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1.
Phytochem Anal ; 2024 May 27.
Article in English | MEDLINE | ID: mdl-38802067

ABSTRACT

INTRODUCTION: Ginger (Zingiber officinale Rosc.) varies widely due to varying concentrations of phytochemicals and geographical origin. Rapid non-invasive quality and traceability assessment techniques ensure a sustainable value chain. OBJECTIVE: The objective of this study is the development of suitable machine learning models to estimate the concentration of 6-gingerol and check traceability based on the spectral fingerprints of dried ginger samples collected from Northeast India and the Indian market using near-infrared spectrometry. METHODS: Samples from the market and Northeast India underwent High Performance Liquid Chromatographic analysis for 6-gingerol content estimation. Near infrared (NIR) Spectrometer acquired spectral data. Quality prediction utilized partial least square regression (PLSR), while fingerprint-based traceability identification employed principal component analysis and t-distributed stochastic neighbor embedding (t-SNE). Model performance was assessed using RMSE and R2 values across selective wavelengths and spectral fingerprints. RESULTS: The standard normal variate pretreated spectral data over the wavelength region of 1,100-1,250 nm and 1,325-1,550 nm showed the optimal calibration model with root mean square error of calibration and R2 C (coefficient of determination for calibration) values of 0.87 and 0.897 respectively. A lower value (0.24) of root mean square error of prediction and a higher value (0.973) of R2 P (coefficient of determination for prediction) indicated the effectiveness of the developed model. t-SNE performed better clustering of samples based on geographical location, which was independent of gingerol content. CONCLUSION: The developed NIR spectroscopic model for Indian ginger samples predicts the 6-gingerol content and provides geographical traceability-based identification to ensure a sustainable value chain, which can promote efficiency, cost-effectiveness, consumer confidence, sustainable sourcing, traceability, and data-driven decision-making.

2.
Phytochem Anal ; 34(5): 507-517, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37192739

ABSTRACT

INTRODUCTION: Black rice (Oryza sativa L.), which is rich in polyphenols and flavonoids, is indigenous to Northeast India, specifically Manipur, and traditionally consumed for its protective effects on human health. Due to its economic value, it is crucial to evaluate the quality of different black rice varieties to authenticate their therapeutic and nutritional properties. OBJECTIVE: We aimed to evaluate the quality of pre- and post-marketed black rice samples by a validated high-performance thin layer chromatography method and determine variations of total phenolics and total flavonoids with antioxidant potential. MATERIAL AND METHODS: The ferulic acid, gallic acid, quercetin, and caffeic acid contents of three black rice varieties-Poireiton, Amubi, and Sempak-along with two marketed samples of Amubi from Manipur, India, were quantified based on standards. Antioxidant potential was measured by the 2,2-diphenyl-1-picryl-hydrazyl hydrate free radical scavenging assay. RESULTS: The highest and lowest relative biomarker contents were found in hydroalcoholic extracts of Amubi [caffeic acid (1.43% w/w), ferulic acid (1.15% w/w), quercetin (0.6% w/w), and gallic acid (0.39% w/w)] and the marketed sample Var. Amubi from Kakching District, respectively. Pearson's correlation coefficient of antioxidant potential with phenolic and flavonoid content showed a moderate to strong correlation for all samples. CONCLUSION: This validated, rapid, accurate standardization method for black rice varieties will be beneficial for the quality evaluation of black rice and its derived products. It will also be helpful to authenticate the nutritional benefits for the consumers.


Subject(s)
Antioxidants , Oryza , Humans , Antioxidants/analysis , Quercetin , Oryza/chemistry , Plant Extracts/chemistry , India , Flavonoids/analysis , Phenols/analysis , Gallic Acid
3.
Article in English | MEDLINE | ID: mdl-37010684

ABSTRACT

In this work, post-synthetic effective acid (HNO3) and base (NaOH) etching technique are used to create hierarchical mordenite having different pore structure. The powder X-ray diffraction (P-XRD) technique was used to confirm the crystalline structure of the base-modified and acid-modified mordenite. Field emission-scanning electron microscope (FE-SEM) was employed to confirm the structural morphology of the materials. The modified mordenite was further characterised by inductive coupled plasma-optical emission spectrometry (ICP-OES), N2 adsorption-desorption isotherms, thermogravimetric analysis (TGA), and acid-base titration, to confirm the structural integrity, presence of active acidic sites, and other vital parameters. The structure was well conserved after the change, as evidenced by the characterisation. The toluene benzylation with benzyl alcohol using hierarchical mordenite and H-mordenite produced mono-benzylated toluene. Comparison between acid treated, base treated, and H-mordenite was done. All samples were catalytically active as proved by the catalytic result in the benzylation reaction. The results show that the base alteration dramatically enhances the mesoporous surface area of H-mordenite. Furthermore, the acid-treated mordenite had the highest benzyl alcohol conversion (75%), but the base-modified mordenite had benzyl alcohol conversion of 73% with the highest mono-benzylated toluene selectivity (61%). The process was further optimised by varying the reaction temperature, duration, and catalyst quantity. Gas chromatography (GC) was used to evaluate the reaction products and gas chromatography-mass spectrometry (GC-MS) was used to confirm them. Introduction of mesoporosity in the microporous mordenite was found to have significant effect on their catalytic activity.

4.
Environ Sci Pollut Res Int ; 30(16): 46159-46174, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36710314

ABSTRACT

The generation of wastewater has increased rapidly with the expansion of industries, hence, posing a risk to human health and the environment. The development of novel materials and technologies for textile wastewater treatment is constantly evolving. In this work, the photocatalytic degradation of methylene blue employing ZSM-5 zeolite-doped polyaniline composites is presented. To fabricate ZSM-5-based polyaniline (PANI) composites, the simple approach of in situ oxidative polymerization has been adopted. Different weight ratios of ZSM-5 have been used for the synthesis, and samples have been labelled as PAZe-1, PAZe-5, and PAZe-10. Different characterization techniques were used to characterize the prepared composites, including field-emission scanning electron microscope (FESEM), transmission electron microscope (TEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and thermo-gravimetry analysis (TGA). The photocatalytic performance of polyaniline, ZSM-5, and their composites was assessed by monitoring the degradation of methylene blue in the presence of visible light. Degradation results of the polyaniline-doped composites were found to be better than that of the polyaniline alone. When the photocatalytic efficiencies of different composites were compared, the PAZe-1 showed the best performance, with 99.9% degradation efficiency after 210 min of irradiation, while PANI, PAZe-5, PAZe-10, and ZSM-5 show 38%, 82%, 71%, and 99% removal efficiency. Apart from methylene blue, the composite PAZe-1 was further explored for the degradation of other organic pollutants such as methyl orange, chlorpyrifos, 2,4-dichlorophenoxy acetic acid, and p-nitroaniline. To determine the reactive species involved in the photocatalysis mechanism, scavenger studies were performed.


Subject(s)
Methylene Blue , Zeolites , Humans , Spectroscopy, Fourier Transform Infrared , Water
5.
Nanomaterials (Basel) ; 12(18)2022 Sep 14.
Article in English | MEDLINE | ID: mdl-36144986

ABSTRACT

All humans and animals need access to clean water in their daily lives. Unfortunately, we are facing water scarcity in several places around the world, and, intentionally or unintentionally, we are contaminating the water in a number of ways. The rise in population, globalization, and industrialization has simultaneously given rise to the generation of wastewater. The pollutants in wastewater, such as organic contaminants, heavy metals, agrochemicals, radioactive pollutants, etc., can cause various ailments as well as environmental damage. In addition to the existing pollutants, a number of new pollutants are now being produced by developing industries. To address this issue, we require some emerging tools and materials to remove effluents from wastewater. Zeolites are the porous aluminosilicates that have been used for the effective pollutant removal for a long time owing to their extraordinary adsorption and ion-exchange properties, which make them available for the removal of a variety of contaminants. However, zeolite alone shows much less photocatalytic efficiency, therefore, different photoactive materials are being doped with zeolites to enhance their photocatalytic efficiency. The fabrication of zeolite-based composites is emerging due to their powerful results as adsorbents, ion-exchangers, and additional benefits as good photocatalysts. This review highlights the types, synthesis and removal mechanisms of zeolite-based materials for wastewater treatment with the basic knowledge about zeolites and wastewater along with the research gaps, which gives a quality background of worldwide research on this topic for future developments.

6.
Dalton Trans ; 51(19): 7436-7454, 2022 May 17.
Article in English | MEDLINE | ID: mdl-35411894

ABSTRACT

The highly luminescent complex [CdQ2(H2O)2] (1) shows ultra-selectivity and high sensitivity to the explosive organo-toxin trinitrophenol (TNP). This detection is extremely fast with a high quenching constant (5.3 × 104 M-1) and a very low limit of detection (LOD) of 137 nM/59 ppb. This motivated us to detect the lethal carcinogenic arsenical drug roxarsone (ROX), which is reported here for the first time. The quenching constant and LOD for ROX using 1 were found to be 4.9 × 104 M-1 and 86 nM (or 37 ppb), respectively. Moreover, the probe also recognizes three lethal toxic oxo-anions (MnO4-, Cr2O72- and CrO42-) with outstanding quenching constant (2.2 × 104 M-1, 1.4 × 104 M-1 and 1.1 × 104 M-1) and very low LODs (141 nM/61 ppb, 178 nM/78 ppb and 219 nM/95 ppb). Compared to the previously reported homogeneous sensing nature of the discrete complexes, our complex showed the detection of toxic pollutants in a heterogeneous manner, which results in high recyclability and hence multi-cycle sensing capability. Interestingly, 1 shows the possibility for real-time monitoring through naked eye detection by visible colorimetric changes in solid, solution and strip paper methods, i.e., triphasic detection ability. In addition, the sensor also exhibited the cross-sensing ability for these pollutants. The experimental sensing mechanism is strongly supported by the exhaustive theoretical investigation. Based on the fluorescence signal shown by each analyte, an integrated AND-OR logic gate is constructed. Furthermore, the sensing ability of 1 remains intact towards the detection of versatile real field samples including lethal carcinogenic arsenical drug roxarsone in the real food sample.


Subject(s)
Environmental Pollutants , Roxarsone , Anions , Cadmium , Colorimetry , Water
7.
Talanta ; 236: 122837, 2022 Jan 01.
Article in English | MEDLINE | ID: mdl-34635227

ABSTRACT

A quartz crystal microbalance (QCM) sensor was developed in this study with the vegetable oil from olive (OLV-QCM) to detect an important volatile organic compound, ß-pinene in Indian cardamom. Hydrophobic vegetable oil from olive, which contains oleic acid and omega-9, a monounsaturated fatty acid was found to be suitable for binding ß-pinene through non-covalent bonds. The fabricated QCM sensor coating was examined with the field emission scanning electron microscope (FESEM) and Fourier-transform infrared spectroscopy (FTIR) to determine its surface morphology and chemical compositions. The sensitivity, reproducibility, repeatability, and reusability were studied for the developed sensor. Notably, the sensor was observed to be highly selective towards ß-pinene as compared to the other volatile components present in cardamom. The limit of detection (LOD) and limit of quantitation (LOQ) parameters were determined as 5.57 mg L-1 and 18.57 mg L-1, respectively. Moreover, the adsorption isotherm models of the sensor were studied to validate the physical adsorption affinity towards ß-pinene applying Langmuir, Freundlich, and Langmuir-Freundlich isotherm models. The sensor showed a correlation factor of 0.99 with the peak area percentage of gas chromatography-mass spectrometry (GC-MS) analysis for ß-pinene in cardamom samples. The sensor was prepared with natural vegetable oil, unlike health hazard chemicals. In addition to this, the low-cost, easy fabrication process ensured the suitability of the sensor for practical deployment.


Subject(s)
Elettaria , Molecular Imprinting , Bicyclic Monoterpenes , Plant Oils , Polymers , Quartz Crystal Microbalance Techniques , Reproducibility of Results
8.
Sensors (Basel) ; 21(13)2021 Jun 29.
Article in English | MEDLINE | ID: mdl-34210087

ABSTRACT

We report on the development of a simple and cost-effective potentiometric sensor array that is based on manual "drawing" on the polymeric support with the pencils composed of graphite and different types of zeolites. The sensor array demonstrates distinct sensitivity towards a variety of inorganic ions in aqueous media. This multisensor system has been successfully applied to quantitative analysis of 100 real-life surface waters sampled in Mahananda and Hooghly rivers in the West Bengal state (India). Partial least squares regression has been utilized to relate responses of the sensors to the values of different water quality parameters. It has been found that the developed sensor array, or electronic tongue, is capable of quantifying total hardness, total alkalinity, and calcium content in the samples, with the mean relative errors below 18%.


Subject(s)
Electronic Nose , Water Quality , Least-Squares Analysis , Potentiometry , Rivers
9.
Front Pharmacol ; 12: 629833, 2021.
Article in English | MEDLINE | ID: mdl-34025404

ABSTRACT

Andrographis paniculata (Burm. F) Nees, has been widely used for upper respiratory tract and several other diseases and general immunity for a historically long time in countries like India, China, Thailand, Japan, and Malaysia. The vegetative productivity and quality with respect to pharmaceutical properties of Andrographis paniculata varies considerably across production, ecologies, and genotypes. Thus, a field deployable instrument, which can quickly assess the quality of the plant material with minimal processing, would be of great use to the medicinal plant industry by reducing waste, and quality grading and assurance. In this paper, the potential of near infrared reflectance spectroscopy (NIR) was to estimate the major group active molecules, the andrographolides in Andrographis paniculata, from dried leaf samples and leaf methanol extracts and grade the plant samples from different sources. The calibration model was developed first on the NIR spectra obtained from the methanol extracts of the samples as a proof of concept and then the raw ground samples were estimated for gradation. To grade the samples into three classes: good, medium and poor, a model based on a machine learning algorithm - support vector machine (SVM) on NIR spectra was built. The tenfold classification results of the model had an accuracy of 83% using standard normal variate (SNV) preprocessing.

10.
Nano Energy ; 79: 105387, 2021 Jan.
Article in English | MEDLINE | ID: mdl-32983849

ABSTRACT

Usage of a face mask has become mandatory in many countries after the outbreak of SARS-CoV-2, and its usefulness in combating the pandemic is a proven fact. There have been many advancements in the design of a face mask and the present treatise describes a face mask in which a simple triboelectric nanogenerator (TENG) with an electrocution layer may serve the purpose of filtration and deactivation of SARS-CoV-2. The proposed mask is designed with multilayer filters, in which the inner three layers act as a triboelectric (TE) filter and the outer one as an electrocution layer (EL). The viral particles experience a mildshock in EL due to the electric field produced between the electrocution layers by contact electrification. Four pairs of triboelectric series fabrics, i.e. polyvinylchloride (PVC)-nylon, polypropylene (PP)-polyurethane (PU), latex rubber-PU, polyimide (PI)-nylon are studied to establish the efficacy of the mask. The motional force exerted on triboelectric filter materials can produce sufficient electric power to activate EL. The proposed mask can be used by a wide range of people because of its triboelectric self-powering (harvesting mechanical energy from daily activities, e.g. breathing, talking or other facial movements) functionalities to ensure effective filtration efficiency. More importantly, it is expected to be potentially beneficial to slow down the devastating impact of COVID-19.

11.
Talanta ; 206: 120176, 2020 Jan 01.
Article in English | MEDLINE | ID: mdl-31514900

ABSTRACT

Nd2O3 nanoparticle grafted graphene nanocomposite (NOGG) was synthesized by sonochemical treatment of an ethanolic dispersion of Nd2O3 nanoparticle and graphene. All the synthesized materials were characterized by XRD, FESEM, TEM, and BET. The NOGG has a high specific surface area (272 m2g-1) with narrowly distributed pores with diameter centered at 2.8, 6.0 and 7.50 nm. A composite paste electrode of 1:1 (w/w) NOGG and graphite was showed better electrochemical properties. The NOGG/GP electrode showed all around better electrocatalytic activity towards Adrenaline (AD) and Tyrosine (TY) than TRG/GP and bare GP electrode. According to cyclic voltammograms, AD and TY oxidized irreversibly through adsorption control process. DPV peak currents were measured at 378 ±â€¯15 mV and 787 ±â€¯15 mV for determination AD and TY respectively using the NOGG/GP electrode as the peak intensities were highest at those potentials. Under the optimized experimental condition, the determination ranges for AD and TY showed two linear ranges, those were 0.1-5-130 µM and 0.1-3-120 µM, respectively. A detection limit of AD and TY was measured (m-LOD) to be 50 nM and 40 nM, respectively. The modified electrode was reproducible, selective, highly sensitive and also employed for analysis of AD and TY in biological and pharmaceutical samples with excellent recovery.

12.
Trans Indian Natl Acad Eng ; 5(2): 181-185, 2020.
Article in English | MEDLINE | ID: mdl-38624324

ABSTRACT

The outbreak of the SARS-CoV-2 virus is causing loss of lives and property all over the world. There have been more than 2.1 million cases of COVID-19 with a death of more than 1.2 lakh patients worldwide and the numbers are still rising. The virus spreads rapidly by the droplets coming out from the nose and mouth of an infected person (Sandoiu in Why does SARS-CoV-2 spread so easily? Medical news today, 2020 https://www.medicalnewstoday.com/articles/why-does-sars-cov-2-spread-so-easily). In this situation, proper quarantining and monitoring of the already infected patients are very essential. In cases where patients need to be transferred to different locations by ambulances, monitoring of these ambulances by the traffic police can help to ensure distancing and faster movement of the vehicle inside the city. This paper presents the development of a Real-time Global Positioning System-based tracking app for the ambulances carrying COVID-19 patients which would help traffic police to ensure distancing the patients from the public.

13.
Trans Indian Natl Acad Eng ; 5(2): 225-228, 2020.
Article in English | MEDLINE | ID: mdl-38624404

ABSTRACT

The outbreak of COVID-19 has taken a large number of lives since 2019 and the death toll continues to increase all over the world. Recent data reports that about 27 lacs of people are infected with this virus till date and around 2 lacs are dead due to this pandemic. The situation in India is no way better. In India, almost all the states have become victim of this deadly pandemic. Considering the enormous population in India, citizens here are facing acute shortage of detection kits and many are dying even before the knowledge of their infection. The present treatise proposes a molecularly imprinted polymer (MIP) based technique for simple and rapid detection of COVID-19. The technique will be inexpensive, selective, reusable and easy to handle. It has been already implemented in our laboratory in order to detect the taste contributing agents found in tea. This article discusses the detailed methodology and the resultant analytical characteristic of the sensors developed so far and also outlines the suitability of the MIP technique towards fabrication of testing kits for rapid detection of COVID-19.

14.
Trans Indian Natl Acad Eng ; 5(2): 163-179, 2020.
Article in English | MEDLINE | ID: mdl-38624426

ABSTRACT

The World Health Organization has declared the outbreak of the novel coronavirus, Covid-19 as pandemic across the world. With its alarming surge of affected cases throughout the world, lockdown, and awareness (social distancing, use of masks etc.) among people are found to be the only means for restricting the community transmission. In a densely populated country like India, it is very difficult to prevent the community transmission even during lockdown without social awareness and precautionary measures taken by the people. Recently, several containment zones had been identified throughout the country and divided into red, orange and green zones, respectively. The red zones indicate the infection hotspots, orange zones denote some infection and green zones indicate an area with no infection. This paper mainly focuses on development of an Android application which can inform people of the Covid-19 containment zones and prevent trespassing into these zones. This Android application updates the locations of the areas in a Google map which are identified to be the containment zones. The application also notifies the users if they have entered a containment zone and uploads the user's IMEI number to the online database. To achieve all these functionalities, many tools, and APIs from Google like Firebase and Geofencing API are used in this application. Therefore, this application can be used as a tool for creating further social awareness about the arising need of precautionary measures to be taken by the people of India.

15.
Trans Indian Natl Acad Eng ; 5(2): 417-427, 2020.
Article in English | MEDLINE | ID: mdl-38624496

ABSTRACT

COVID-19 has created a devastating pandemic, infecting more than 200 countries in its wake, only sparing Antarctica. The virus dissociates ferrous ion from the porphyrin ring of heme of haemoglobin-thus hampering the oxygen and carbon dioxide exchange in the lung and tissue. The toxic effect of ferrous (Fe2+) ions and carbon dioxide causes lung damage giving rise to severe respiratory distress and an often observed clotting disorder. Serum ferritin level is increased along with the rise of serum LDH, d-dimer, serum IL-6 and cardiac troponin. Associated leukocytosis, occasional lymphocytopenia and radiological changes of the lung are the pathological hallmarks of the disease. All these parameters including other clinical data such as age, fever, gender and associated co-morbidities may be used as a Risk Assessment tool for COVID-19 before the report of real-time polymerase chain reaction (RT PCR) is available. A timely intervention can contribute to rescuing millions from an untimely death.

16.
Sensors (Basel) ; 19(9)2019 Apr 29.
Article in English | MEDLINE | ID: mdl-31035734

ABSTRACT

The paper describes a wide-range practical application of the potentiometric multisensor system (MS) (1) for integral safety evaluation of a variety of natural waters at multiple locations, under various climatic conditions and anthropogenic stress and (2) for close to real consistency evaluation of waste water purification processes at urban water treatment plants. In total, 25 natural surface water samples were collected around St. Petersburg (Russia), analyzed as is, and after ultrasonic treatment. Toxicity of the samples was evaluated using bioassay and MS. Relative errors of toxicity assessment with MS in these samples were below 20%. The system was also applied for fast determination of integral water quality using chemical oxygen demand (COD) values in 20 samples of water from river and ponds in Kolkata (India) and performed with an acceptable precision of 20% to 22% in this task. Furthermore, the MS was applied for fast simultaneous evaluation of COD, biochemical oxygen demand, inorganic phosphorous, ammonia, and nitrate nitrogen at two waste water treatment plants (over 320 samples). Reasonable precision (within 25%) of such analysis is acceptable for rapid water safety evaluation and enables fast control of the purification process. MS proved to be a practicable analytical instrument for various real-world tasks related to water safety monitoring.


Subject(s)
Electronic Nose , Potentiometry/methods , Wastewater/analysis , Water Quality , Animals , Biological Oxygen Demand Analysis , Daphnia/drug effects , Electronic Data Processing , Least-Squares Analysis , Potentiometry/instrumentation , Principal Component Analysis , Wastewater/toxicity , Water Purification
17.
Article in English | MEDLINE | ID: mdl-31034329

ABSTRACT

This paper investigates the feasibility of Fourier transform near-infrared (FT-NIR) spectroscopy, a fast and easy method based on chemometric methods to detect corn starch illegally added to turmeric powder. In this work, the pure turmeric powders were blended with corn starch to generate different concentrations (1-30%)(w/w) of starch-adulterated turmeric samples. The reflectance spectra of total of 224 samples were taken by FT-NIR spectroscopy. The exploratory data analysis was done by principal component analysis (PCA). The starch related peaks were selected by variable importance in projection (VIP) method and were explored by examination of original reflectance spectra, 1st derivative spectra, PCA loadings and ß coefficients plot of the partial least square regression (PLSR) model. The coefficient of determination (R2) and root-mean-square error of partial least square regression (PLSR) models were found to be 0.91-0.99 and 0.23-1.3%, respectively, depending on the pre-processing techniques of spectral data. The figure of merit (FOM) of the model was found with the help of net analyte signal (NAS) theory.


Subject(s)
Curcuma/chemistry , Food Contamination/analysis , Fourier Analysis , Starch/analysis , Multivariate Analysis , Powders , Spectroscopy, Near-Infrared
18.
J Food Sci Technol ; 55(12): 4867-4876, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30482982

ABSTRACT

This paper reports on the development of an integrated leaf quality inspecting system using near infrared reflectance (NIR) spectroscopy for quick and in situ estimation of total polyphenol (TP) content of fresh tea leaves, which is the most important quality indicator of tea. The integrated system consists of a heating system to dry the fresh tea leaves to the level of 3-4% moisture, a grinding and sieving system fitted with a 250 micron mesh sieve to make fine powder from the dried leaf. Samples thus prepared are transferred to the NIR beam and TP is measured instantaneously. The wavelength region, the number of partial least squares (PLS) component and the choice of preprocessing methods are optimized simultaneously by leave-one-sample out cross-validation during the model calibration. In order to measure polyphenol percentage in situ, the regression model is developed using PLS regression algorithm on NIR spectra of fifty-five samples. The efficacy of the model developed is evaluated by the root mean square error of cross-validation, root mean square error of prediction and correlation coefficient (R2) which are obtained as 0.1722, 0.5162 and 0.95, respectively.

19.
Mikrochim Acta ; 185(11): 513, 2018 10 23.
Article in English | MEDLINE | ID: mdl-30353270

ABSTRACT

Titanium dioxide nanoparticles (NPs) were synthesized by a sol-gel method from hexafluorotitanic acid using poly(ethylene glycol) as a capping agent. The crystal structure and morphology of the NPs were characterized by X-ray diffraction, FESEM, and TEM. The NPs were used to modify a graphite paste electrode for simultaneous determination of uric acid (UA) and guanine (GU). The effect of calcination temperature on crystal structure and electrocatalytic activity was investigated. The electrochemical responses to UA and GU at bare GP, TiO2-350/GP, and TiO2-600/GP electrodes were compared. The DPV oxidation peaks of UA and GU were found to be strongest at around 304 and 673 mV, respectively, against Ag/AgCl reference electrode, and this are well separated for effective simultaneous determination. UA and GU can be simultaneously determined by this method. Response is linear within the range 0.1-500 µM and 0.1-40 µM for UA and GU, respectively. The detection limits are 70 nM for UA and 50 nM for GU (at an S/N  ratio of 3). The TiO2-600/GP electrode showed excellent analytical performance when analyzing spiked urine and serum samples. Graphical abstract A graphical representation of cubic TiO2 nanoparticle formation during hydrolysis through sol-gel process.

20.
Talanta ; 144: 329-40, 2015 Nov 01.
Article in English | MEDLINE | ID: mdl-26452830

ABSTRACT

The present review evaluates the key modules of the electronic nose, a biomimetic system, with specific examples of applications to industrial emissions monitoring and measurement. Regulations concerning the odor control are becoming very strict, due to ever mounting environmental pollution and its subsequent consequences and it is advantageous to employ real time measurement system. In this perspective, systems like the electronic nose are an improved substitute for assessing the complex industrial emissions over other analytical techniques (odorant concentration measurement) and olfactometry (odor concentration measurement). Compared to tools like gas chromatography, electronic nose systems are easy to develop, are non-destructive and useful for both laboratory and on field purposes. Although there has been immense development of more sensitive and selective sensor arrays and advanced data mining techniques, there have been limited reports on the application of electronic nose for the measurement of industrial emissions. The current study sheds light on the practical applicability of electronic nose for the effective industrial odor and gaseous emissions measurement. The applications categorization is based on gaseous pollutants released from the industries. Calibration and calibration transfer methodologies have been discussed to enhance the applicability of electronic nose system. Further, industrial gas grab sampling technique is reviewed. Lastly, the electronic mucosa system, which has the ability to overcome the flaws of electronic nose system, has been examined. The review ends with the concluding remarks describing the pros and cons of artificial olfaction technique for the industrial applications.

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