Quartz Cell Research Articles

Design of Mechanical Multi-Sensor for Contaminated Water Filter Applications

Effect of addition (salts, soil and bacteria) on piezoelectric detecting a signal of a specific liquid like water has been inspected here in the project. Identifying signals (piezoelectric) categorized and accomplished by usage of transducer that conducts a mechanical signal in the direction of the water liquid cell, and then the receptor collects the weakened indications. The quartz cell (contains water solution) embedded between the two piezo crystals and piezo crystals with silver (Ag) nanowire thin film prepared using hydrothermal method. It is clear that the formation of the yield is rope-similar and close to be uniform in width (60 ± 10 nm) whereas the extent is in a moderately wide range (from 0.2 to 4 μm) with an average at 2.5 μm. Four peaks can be recognized in XRD results, it is clear according to the ASTM cards that the film is polycrystalline at which (111), (200) and (220) silver (Ag) respectively. The range of functioning frequencies was (400 kHz - 40MHz), for all specimens, the measurement outcomes that involved reporting the first order resonance frequencies. The data presented shifting the resonance frequency to the higher order frequency for addititive cases (salts+soil+bacteria) of water.

Novel Validated UV Spectroscopic Method for Routine Analysis of Decitabine Drug Substance

Abstract: Objectives: In the proposed study, a basic, novel, protected economic, delicate and cost-effective UV-Spectrophotometric technique for the analysis of Decitabine which is antineoplastic drug. Methods: The created method was approved according to ICH rules. The decitabine indicated maximum absorption at 221 nm. This strategy can successfully apply for estimation of Decitabine in active pharmaceutical ingredient (API) form for routine examination with UV identification at 221 nm. A Shimadzu UV-Visible spectrophotometer 1800 with 1 cm quartz cells and Acetonitrile (ACN) as diluent was utilized in this technique. Results: The Developed technique obeyed Beer's-Lambert's law in the conc. of 5.0-15.0 ug/ml, having R2 of 0.9993 and 99.82%±0.75 recovery of decitabine was found. Different approval parameters like linearity, accuracy, precision and robustness were performed and were found to be within the limits as per the guidelines of ICH. Key words: Decitabine, UV-spectroscopy, Validated method, ICH guidelines, Beer’s Lambert’s law, Analysis.

A thermostatic chamber for doppler-broadening thermometry of mercury vapors

We present an isothermal chamber designed and realized at the Italian Metrological Institute (INRiM) to stabilize the temperature of a quartz cell for Doppler-broadened precision spectroscopy of mercury atoms in the UV region for the practical realization of the new definition of kelvin. The challenge of this apparatus is the capability to control, with great accuracy, the temperature of a non-cylindrical quartz cavity containing the mercury vapors. The temperature was actively controlled and maintained stable within 0.05 mK at the triple point of water for 15 h, but longer periods are possible. The spatial uniformity was also characterized. The traceability of temperature measurements and the complete uncertainty budget are discussed.

A comparison of data quality using quartz vs. sapphire cell windows in analytical ultracentrifugation

Analytical ultracentrifugation (AUC) cells use either quartz or sapphire windows as end caps for the cell housing. Current generation sapphire windows are not recommended for absorbance data collection below 235nm, because the window material shows a precipitous drop in transmittance at low wavelengths due to impurities in the sapphire. Quartz windows can be used below 235nm as they do not exhibit adverse transmittance at low wavelengths. In this study, we demonstrate the optical properties of new generation sapphire windows and compare them to those of quartz windows across a wide range of wavelengths and present the results of sedimentation velocity experiments on BSA using both types of windows using data collected at both the 280nm absorbance maxima as well as the 230-240nm (closer to the peptide bond maximum). Our results show that the quartz and new generation sapphire windows deliver identical results in absorbance mode. We also demonstrate that quartz windows suffer significant mechanical deformation while spinning at very high speeds, while sapphire windows do not. This renders Rayleigh interference mode data collected at high speeds using quartz windows much noisier than with sapphire windows-which we have quantified by measuring how the signal to noise ratio of Fourier transformed Rayleigh interference scans degrades at high speed. Thus, we conclude that new-generation sapphire windows can be used for all AUC experiments through almost the entire mid UV range-obviating the need for quartz windows, unless wavelengths below 220nm must be accessed.

Role of Thermolysin in Catalytic-Controlled Self-Assembly of Fmoc-Dipeptides

In recent years, short peptide self-assembled materials, prepared under the control of the thermolysin catalyst, have been investigated extensively and shown to acquire various morphologies and fun...

A solid-phase fluorescent, quenching method for the determination of trace amounts of nitrite in foods with neutral red

A simple and sensitive solid-phase fluorescent quenching method for the determination of trace amounts of nitrite in food samples has been developed. The method is based on the reaction between nitrite and neutral red, which is used as an emission reagent, to form a non-fluorescent compound in 0.1 mol/L hydrochloric acid. The fluorescent intensity was measured in 5-mm quartz cells with excitation and emission wavelengths of 548 and 609 nm, respectively. The degree of fluorescent quenching showed good linearity at concentrations of nitrite between the ranges of 40-200 μg/L. The detection limit is 8.1 μg/L and the RSD is 1.7%. The general coexisting ions do not interfere with the reaction of neutral red with nitrite. The proposed method was applied to the determination of trace amounts of nitrite in food samples with satisfactory results. In addition, the mechanism involved in the reaction was discussed.

Chemical and photochemical stability studies on diloxanide furoate in carbohydrates and polyols solutions

The effects of aqueous solutions containing sucrose, glucose, fructose, lactose and sorbitol on the chemical stability of diloxanide furoate (DF) were investigated in acid and alkaline media at 40°C and room temperature (25°C ± 1, adjusted through thermostatically controlled central-cooling system). All above compounds accelerated the rate of hydrolysis of DF in alkaline medium at 40°C. At room temperature, different brands of sucrose and glucose had adverse effects on the stability of DF. On the other hand, DF was relatively stable in fructose, lactose and sorbitol, as well as in a commercially available Tang® preparation containing sugar, buffers, stabilizers and artificial colours. The optimum pH range of stability of DF in solutions containing these carbohydrates lies below pH 4.5. The influence of β-cyclodextrin (β-CD) and hydroxypropyl β-cyclodextrin (HP-β-CD) on the chemical and photochemical stability of DF was also investigated. Para-aminobenzoic acid (PABA), ascorbic acid and the Tang® preparation showed good photo-protective effect on DF solutions irradiated at 254 nm in quartz cell. The observed accelerated rate of hydrolysis of DF by carbohydrates in alkaline medium is proposed to be due to a nucleophilic reaction mechanism while the photostabilization of DF solutions in the presence of PABA, ascorbic acid and the Tang® preparation is proposed to be due to a spectral overlay effect. All above studies were conducted using a stability-indicating HPLC method.

Optofluidic Formaldehyde Sensing: Towards On-Chip Integration.

Formaldehyde (HCHO), a chemical compound used in the fabrication process of a broad range of household products, is present indoors as an airborne pollutant due to its high volatility caused by its low boiling point ( °C). Miniaturization of analytical systems towards palm-held devices has the potential to provide more efficient and more sensitive tools for real-time monitoring of this hazardous air pollutant. This work presents the initial steps and results of the prototyping process towards on-chip integration of HCHO sensing, based on the Hantzsch reaction coupled to the fluorescence optical sensing methodology. This challenge was divided into two individually addressed problems: (1) efficient airborne HCHO trapping into a microfluidic context and (2) 3,5–diacetyl-1,4-dihydrolutidine (DDL) molecular sensing in low interrogation volumes. Part (2) was addressed in this paper by proposing, fabricating, and testing a fluorescence detection system based on an ultra-low light Complementary metal-oxide-semiconductor (CMOS) image sensor. Two three-layer fluidic cell configurations (quartz–SU-8–quartz and silicon–SU-8–quartz) were tested, with both possessing a 3.5 µL interrogation volume. Finally, the CMOS-based fluorescence system proved the capability to detect an initial 10 µg/L formaldehyde concentration fully derivatized into DDL for both the quartz and silicon fluidic cells, but with a higher signal-to-noise ratio (SNR) for the silicon fluidic cell () when compared to the quartz fluidic cell (). The signal intensity enhancement in the silicon fluidic cell was mainly due to the silicon absorption coefficient at the excitation wavelength,, which is approximately five times higher than the absorption coefficient at the fluorescence emission wavelength, .

Cytotoxicity of fractured quartz on THP-1 human macrophages: role of the membranolytic activity of quartz and phagolysosome destabilization

The pathogenicity of quartz involves lysosomal alteration in alveolar macrophages. This event triggers the inflammatory cascade that may lead to quartz-induced silicosis and eventually lung cancer. Experiments with synthetic quartz crystals recently showed that quartz dust is cytotoxic only when the atomic order of the crystal surfaces is upset by fracturing. Cytotoxicity was not observed when quartz had as-grown, unfractured surfaces. These findings raised questions on the potential impact of quartz surfaces on the phagolysosomal membrane upon internalization of the particles by macrophages. To gain insights on the surface-induced cytotoxicity of quartz, as-grown and fractured quartz particles in respirable size differing only in surface properties related to fracturing were prepared and physico-chemically characterized. Synthetic quartz particles were compared to a well-known toxic commercial quartz dust. Membranolysis was assessed on red blood cells, and quartz uptake, cell viability and effects on lysosomes were assessed on human PMA-differentiated THP-1 macrophages, upon exposing cells to increasing concentrations of quartz particles (10–250 µg/ml). All quartz samples were internalized, but only fractured quartz elicited cytotoxicity and phagolysosomal alterations. These effects were blunted when uptake was suppressed by incubating macrophages with particles at 4 °C. Membranolysis, but not cytotoxicity, was quenched when fractured quartz was incubated with cells in protein-supplemented medium. We propose that, upon internalization, the phagolysosome environment rapidly removes serum proteins from the quartz surface, restoring quartz membranolytic activity in the phagolysosomes. Our findings indicate that the cytotoxic activity of fractured quartz is elicited by promoting phagolysosomal membrane alteration.

Simultaneous estimation of naltrexone and bupropion in pharmaceutical dosage form by using UV spectroscopy

A sensitive and validated method has been developed for simultaneous estimation of Naltrexone and Bupropion in pharmaceutical dosage form by using UV Spectroscopy, without prior separation, by four different techniques (Simultaneous Equation, Absorbance Ratio method, Dual Wavelength Method and Derivative Spectroscopic Method). The work was carried out on Shimadzu electron UV1800 double beam UV-Visible spectrophotometer. The absorption spectra of reference and test solutions were carried out in 1 cm matched quartz cell over the range of 200 - 400 nm. The linearity ranges for Naltrexone and Bupropion were 2-10 μg/ml. The results of the analysis have been validated statistically and by recovery studies. The proposed procedures are rapid, simple, require no preliminary separation steps and can be used for routine analysis of both drugs in quality control laboratories.

Quartz optical cells with alkali-metal vapour for aerospace

This work for the first time analyses the impact of cosmic radiation on quartz cells with rubidium vapour and buffer gas, as well as the ensuing change in stability of atomic frequency standards (AFS) relying on such cells. It is demonstrated that the main effect consists in variation of partial pressure of nitrogen, which is a part of the buffer gas mix. This leads to degraded AFS stability. It was established by modelling that this effect is not significant because material degradation of the AFS stability is only likely to happen over a long period of time, as long as several decades. It can be concluded on the basis of the proposed analysis that a gas cell with rubidium vapour and buffer gas is the most reliable element of a satellite-borne AFS and that it is less affected by exposure to ionising radiation than electronic components of AFS.

Second-derivative spectrophotometry for the analysis of simvastatin in polymeric nanocapsules

Conventional spectrophotometry methods are very susceptible to the presence of interferences in complex mixtures such as nanoparticules, requiring prior treatment or extraction of the analyte, and not always providing an adequate response. Derivative spectrophotometry method is capable to eliminate its interference; it is an alternative method for drugs determination in complex matrices. This work investigated the utility of derivate spectrophotometry in assay of simvastatin in polymeric nanocapsules (SIVNC). Shimadzu® UV-1650 double-beam spectrophotometer with 1.0 cm quartz cells was used in this study. The second-order deriva­tive spectrum was obtained employing Δλ=20,000 nm and scaling factor=9.0. The determinations were made at 239 nm (2D239) by zero-crossing method. 2D239 method was validated employing the parameters: specificity, linearity, robustness, precision and accuracy. Results: The specificity test showed there was no interference of constituents commonly found in SIVNC formulation in 2D239. The standard curve showed a correlation coefficient of 0.994. The robustness was evaluated by small changes in the conditions of sample analysis and however, no significant changes were observed regarding drug quantitation. The precision was demonstrated by relative standard deviation (RSD) of intra-day (RSD=1.61-3.76) and inter-day studies (RSD=2.32). The recovery test resulted in an average of 100.66%, which confirmed the accuracy of the method. The procedure was simple and rapid; therefore this technique offers an alternative for determination of SIVNC without interferences.

Change of phase from ?-Bi2O3 to ?-Bi2O3 using the ceramic microwave-assisted approach and its increase of capacitance

The use of microwaves for the synthesis of materials is very important due to its versatility, it is an economical option, friendly with the environment, generates a low energy demand and the syntheses are carried out in very short times. There are many methods that use microwaves to obtain materials, however, the simplest one is the ceramic method, which consists in blending by grinding the reagents or precursors, which are placed in a quartz cell and finally carried to the microwave oven for synthesis. The reagents used to carry out this research are ?-Bi2O3 and graphite. The phase change in the ?-Bi2O3 was obtained despite the differences in weight composition and the variation of power level and irradiation time inside the microwave oven. X-ray diffraction and scanning electron microscopy were used to verify the phase and morphology of the samples before and after irradiation. The last step of this work was the capacitance measurement of the composites made of 0.39 g of alumina and 0.01 g of the product of graphite and bismuth oxide after irradiation at different conditions. The results demonstrated an increasing of capacitance in all the samples conformed by ?-Bi2O3/C/Al2O3.

ВИЗНАЧЕННЯ КЕТОПРОФЕНУ І ЦЕФТІОФУРУ У ВЕТЕРИНАРНИХ ПРЕПАРАТАХ СПЕКТРОФОТОМЕТРИЧНИМ МЕТОДОМ

Мета роботи. Розробка методики визначення кетопрофену та цефтіофуру в комбінованих ветеринарних препаратах спектрофотометричним методом.
 Матеріали і методи. Ветеринарні препарати «Процефен-100» і «Коцефен-200» (ТОВ «Ветсинтез», Харків, Україна). У роботі використовували стандартні зразки кетопрофену та цефтіофуру і допоміжних речовин фармакопейної чистоти (Sigma-Aldrich). Спектрофотометричні (СФ) вимірювання проводили на скануючому спектрофотометрі CARY.WIN – UV-VIS-50 (Varian, США) у кварцових кюветах із товщиною поглинаючого шару l = 1 см.
 Результати й обговорення. Одночасно неможливо визначити цефтіофур та кетопрофен у комбінованих лікарських препаратах прямим спектрофото-метруванням. В електронних спектрах поглинання їхніх модельних сумішей спостерігається перекривання максимумів визначуваних речовин. Експериментально підібрані умови їхнього розділення для наступного визначення прямим спектрофотометруванням. Оптимальним розчинником виявився дихлорметан, у якому кетопрофен розчиняється, тоді як цефтіофур залишається нерозчинним. Для розчинення цефтіофуру використовували етанол 96 %. Наявність допоміжних речовин не впливає на спектральні характеристики визначуваних речовин, що було показано при аналізі модельних сумішей препаратів із допоміжними речовинами та без них. Методика полягає у вилученні кетопрофену дихлорметаном і його прямому спектрофотометричному визначенні за довжини хвилі 254 нм, а також прямому спектрофотометричному визначенні цефтіофуру, вилученого етанолом, за довжини хвилі λ = 290 нм.
 Висновки. Встановлено умови розділення субстанцій кетопрофену та цефтіофуру, на основі чого розроблено методику розділення та кількісного спектрофотометричного визначення у двох комбінованих ветеринарних препаратах із різним співвідношенням визначуваних речовин. Розраховано метрологічні характеристики методики, а отримані результати кількісного визначення кетопрофену і цефтіофуру статистично не відрізняються від результатів отриманих заметодикою ВЕРХ (за F- та t-критеріями).

Characterization of Some Natural Oils Used for Medical Purposes by Ultraviolet – Visible spectroscopy

The significant role played by alternative medicine in recent years led us to carry out a simple spectral study of some natural oils used in medical applications. The study highlighted the form of visible – ultraviolet spectroscopy (uv-vis.) analysis as a non-destructive and fast technique in the determination of absorption spectrum of some natural oils which used for medical purposes. Three types of commercial medicinal natural oils namely; Castor, Camphor and Glycerol oils. Five cm3 from every kind of oil was placed in the quartz cell and exposed to radiation in uv and visible spectrum. The most significant value of the absorbance of Castor oil at the wavelength of 340 nm was about 3.2324%, the highest amount of the absorption spectrum is at a wavelength of 320nm and equal to 1.6574 %. The highest value of the absorption spectrum is at a wavelength of 380nm and equal to 0.0401%. The viscosity and density measurements were carried out for all samples.

Spectrophotometric Quantification of Anti-inflammatory Drugs by Application of Chromogenic Reagents.

Simple, specific, accurate, precise, sensitive, and cost effective spectrophotometric methods were developed and validated for quantification of the drugs lornoxicam (LOR) and mesalamine (MES) in pure form and in pharmaceutical formulations. A Shimadzu UV-1800 double-beam UV-Visible spectrophotometer having a spectral bandwidth of 0.1 nm with wavelength accuracy ±0.1 nm with a pair of 1 cm path length matched quartz cells was used to measure the absorbance of the resulting solution. Method I was used for the quantification of LOR, based on measurement of the absorbance of bluish green chromogen complex at 760 nm, which is formed by the reaction of LOR with ferric chloride and potassium ferricyanide (redox technique). Method II was used for the quantification of MES, based on measurement of the absorbance of yellow chromogen at 400 nm, which is formed by the condensation reaction of the primary amino group of MES with salicylaldehyde reagent (SA) (Schiff base formation). Both methods obeyed Beer's law in the concentration range of 0.5-4.5 μg/mL and 0.2-1.7 μg/mL with good correlation coefficients of 0.9974 and 0.998 for methods I and II, respectively. The developed method is simple, sensitive, and specific, which was validated statistically as per ICH guidelines, and can be used in the routine analysis of LOR and MES in pharmaceutical dosage forms.

A New Optical Method for Online Monitoring of the Light Dose and Dose Profile in Photodynamic Therapy.

Photodynamic therapy (PDT) has gained widespread popularity in the last decades because of its distinctive advantages over the other commonly used cancer treatments. PDT dosimetry is a crucial factor in achieving a good optimization of PDT treatment planning. PDT dosimetry is a complex task since light dose as well as photosensitizer and oxygen concentrations in tissue need to be measured (ideally continuously) to be able to fully characterize the biological response. Light dose in PDT is routinely measured by the optical fibers that provide dose data at a limited number of discrete points and are not able to capture spatial dose profiles. The objective of this study is to propose and develop a new optical method for online monitoring of the dose profile data for PDT. Using the digital holography technique, first, the general sketch of an experimental setup for PDT light dosimetry is provided. The theory behind the proposed method for using the experimental setup in PDT light dosimetry is fully described, and its limits of validity are determined. In a proof of principle study, the ability of the method for online monitoring of the absorbed light dose profile in PDT is evaluated by a simple experimental setup. The experimental results confirm the usefulness of the proposed method in providing continuous online dose profiles. The absorbed light dose profiles from an infrared light source in a quartz cell containing water are measured and shown. The depth-dose curves are extracted and it is shown that how these dosimetric data can be used for assisting the physicians in determining the appropriate spatiotemporal characteristics for treating the infected tissues and solid tumors with the required light dose amounts. A conversion relation is also derived for transforming the measured light dose with the proposed method to the most frequently used dose values by PDT practitioners, in terms of light power per square area. There is no restriction in using the method with other commonly used light sources in PDT, like light-emitting diodes and filtered lamps, with different wavelengths in visible or infrared regions of the spectrum. More complex experimental setups can be used in future studies to study the role of accumulated photosensitizers in malignant tissues. The proposed method in this study can also be used for light dose monitoring in other biomedical applications, where light is used for treating special diseases, and patients must receive sufficient amounts of light dose. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

High-precision measurement and ab initio calculation of the (6s26p2) 3P0→3P2 electric-quadrupole-transition amplitude in Pb208

We have completed a measurement of the $(6s^26p^2)\, ^3\!P_0 \rightarrow \, ^3\!P_2$ 939 nm electric quadrupole ($E2$) transition amplitude in atomic lead. Using a Faraday rotation spectroscopy technique and a sensitive polarimeter, we have measured this very weak $E2$ transition for the first time, and determined its amplitude to be $\langle ^3\!P_2 || Q || ^3\!P_0 \rangle$ = 8.91(9) a.u.. We also present an ab initio theoretical calculation of this matrix element, which agrees with experiment at the 0.5\% level. We heat a quartz vapor cell containing $^{208}$Pb to between 800 and 940 $^{\circ}$C, apply a $\sim \! 10 \, {\rm G}$ longitudinal magnetic field, and use polarization modulation/lock-in detection to measure optical rotation amplitudes of order 1 mrad with noise near 1 $\mu$rad. We compare the Faraday rotation amplitude of the $E2$ transition to that of the $^3\!P_0 -\, ^3\!P_1$ 1279 nm magnetic dipole ($M1$) transition under identical sample conditions.

Determination of N, N-diethyl-3-methylbenzamide and ethyl-butyl-acetylaminopropionate in insect repellent using near infrared spectroscopy and multivariate calibration

Aedes aegypti mosquitoes are vectors of diseases such as dengue, chikungunya, zika and yellow fever. With the increase in the incidence of these diseases the population has resorted to the use of repellents searching to protect themselves from mosquito attack. The Brazilian market offers a wide variety of products with different active principles in varying levels of concentration, times of action and different prices, where DEET (N, N-diethyl-3-methylbenzamide) and IR3535 (ethyl-butyl-acetylaminopropionate) based repellents are suitable for use around adults and children, respectively. The action time of these repellents depends, among other factors, on the concentration of their active ingredients. Chromatographic methods are recommended to quantify these compounds in different samples. However, these methods require long analysis time, and use reagents that are expensive and generate toxic waste. Near Infrared Spectroscopy (NIRS) has been applied in several areas of research on this subject and is characterized by its rapid, low cost, non-destructive characteristics no sample treatment is required. The present work proposes the development of a methodology based on NIR spectroscopy and multivariate calibration for determination of DEET and IR 3535 in samples from commercial repellents. A PerkinElmer FT-NIR spectrometer equipped with a 0.1 cm quartz cell was used to obtain the NIR spectra in the range of 750–2500 nm, with a resolution of 0.1 nm and an average of 16 scans. The reference analysis for the determination of DEET and IR3535 was performed using high performance liquid chromatography with diode array ultraviolet detection (HPLC-DAD). Calibration models based on partial least squares (PLS) regression across spectral bands, the same algorithm using intervals (iPLS), and multiple linear regression (MLR) with previous selected of variables by successive projections algorithm (SPA), stepwise (SW) and genetic algorithm (GA) were developed and compared. Satisfactory prediction results were obtained for all models with RMSEP values ranging from 0.70 to 1.18% (m m−1) and 0.64 to 1.12% (m m−1) for DEET and IR3535, respectively. In addition, no systematic error was observed and no significant differences were found between predicted and reference values obtained by HPLC analysis for 178 samples, according to a t-paired test at the 95% confidence level.

A novel spectrophotometric method development and validation of Tenagliptin in its Tablet dosages form

The aim of present work was to develop a new, economical & simple analytical method of Teneligliptin & its validation as per International Conference on Harmonization (ICH) guideline, which is a new antidiabetic drug that is used to treat Non-Insulin Dependent Diabetis Melitus (NIDDM) patients. A sensitive and specific Ultra Violet (UV) Visible method was developed & the analysis was carried out by using Shimazdu 1800 Spectrophotometer, 0.1(N) NaOH was used as a solvent. The UV- Visible Spectrophotometric estimation was carried out at a λ max of 242 nm using 1cm thick quartz cell. Validation of the newly developed method was performed as per International Conference on Harmonization (ICH) Q2R1 guideline in the following parameters: Calibration curve, Accuracy, Precision etc. Newly developed method obeys Beer’s-Lambert’s law in the concentration range of 5 - 25 μg / ml, whereas correlation coefficient value is less than 1. The percent amount of drug estimated by this developed method was 100.91 %, which is very close to 100 %. The validation parameters like Accuracy, Precision, Linearity, Range, Limit of detection (LOD) & Limit of Quantification (LOQ) were studied for the developed method and was found to be within the limits.
 Keywords: Teneligliptin, Validation, Method, Spectroscopy etc.