Hypochlorous acid (HOCl) was crucial for maintaining the homeostasis in cells and plays vital roles in many physiological and pathological processes. In this work, a highly selective fluorescent probe for hypochlorous acid in living cells was constructed and prepared based on a naphthalene derivative. A naphthalene derivative was utilized as the fluorescent group, and N,N-dimethylthiocarbamate was applied as the selective recognition site for HOCl. Before adding HOCl, the fluorescent probe exhibited weak fluorescence. Upon adding HOCl, the fluorescent probe displayed remarkable fluorescence enhancement. The fluorescence intensity at 502&#x2009;nm showed a linear response to the concentration of HOCl from 3.0&#x2009;&#xd7;&#x2009;10&#x2212;7 to 1.0&#x2009;&#xd7;&#x2009;10&#x2212;5&#x2009;mol&#xb7;L&#x2212;1. The detection limit was estimated to be 1.5&#x2009;&#xd7;&#x2009;10&#x2212;7&#x2009;mol&#xb7;L&#x2212;1 for HOCl. The fluorescent probe showed fast response and outstanding selectivity toward HOCl. It owned good biocompatibility and had also been successfully applied in the confocal imaging of exogenous and endogenous HOCl in living cells.

Jingguo Sun

Junhong Xu

Qiujuan Ma

Guojiang Mao

Nannan Zhu

Meiju Tian

Linke Li

Shuzhen Liu

A Highly Selective Fluorescent Probe for Hypochlorous Acid in Living Cells Based on a Naphthalene Derivative

Vegetables are consumed worldwide in fresh as well as processed forms. Pumpkin is considered as an important vegetable due to its nutritional values. The objective of this study was to evaluate all the analytical parameters and improve the performance of the methods for the determination of &#x3b2;-carotene in pumpkin flesh, peel, and seed samples using UV-VIS, NIR, and FTIR methods. &#x3b2;-Carotene was measured at 453&#x2009;nm using the UV-VIS method which showed linear range, 0.1 to 12&#x2009;&#xb5;g/mL; R2, 0.999; LOD, 0.034&#x2009;&#xb5;g/mL; LOQ, 0.1&#x2009;&#xb5;g/mL; RSD, 1.5&#x0025; to 11&#x0025;; and percent recovery, 83&#x0025; to 93&#x0025;. &#x3b2;-Carotene was also measured at 1415&#x2009;nm using NIR and at 1710&#x2009;cm&#x2212;1 using FTIR spectroscopic methods. The NIR method exhibited linear range, 12.5 to 250&#x2009;&#xb5;g/mL; R2, 0.999; LOD, 3.4&#x2009;&#xb5;g/mL; LOQ, 10, &#xb5;g/mL; RSD, 1.8&#x0025; to 11&#x0025;; and percent recovery, 92&#x0025; to 96&#x0025;, while the FTIR method exhibited linear range, 4 to 100&#x2009;&#xb5;g/mL; R2, 0.999; LOD, 1.3&#x2009;&#xb5;g/mL; LOQ, 3.9&#x2009;&#xb5;g/mL; RSD, 0.69&#x0025; to 10&#x0025;; and percent recovery, 95&#x0025; to 96&#x0025;. The characteristic analytical data indicated that any of the three newly developed methods could be used for the determination of &#x3b2;-carotene in the pumpkin flesh, peel, and seeds. Acetone was used as the extraction solvent for the UV-VIS and NIR spectroscopic methods, and acetonitrile was used as the extraction solvent for the FTIR method. Content of &#x3b2;-carotene was found higher in pumpkin peel (340&#x2013;445&#x2009;&#xb5;g/g), followed by pumpkin flesh (317&#x2013;341&#x2009;&#xb5;g/g) and pumpkin seed (12&#x2013;17&#x2009;&#xb5;g/g) by the UV-VIS method. &#x3b2;-Carotene content was obtained ((376&#x2013;451&#x2009;&#xb5;g/g) and (289&#x2013;313&#x2009;&#xb5;g/g); (210&#x2013;287&#x2009;&#xb5;g/g) and (102&#x2013;148&#x2009;&#xb5;g/g)) using NIR and FTIR methods in pumpkin peel and flesh, respectively. &#x3b2;-Carotene was obtained higher from pumpkin peel by all the three methods than from pumpkin flesh and seed. The &#x3b2;-carotene content in the pumpkin seed was not detected by NIR and FTIR spectroscopic methods.

Mulu Hagos

Mesfin Redi-Abshiro

Bhagwan Singh Chandravanshi

Estifanos Ele Yaya

Development of Analytical Methods for Determination of &#x3b2;-Carotene in Pumpkin (Cucurbita maxima) Flesh, Peel, and Seed Powder Samples

The exogenous lipolytic activities of Kocuria sp. have been recognized earlier but the genus further contains many more unexplored strains. In this study, the extracellular lipase activity of Kocuria flava Y4 (GenBank accession no. MT773277), isolated from Dioscorea villosa during our previous study, was regulated by different physicochemical parameters, such as pH, temperature, shaking speed, and incubation time. For efficient immobilization of the extracellular lipase, 4&#x0025; sodium alginate, 50 mL of 25&#x2009;nM CaCl2.2H2O solution, and 15&#x2009;min. Hardening time of gel beads in calcium chloride was used. For the first time, K. flava Y4 lipase was purified using ammonium sulphate precipitation followed by dialysis and DEAE-Sepharose anion exchange chromatography with Sepharose-6B gel filtration chromatography, yielding &#x223c;15-fold purified lipase with a final yield of 96&#x2009;U/mL. The SDS-PAGE of purified lipase displayed a single strong band, indicating a monomeric protein of 45&#x2009;kDa. At a temperature of 35&#xb0;C and pH 8, the purified lipase showed maximum hydrolytic activity. Using p-nitrophenyl acetate (p-NPA) as the hydrolysis substrate, the values of Km and Vmax derived from the Lineweaver&#x2013;Burk plot were 4.625&#x2009;mM and 125&#x2009;mol/min&#x2212;1mg&#x2212;1, respectively.

Adyasa Barik

Sudip Kumar Sen

Geetanjali Rajhans

Sangeeta Raut

Purification and Optimization of Extracellular Lipase from a Novel Strain Kocuria flava Y4

An effective analytical method is requisite to ensure the accurate identification and quantification of drug(s), either in bulk material or in complex matrices, which form part of finished pharmaceutical products. For the purpose of a pharmaceutical formulation study, it became necessary to have a simple, yet robust and reproducible reversed-phase HPLC method for the simultaneous detection and quantification of lamivudine (3TC), tenofovir disoproxil fumarate (TDF), and dolutegravir sodium (DTG) in bulk form, complex polymeric matrices, and during drug release studies. A suitable method was developed using a Kinetex&#xae; C18, 250&#x2009;&#xd7;&#x2009;4.6&#x2009;mm column as stationary phase and a mobile phase consisting of 50&#x2009;:&#x2009;50 v/v methanol and water with 1&#x2009;mL orthophosphoric acid, with a flow rate of 1.0&#x2009;mL/min and column temperature maintained at 35&#xb0;C. A detection wavelength of 260&#x2009;nm and an injection volume of 10&#x2009;&#x3bc;L were used. The method was validated according to the International Conference on Harmonization (ICH) guideline Q2 (R1), and the parameters of linearity and range, accuracy, precision, specificity, limit of detection (LOD), limit of quantification (LOQ), robustness, and stability were all determined. Acceptable correlation coefficients for linearity (R2) of &#x3e;0.998 for each of the three drugs were obtained. The LOD was quantified to be 56.31&#x2009;&#x3bc;g/mL, 40.27&#x2009;&#x3bc;g/mL, and 7.00&#x2009;&#x3bc;g/mL for 3TC, TDF, and DTG, respectively, and the LOQ was quantified as 187.69&#x2009;&#x3bc;g/mL, 134.22&#x2009;&#x3bc;g/mL, and 22.5&#x2009;&#x3bc;g/mL for 3TC, TDF, and DTG, respectively. In relation to all the determined validation parameters, this method proves to be suitable for the accurate identification and quantification of the three ARVs, either alone or in combination, as well as when incorporated into polymeric matrices. Furthermore, the method proves to be suitable to detect degradation of the compounds.

Omobolanle Ayoyinka Omoteso

Marnus Milne

Marique Aucamp

The Validation of a Simple, Robust, Stability-Indicating RP-HPLC Method for the Simultaneous Detection of Lamivudine, Tenofovir Disoproxil Fumarate, and Dolutegravir Sodium in Bulk Material and Pharmaceutical Formulations

The development of low-cost adsorbent coal FA (Kosovo A) for pesticide removal is an important area of scientific research. With this study, we show the potential of adsorption of coal FA (Kosovo A) for the removal of benalaxyl and atrazine from water. We have found that the amount of adsorbed benalaxyl and atrazine increases with an increasing amount of coal FA (Kosovo A) in solution. The maximum capacity coal FA (Kosovo A) to adsorb benalaxyl and atrazine was found to be 0.46 and 0.45&#x2009;mg/g according to the Freundlich equation and 3.48 and 3.33&#x2009;mg/g according to the Langmuir equation. The Freundlich adsorption equation better explains the adsorption results of pesticides (benalaxyl and atrazine) in coal FA (Kosovo A), as the values of the recovery coefficient (R2) were higher in Freundlich equation than the Langmuir equation. The adsorption isotherms were of type L and show that the adsorption efficiency of the coal FA (Kosovo A) depends on the initial concentration of benalaxyl and atrazine in solution and the maximum removal of benalaxyl and atrazine was achieved at concentrations less than 10&#x2009;&#x00B5;g/ml. This study&#x2019;s results are expected to have implications for the use of coal FA (Kosovo A) for the removal of pesticides from water.

Esad Behrami

Kledi Xhaxhiu

Bedri Dragusha

Arianit Reka

Adelaida Andoni

Xhuljeta Hamiti

Spiro Drushku

The Removal of Atrazine and Benalaxyl by the Fly Ash Released from Kosovo A Power Plant

In this study, the effects of different processing techniques on the chemical components of Raphani Semen (RS) were evaluated. An established high-performance liquid chromatography (HPLC) method was adopted for the simultaneous determination of glucoraphanin, sinapine thiocyanate, raphanin, and erucic acid in the fried products of Raphani Semen to evaluate the chemical changes during frying processing as well as optimize the best frying technology of Raphani Semen. Then, the chemical components in the fried Raphani Semen were identified by ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). A total of 54 compounds in processed Raphani Semen were identified by UPLC-Q-TOF-MS. The results showed that the content of glucoraphanin and sinapine thiocyanate was the highest in the fried products at 130&#xb0;C for 10&#x2009;min, and the effect of &#x201c;Enzyme Killing and Glycosides Preserving&#x201d; was the best. Therefore, this condition was chosen as the best frying technology of Raphani Semen. This study provided a more scientific basis for evaluation of the quality of Raphani Semen fried products and optimization of the frying technology of Raphani Semen.

Sijia Gao

Jirui Wang

Lei Cheng

Yuxin Fan

Weihan Qin

Yunhong Wang

Yanlei Guo

Xiaomei Zhang

Yong Yang

Evaluation of the Effects of Processing Technique on Chemical Components in Raphani Semen by HPLC and UPLC-Q-TOF-MS

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International Journal of Analytical Chemistry publishes research reporting new experimental results and chemical methods, especially in relation to important analytes, difficult matrices, and topical samples.

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Chief Editor, Professor Charles L. Wilkins, is a Distinguished Professor of Chemistry and Biochemistry at the University of Arkansas, USA. His research focuses on the development of novel analytical chemistry instrumentation and analysis paradigms.

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International Journal of Analytical Chemistry - Table of contents 2022

International Journal of Analytical Chemistry | Hindawi

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International Journal of Analytical Chemistry publishes research reporting new experimental results and chemical methods, especially in relation to important analytes, difficult matrices, and topical samples.

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International Journal of Analytical Chemistry

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