paramagnetic resonance(EPR),and electrospray ionization-mass spectrometry(ESI-MS)measurements reveal that the formation of BDC-S_(3)•^(‒)complexes can establish the long-term stability of polysulfide radicals,change the kinetics of sulfur redox reaction,and then generate decent capacity retention and rate capability.According to the density functional theory(DFT)analysis,S_(3)•^(‒)radicals are the underlying product of S_(6)^(2‒)cleavage,owing to the decreased chemical energy and the increased stability of S_(3)•^(‒)radicals through Lewis acid-base interaction.The assembled Li-S batteries with BDC additive deliver a high reversible capacity of 420 mA·h·g^(−1)over 200 cycles with over 98%Coulombic efficiency,under the current density of 0.2 C.

Terahertz Time-Domain Spectroscopy method for optical parameter extraction of plastic materials

A method for extracting optical parameters of plastics materials based on terahertz time domain spectroscopy is presented. The transmission-type Terahertz Time-Domain Spectroscopy(THz TDS) system is adopted to detect the refractive index and extinction coefficient on different plastic materials. Then the corresponding spectral information is obtained by Fourier transform of the terahertz time domain waveform of the sampling points, including the corresponding amplitude and phase information of the waveform. The optical parameter extraction model is built. By using the simplex optimization method, the curves of the refractive index and extinction coefficient for the plastic material are obtained. The experimental samples are made of different plastic parallel plate materials. The experimental results show that the optimization of optical parameters can improve their extraction accuracy, and the error of refractive index is ±0.005. Extraction technology with the simplex optimization method of optical parameter based on THz TDS can help to extract the optical parameters of engineering plastics. It is of great significance for the research of terahertz nondestructive testing.

Identification and analysis of serum samples by surface-enhanced Raman spectroscopy combined with characteristic ratio method and PCA for gastric cancer detection

This study aimed to explore the application of surface-enhanced Raman scattering(SERS)in the rapid diagnosis of gastric cancer.The SERS spectra of 68 serum samples from gastric cancer patients and healthy volunteers were acquired.The characteristic ratio method(CRM)and principal component analysis(PCA)were used to differentiate gastric cancer serum from normal serum.Compared with healthy volunteers,the serum SERS intensity of gastric cancer patients was relatively high at 722 cm^(-1),while it was relatively low at 588,644,861,1008,1235,1397,1445 and 1586 cm^(-1).These results indicated that the relative content of nucleic acids in the serum of gastric cancer patients rises while the relative content of amino acids and carbohydrates decreases.In PCA,the sensitivity and specificity of discriminating gastric cancer were 94.1%and 94.1%,respectively,with the accuracy of 94.1%.Based on the intensity ratios of four characteristic peaks at 722,861,1008 and 1397 cm^(-1),CRM presented the diagnostic sensitivity and specificity of 100%and 97.4%,respectively,and the accuracy of 98.5%.Therefore,the three peak intensity ratios of I_(722)/I_(861),I_(722)/I_(1008)and I_(722)/I_(1397)can be considered as biologicalfingerprint information for gastric cancer diagnosis and can rapidly and directly reflect the physiological and pathological changes associated with gastric cancer development.This study provides an important basis and standards for the early diagnosis of gastric cancer.

Comparison of Calibration Curve Method and Partial Least Square Method in the Laser Induced Breakdown Spectroscopy Quantitative Analysis

The Laser Induced Breakdown Spectroscopy (LIBS) is a fast, non-contact, no sample preparation analytic technology;it is very suitable for on-line analysis of alloy composition. In the copper smelting industry, analysis and control of the copper alloy concentration affect the quality of the products greatly, so LIBS is an efficient quantitative analysis tech- nology in the copper smelting industry. But for the lead brass, the components of Pb, Al and Ni elements are very low and the atomic emission lines are easily submerged under copper complex characteristic spectral lines because of the matrix effects. So it is difficult to get the online quantitative result of these important elements. In this paper, both the partial least squares (PLS) method and the calibration curve (CC) method are used to quantitatively analyze the laser induced breakdown spectroscopy data which is obtained from the standard lead brass alloy samples. Both the major and trace elements were quantitatively analyzed. By comparing the two results of the different calibration method, some useful results were obtained: both for major and trace elements, the PLS method was better than the CC method in quantitative analysis. And the regression coefficient of PLS method is compared with the original spectral data with background interference to explain the advantage of the PLS method in the LIBS quantitative analysis. Results proved that the PLS method used in laser induced breakdown spectroscopy was suitable for simultaneous quantitative analysis of different content elements in copper smelting industry.

Photon energy response optimization using few-channel spectroscopy dose method for Si-PIN photodetector applied in personal dose equivalent measurements

Si-PIN photodetectors having features such as low cost,small size,low weight,low voltage,and low power consumption are widely used as radiation detectors in electronic personal dosimeters(EPDs).The technical parameters of EPDs based on the Si-PIN photodetectors include photon energy response(PER),angular response,inherent error,and dose rate linearity.Among them,PER is a key parameter for evaluation of EPD measurement accuracy.At present,owing to the limitations of volume,power consumption,and EPD cost,the PER is usually corrected by a combination of single-channel counting techniques and filtering material methods.However,the above-mentioned methods have problems such as poor PER and low measurement accuracy.To solve such problems,in this study,a 1024-channel spectrometry system using a Si-PIN photodetector was developed and fullspectrum measurement in the reference radiation fields was conducted for radiation protection.The measurement results using the few-channel spectroscopy dose method showed that the PER could be controlled within±14%and±2%under the conditions of two and three energy intervals,respectively,with different channel numbers.The PER measured at 0°angle of radiation incidence meets the-29%to+67%requirements of IEC 61526:2010.Meanwhile,the channel number and counts-to-dose conversion factors formed in the experiment can be integrated into an EPD.

Highly Effective Detection of Amitraz in Honey by Using Surface-Enhanced Raman Scattering Spectroscopy Coupled with Chemometric Methods

As an effective and universal acaricide, amitraz is widely used on beehives against varroasis caused by the mite Varroa jacobsoni. Its residues in honey pose a great danger to human health. In this study, a sensitive, rapid, and environmentally friendly surface-enhanced Raman spectroscopy method (SERS) was developed for the determination of trace amount of amitraz in honey with the use of silver nanorod (AgNR) array substrate. The AgNR array substrate fabricated by an oblique angle deposition technique exhibited an excellent SERS activity with an enhancement factor of -10^7. Density function theory was employed to assign the characteristic peak of amitraz. The detection of amitraz was further explored and amitraz in honey at concentrations as low as 0.08 mg/kg can be identified. Specifically, partial least square regression analysis was employed to correlate the SERS spectra in full-wavelength with Camitraz to afford a multiple-quantitative amitraz predicting model. Preliminary results show that the predicted concentrations of amitraz in honey samples are in good agreement with their real concentrations. Compared with the conventional univariate quantitative model based on single peak’s intensity, the proposed multiple-quantitative predicting model integrates all the characteristic peaks of amitraz, thus offering an improved detecting accuracy and anti-interference ability.

Evaluation of gases'molecular abundance ratio by fiber-optic laser-induced breakdown spectroscopy with a metal-assisted method

A metal-assisted method is proposed for the evaluation of gases’molecular abundance ratio in fiber-optic laser-induced breakdown spectroscopy(FO-LIBS).This method can reduce the laser ablation energy and make gas composition identification possible.The principle comes from the collision between the detected gases and the plasma produced by the laser ablation of the metal substrate.The interparticle collision in the plasma plume leads to gas molecules dissociating and sparking,which can be used to determine the gas composition.The quantitative relationship between spectral line intensity and molecular abundance ratio was developed over a large molecular abundance ratio range.The influence of laser ablation energy and substrate material on gas quantitative calibration measurement is also analyzed.The proposed metal-assisted method makes the measurement of gases’molecular abundance ratios possible with an FO-LIBS system.

紫外-可见(UV-Vis)光谱法在中药质量控制中的应用

紫外-可见(UV-Vis)光谱法作为一种传统的光谱分析方法,在中药质量控制领域得到广泛应用,本文对该技术的应用现状进行文献综述,对该技术在大类物质含量测定、作为色谱检测器、及其与化学计量学的结合使用情况进行详细论述,并对其应用前景进行展望,可为该技术更为深入、全面的应用提供参考。

A New Sample-Selection and Modeling Method Based on Near-Infrared Spectroscopy and Its Industrial Application

Near-infrared( NIR) spectroscopy has been widely employed as a process analytical tool( PAT) in various fields; the most important reason for the use of this method is its ability to record spectra in real time to capture process properties. In quantitative online applications,the robustness of the established NIR model is often deteriorated by process condition variations,nonlinear of the properties or the high-dimensional of the NIR data set. To cope with such situation,a novel method based on principal component analysis( PCA) and artificial neural network( ANN) is proposed and a new sample-selection method is mentioned. The advantage of the presented approach is that it can select proper calibration samples and establish robust model effectively. The performance of the method was tested on a spectroscopic data set from a refinery process. Compared with traditional partial leastsquares( PLS),principal component regression( PCR) and several other modeling methods, the proposed approach was found to achieve good accuracy in the prediction of gasoline properties. An application of the proposed method is also reported.

Augev Method and an Innovative Use of Vocal Spectroscopy in Evaluating and Monitoring the Rehabilitation Path of Subjects Showing Severe Communication Pathologies

A strongly connotative element of developmental disorders (DS) is the total or partial impairment of verbal communication and, more generally, of social interaction. The method of Vocal-verb self-management (Augev) is a systemic organicistic method able to intervene in problems regarding verbal, spoken and written language development successfully. This study intends to demonstrate that it is possible to objectify these progresses through a spectrographic examination of vocal signals, which detects voice phonetic-acoustic parameters. This survey allows an objective evaluation of how effective an educational-rehabilitation intervention is. This study was performed on a population of 40 subjects (34 males and 6 females) diagnosed with developmental disorders (DS), specifically with a diagnosis of the autism spectrum disorders according to the DSM-5. The 40 subjects were treated in “la Comunicazione” centers, whose headquarters are near Bari, Brindisi and Rome. The results demonstrate a statistical significance in a correlation among the observed variables: supervisory status, attention, general dynamic coordination, understanding and execution of orders, performing simple unshielded rhythmic beats, word rhythm, oral praxies, phono-articulatory praxies, pronunciation of vowels, execution of graphemes, visual perception, acoustic perception, proprioceptive sensitivity, selective attention, short-term memory, segmental coordination, performance of simple rhythmic beatings, word rhythm, voice setting, intonation of sounds within a fifth, vowel pronunciation, consonant pronunciation, graphematic decoding, syllabic decoding, pronunciation of caudate syllables, coding of final syllable consonant, lexical decoding, phoneme-grapheme conversion, homographic grapheme decoding, homogeneous grapheme decoding, graphic stroke.

Assessment of Nutrients of Escamoles Ant Eggs Limotepum apiculatum M. by Spectroscopy Methods

Edible insects, escamoles ant eggs of the Formicidae family are consumed by cultural tradition at rural communities and by sensory characteristics at high class restaurants of Mexico; however, people ignore the importance of insect consumption in the nutrition of humans. Laboratory spectroscopy methods in food analysis represent benefits in time and precision. The aim of this study is to assess macronutrients and micronutrients of escamoles and eggs by spectroscopic methods to inform population the benefits they provide in health and to mention the advantage in the use of these techniques at laboratory work. Samples were gather the second week of March and April 2012, at Hidalgo State and analyze moisture and macronutrients by AOAC （Association of Official Analytical Chemistry） methods, amino acids by cation exchange chromatography, tryptophan was determined by a colorimeter method, fatty acids by GC （gas chromatography） using helium as a carrier （AOAC）, fat soluble vitamins A, D and E by HPLC （high performance liquid chromatography）, and minerals by atomic absorption spectrophotometers and phosphorus by colorimeter （AOAC）. Data showed high amount in proteins, lipids and minerals; low in fiber and soluble carbohydrates; contained all essential amino acids. Fatty acids contain monounsaturated and polyunsaturated. Fat soluble vitamins A, D and E. Minerals： sodium, phosphorus, potassium, magnesium, calcium and manganese. Escamoles ant eggs include polyunsaturated fatty acids essential for mental development, vitamin A to prevent eye diseases, vitamin E as antioxidant and vitamin D involved in calcium absorption that low intake, impair grow and bone health. Iron and zinc contained anemia. Regarding the laboratory benefits, needs less expensive chemicals, testing is clean, rapid and easy results of multiple samples, but it is required to handle by qualified chemists. In conclusion, data may change according to biotic and abiotic conditions of the environment; however, escamoles have all nutrients in adequate balance to improve human health; and provide faster and precise results.