scholarly journals Improved mass spectrometric detection of acidic peptides by variations in the functional group pKa values of reverse micelle extraction agents

The Analyst ◽  
2018 ◽  
Vol 143 (6) ◽  
pp. 1434-1443 ◽  
Author(s):  
Bo Zhao ◽  
Mahalia A. C. Serrano ◽  
Meizhe Wang ◽  
Tianying Liu ◽  
Mallory R. Gordon ◽  
...  
Keyword(s):  
Functional Groups ◽  
Aqueous Phase ◽  
Isoelectric Point ◽  
Reverse Micelle ◽  
Reverse Micelles ◽  
Functional Group ◽  
Selective Extraction ◽  
Mass Spectrometric ◽  
Acidic Peptides ◽  
Reverse Micelle Extraction

Functional groups in reverse micelles maintain their aqueous phase pKa and allow selective extraction of peptides according to isoelectric point.

scholarly journals Reverse Micelle Liquid-Liquid Extraction of a Pharmaceutical Product

2012 ◽  
Vol 545 ◽  
pp. 240-244 ◽  
Author(s):  
Siti Hamidah Mohd-Setapar ◽  
Siti Norazimah Mohamad-Aziz ◽  
N.H. Harun ◽  
S.H. Hussin
Keyword(s):  
Aqueous Solution ◽  
Aqueous Phase ◽  
Reverse Micelle ◽  
Surfactant Concentration ◽  
Protein Extraction ◽  
Biological Activities ◽  
Extraction Process ◽  
Pharmaceutical Product ◽  
Penicillin G ◽  
Reverse Micelle Extraction

Reverse micelle extraction has received considerable attention in recent years due to its ability to selectively solubilise solutes from an aqueous phase, and in the case of biomolecules to maintain their biological activities. The apparent success of research on protein extraction from the aqueous phase using reverse micelle provides motivation to study the solubilisation of antibiotic. The objective of this study is to investigate the extraction of antibiotic (penicillin G is chosen as model antibiotic) from aqueous solution (forward extraction) and from the reverse micelle to a new aqueous solution (backward extraction). Sodium di(2-ethylhexyl)sulfosuccinate (AOT) is chosen as the surfactant and isooctane as the organic solvent. The UV-Vis spectrophotometer is used to determine the mass of penicillin G in solution after the extraction process. The extraction is expected to be influenced by the initial penicillin G concentration, the salt type and concentration in the aqueous phase, pH, and surfactant concentration. It is expected that as penicillin is an interfacially active compound that will interacts with AOT surfactant, the interfacial association will be dependent on both pH and surfactant concentration.

Assessment of micro-polarity anisotropy as a function of surfactant packing in sodium dodecyl sulphonate–hexane reverse micelles

Soft Matter ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 22-25 ◽  
Author(s):  
Xin Peng ◽  
Xing-Zhong Yuan ◽  
P. Somasundaran ◽  
Partha Patra
Keyword(s):  
Aqueous Phase ◽  
Reverse Micelle ◽  
Reverse Micelles ◽  
Sodium Dodecyl ◽  
Oil Water ◽  
Self Assembled

The micro-polarity anisotropy behaviour across the aqueous phase of a SDS (sodium dodecyl sulphonate)–hexane reverse micelle (RM) relies on the SDS packing in the oil–water interfacial self-assembled surfactant structure of the RM.

scholarly journals Resilience of Epiphytic Lichens to Combined Effects of Increasing Nitrogen and Solar Radiation

2021 ◽  
Vol 7 (5) ◽  
pp. 333
Author(s):  
Lourdes Morillas ◽  
Javier Roales ◽  
Cristina Cruz ◽  
Silvana Munzi
Keyword(s):  
Global Change ◽  
Solar Radiation ◽  
Functional Groups ◽  
Physiological Response ◽  
Functional Group ◽  
Environmental Drivers ◽  
Combined Effects ◽  
Environmental Stressor ◽  
Comprehensive Understanding ◽  
Direct Sunlight

Lichens are classified into different functional groups depending on their ecological and physiological response to a given environmental stressor. However, knowledge on lichen response to the synergistic effect of multiple environmental factors is extremely scarce, although vital to get a comprehensive understanding of the effects of global change. We exposed six lichen species belonging to different functional groups to the combined effects of two nitrogen (N) doses and direct sunlight involving both high temperatures and ultraviolet (UV) radiation for 58 days. Irrespective of their functional group, all species showed a homogenous response to N with cumulative, detrimental effects and an inability to recover following sunlight, UV exposure. Moreover, solar radiation made a tolerant species more prone to N pollution’s effects. Our results draw attention to the combined effects of global change and other environmental drivers on canopy defoliation and tree death, with consequences for the protection of ecosystems.

Selective Transport of Water-Soluble Proteins from Aqueous to Ionic Liquid Phase via a Temperature-Sensitive Phase Change of These Mixtures

2012 ◽  
Vol 65 (11) ◽  
pp. 1548 ◽  
Author(s):  
Yuki Kohno ◽  
Nobuhumi Nakamura ◽  
Hiroyuki Ohno
Keyword(s):  
Phase Change ◽  
Aqueous Phase ◽  
Selective Dissolution ◽  
Selective Extraction ◽  
Soluble Proteins ◽  
Water Soluble ◽  
Temperature Sensitive ◽  
Salting Out ◽  
Key Factor ◽  
The Difference

Mixtures of some ionic liquids (ILs) and water show reversible phase change between a homogeneous mixture and phase-separated state by a small change in temperature. Some water-soluble proteins have been migrated from the aqueous to the IL phase. When tetrabutylphosphonium 2,4,6-trimethylbenzenesulfonate was used as an IL, cytochrome c (Cyt.c) was found to be extracted from the water phase to the IL phase. Conversely, both horseradish peroxidase (HRP) and azurin remained in the aqueous phase. This selective extraction was comprehended to be due to the difference in solubility of these proteins in both phases. The separated aqueous phase contained a small amount of IL, which induced the salting-out of Cyt.c. On the other hand, condensed IL phase promoted the salting-in of Cyt.c. As a result, Cyt.c was preferably dissolved in the hydrated IL phase rather than aqueous phase. In the case of HRP, there was only a salting-out profile upon increasing the concentration of IL, which induced selective dissolution of HRP in the aqueous phase. These results clearly suggest that the profile of salting-out and salting-in for proteins is the key factor to facilitate the selective extraction of proteins from aqueous to the IL phase.

Utilization of green sophorolipids biosurfactant in reverse micelle extraction of antibiotics: Kinetic and mass transfer studies

2019 ◽  
Vol 276 ◽  
pp. 225-232 ◽  
Author(s):  
Sing Chuong Chuo ◽  
Akil Ahmad ◽  
Siti Hamidah Mohd-Setapar ◽  
Sarajul Fikri Mohamed ◽  
Mohd. Rafatullah
Keyword(s):  
Mass Transfer ◽  
Reverse Micelle ◽  
Mass Transfer Studies ◽  
Reverse Micelle Extraction

scholarly journals Food Additives Frequency in processed baby products in Cochabamba, Bolivia

2021 ◽  
Vol 17 (Especial) ◽  
pp. 19-27
Author(s):  
Nelcy Aguilar Sasari ◽  
Milenka Alessandra Fernández Ledezma ◽  
Tania Araujo-Burgos
Keyword(s):  
Shelf Life ◽  
Functional Groups ◽  
Frequency Analysis ◽  
Metropolitan Area ◽  
Sodium Nitrate ◽  
Functional Group ◽  
Food Additives ◽  
Processed Food ◽  
Food Labels ◽  
Organoleptic Properties

Additives are necessary substances to improve the nutritional and organoleptic properties and the shelf life of processed food. In addition, their use is regulated, and it must be declared on the food labels. Thus, the objective of this research was to determine the frequency of food additives in processed baby products in Cochabamba metropolitan area (Bolivia). Data were collected by label reading and a frequency analysis was performed by additives and by functional group. 26 baby products were found where 41 food additives were identified with an occurrence of 256 times, and a mean of 9,8 additives per product. Moreover, the functional groups most widely used are antioxidants and colorants. Finally, the most frequent additives are mostly harmless, except for sodium nitrate and copper sulfate.

scholarly journals Hydrophilic modification of polypropylene membranes and films by catalytic ozonation

2021 ◽  
Author(s):  
Hong Bin Gu
Keyword(s):  
Contact Angle ◽  
Functional Groups ◽  
Aqueous Phase ◽  
Gaseous Phase ◽  
Graft Polymerization ◽  
Copper Catalyst ◽  
Catalytic Ozonation ◽  
Sem Images ◽  
Hydrophilic Modification ◽  
Gaseous Media

Commercial polypropylene microfiltration membranes (PPMM) and biaxial oriented polypropylene (BOPP) films were ozonated in aqueous and gaseous media, respectively, followed by graft polymerization of acryl amide (AAm), hydroxyethyl methacrylate (HEMA), and polyethylene glycol (PEG) to improve their surface hydrophilicity. The efficiency of ozonation conducted in the gaseous and aqueous phases was compared, the gaseous phase ozonation was found slightly more effective in generating peroxide groups, while the aqueous phase ozonation was found more effective in grafting polymerization. Scavengers were added to the aqueous phase ozonation, results indicated that both the radical groups and the molecule ozone contributed to the peroxide generation. The free radical groups contributed maximum 25% and 32% for ozonation of PPMM and BOPP, respectively, and the molecule ozone contributed the percentage remaining. Results also showed that the concentration of peroxides generated on the surfaces of PPMM or BOPP increased with the applied ozone dose and ozonation time in both phases. Copper sulfate hydrate (CuSO4·5H2O) and ferric chloride hydrate (FeCl3·6H2O) were added in the aqueous phase ozonation as homogenous catalysts, results showed that the peroxide generation rate of PPMM and BOPP was improved comparing to that of ozonation without catalyst. The peroxide generation of PPMM showed 17% increase by adding copper catalyst, and 16% increase in peroxide generation was observed in ferric catalyzed ozonation of BOPP. The mechanism of the aqueous phase ozonation was investigated, along with that of catalytic ozonation. An enhanced radical process was found for catalytic ozonation in this study. The hydrophilicity of PPMM and BOPP was improved by graft polymerization of AAm, HEMA and PEG initiated by the peroxides. The aqueous phase ozonation was found more effective in grafting. A washing test was conducted using distilled water blending with 10% isopropyl alcohol. When the ozonated membranes and films were washed and compared to the non-washed ones, it was found that the gaseous phase ozonated PPMM or BOPP lost more peroxides than their aqueous phase counterpart after washing. The washing tests showed that the aqueous phase ozonation could induce a better graft polymerization, because part of the tested peroxides from the gaseous ozonation was washed away in the cleaning and grafting process. The improved hydrophilicity of PPMM was indicated by the contact angle reduction from 129° to 91° for AAm grafting; from 126° to 74° for HEMA grafting; and from 126° to 88° for PEG grafting; Fourier Transform Infrared (FTIR) measurements showed additional peaks of functional groups, such as amine (N-H) and amide (–N-C=O) functional groups from the grafted AAm (CH2=CH-CO-NH2); and the Scanning Electron Microscope (SEM) images confirmed amorphicity changes of the graft polymerization. X-ray Diffraction (XRD) diffractogram revealed the crystallinity changes of ozonated and grafted PPMM. Bovine serum albumin (BSA) was used to test the filtration performance of virgin and grafted membranes, the filtration tests demonstrated the improvement in anti-fouling effect of the modified PPMM; and the SEM images of the fouled and washed membranes revealed the pore blockage and recovering on the surface. The hydrophilicity of the grafted BOPP was also improved, indicated by the contact angle reduction of AAm grafted film from 80° to 56°. The FTIR showed additional peaks of N-H and –N-C=O functional groups of grafted AAm. SEM images indicated amorphicity changes of the graft polymerization. The film modified by the aqueous phase ozonation showed its advantages of better graft polymerization, hydrophilicity, and protein adsorption. The results of this study positively impacted the industrial using of PPMM to elongate its duration time of filtration, and improved the applications of BOPP in biomedical areas

scholarly journals Phytochemical Screening, Spectrum Profile of Functional Groups, and Effervescent Formulation of Kepok Banana Peels Stem Extract

2021 ◽  
Vol 4 (2) ◽  
pp. 66-72
Author(s):  
Robby Candra Purnama ◽  
Annisa Primadiamanti
Keyword(s):  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Secondary Metabolites ◽  
Functional Groups ◽  
Functional Group ◽  
Screening Method ◽  
Phytochemical Screening ◽  
Stem Extract ◽  
Group Profile ◽  
Banana Stem

Kepok banana plants contain secondary metabolites such as tannins and flavonoids. Tannins and flavonoids have various properties for human health. Research has been carried out to identify secondary metabolite compounds (tannins, flavonoids, and saponins) by using the phytochemical screening method to see the functional group profile contained in the extract of kepok banana stem waste. Kepok banana stem waste was extracted in 96% ethanol, then evaporated and screened phytochemically. This extract was used to prepare effervescently. Screening results showed that tannin and flavonoids were identified by the appearance of the following color black-green and dark red, respectively. Meanwhile, saponins were negative because the foam formed had a height of 0.3 cm and did not meet the saponins' positive requirements (1-3 cm high foam and stable for 5 minutes). Identification of functional groups in the extract of kepok banana stem waste using Fourier-transform Infrared Spectroscopy (FTIR) showed that C-C stretching in the area 2927.24 cm-1, O-H stretching in the 3423.87 cm-1 area, C=O stretching in the 1648.87 cm-1 area. Also appeared bending CH2 in the region of 1421.45 cm-1, and C-C in the area of 1149.98 cm-1. The characteristics of three different formulas (A, B, and C) of effervescent have been investigated: the moisture content of 2.51%; 2.55%, and 2.52%, respectively. Then, flow rate of 8.81 g/s; 8.83 g/s; and 8.82 g/s, compressibility of 14.5%; 14.4%; and 14.5%, and a pH of 5.97; 5.98; and 5.97 respectively. All parameters are eligible.

scholarly journals Functional Group Identification for FTIR Spectra Using Image-Based Machine Learning Models

2021 ◽  
Author(s):  
Abigail Enders ◽  
Nicole North ◽  
Chase Fensore ◽  
Juan Velez-Alvarez ◽  
Heather Allen
Keyword(s):  
Machine Learning ◽  
Gas Phase ◽  
Functional Groups ◽  
Functional Group ◽  
Spectroscopic Method ◽  
Group Identification ◽  
Spectroscopic Technique ◽  
Ftir Spectra ◽  
Spectral Interpretation ◽  
Time Required

<p>Fourier Transform Infrared Spectroscopy (FTIR) is a ubiquitous spectroscopic technique. Spectral interpretation is a time-consuming process, but it yields important information about functional groups present in compounds and in complex substances. We develop a generalizable model via a machine learning (ML) algorithm using Convolutional Neural Networks (CNNs) to identify the presence of functional groups in gas phase FTIR spectra. The ML models will reduce the amount of time required to analyze functional groups and facilitate interpretation of FTIR spectra. Through web scraping, we acquire intensity-frequency data from 8728 gas phase organic molecules within the NIST spectral database and transform the data into images. We successfully train models for 15 of the most common organic functional groups, which we then determine via identification from previously untrained spectra. These models serve to expand the application of FTIR measurements for facile analysis of organic samples. Our approach was done such that we have broad functional group models that inference in tandem to provide full interpretation of a spectrum. We present the first implementation of ML using image-based CNNs for predicting functional groups from a spectroscopic method.</p>

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