Flow gradient liquid chromatography using a coated anion exchange microcolumn

Amphoteric surfactants have long hydrophobic hydrocarbon chain and hydrophilic positive as well as negative charged center connected with each other by a spacer group. Thus, this type of surfactant maintains overall charged neutrality. The properties of amphoteric surfactants depend primarily on the length of the hydrophobic hydrocarbon chain, the number of methylene segments in the spacer, the positive and negative charged groups, and their relative position. The ionic activity of amphoteric surfactants is influenced according to the pH value of the solvent. They display cationic behavior below the isoelectric points and anionic behavior at a higher pH. They take the shape of zwitterions in the area of the isoelectric point. In fact, amphoteric surfactants can be parted into pH‐sensitive and pH‐insensitive surfactants. The pH‐insensitive surfactants stay as zwitterionic form irrespective of the pH of the solution. This surfactant has some unique features because of its precise molecular structure as follows: high water solubility, high surface activities, a wide isoelectric range, low critical micelle concentration (CMC), high foam stability, low toxicity, low irritating, excellent biodegradability, bioactivity, interface change, and so on. Because of these special characteristics, amphoteric surfactants have been immensely interested in many applications in the scientific community, including cosmetics, chromatography, enhanced oil recovery, electrochemistry, nanoscience, polymer chemistry, and waste water treatment. This review aims to study about amphoteric surfactants, which have only one hydrophobic hydrocarbon tail and two oppositely charged hydrophilic headgroups connected with each other by a spacer group and its properties, applications in various academics and industrial fields.

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“…3. Used in the amphoteric ion chromatography for charged molecules separation (Nesterenko et al, 2006).…”

Section: Electrochemistrymentioning

confidence: 99%

Properties and applications of amphoteric surfactant: A concise review

Sarkar

Pal

Rakshit

et al. 2021

J Surfact & Detergents

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“…www.jss-journal.com siderable effect upon the retention of anionic species [11,13]. The carboxylic acid group of DDMAU has a pK a value of l5.0.…”

Section: Mobile Phase Concentration and Phmentioning

confidence: 99%

“…The detailed coating procedure and the stability of the coating provided by this surfactant on various C 18 -modified stationary phases are described elsewhere [11]. The required amount of the surfactant was weighed out for a stock solution of 10 mM, dissolved in Milli-Q water and then filtered.…”

Section: Column Coatingmentioning

confidence: 99%

Separation of nucleic acid precursors on an amphoteric surfactant modified monolith using combined eluent flow, pH and concentration gradient

Nesterenko

Guivarc'h

Duffy

et al. 2007

J of Separation Science

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An RP monolithic column coated with an amphoteric carboxybetaine type surfactant has been used with a combined triple eluent concentration, pH and flow gradient ion chromatography technique for the simultaneous separation of up to 18 nucleotides, nucleosides and nucleobases. The separation of up to eight precursors on a 1 cm long monolithic microcolumn using the combined gradient approach is also shown. The method was applied to the separation of the above nucleic acid precursors in perchloric acid extracts of yeastolates samples.

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“…The most common way to tune the performance is gradual change in the composition of the mobile phase leading to gradient elution LC . Additionally, mobile phase flow rate and temperature can also be tuned . A continual change in experimental conditions requires more complex instrumentation.…”

Section: Introductionmentioning

confidence: 99%

Monolithic stationary phases with a longitudinal gradient of porosity

Urban

Hájek

Švec

2017

J of Separation Science

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The duration of the hypercrosslinking reaction has been used to control the extent of small pores formation in polymer-based monolithic stationary phases. Segments of five columns hypercrosslinked for 30-360 min were coupled via zero-volume unions to prepare columns with segmented porosity gradients. The steepness of the porosity gradient affected column efficiency, mass transfer resistance, and separation of both small-molecule alkylbenzenes and high-molar-mass polystyrene standards. In addition, the segmented column with the steepest porosity gradient was prepared as a single column with a continuous porosity gradient. The steepness of porosity gradient in this type column was tuned. Compared to a completely hypercrosslinked column, the column with the shallower gradient produced comparable size-exclusion separation of polystyrene standards but allowed higher column permeability. The completely hypercrosslinked column and the column with porosity gradient were successfully coupled in online two-dimensional liquid chromatography of polymers.

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Flow gradient liquid chromatography using a coated anion exchange microcolumn

Cited by 10 publications

References 20 publications

Properties and applications of amphoteric surfactant: A concise review

Properties and applications of amphoteric surfactant: A concise review

Separation of nucleic acid precursors on an amphoteric surfactant modified monolith using combined eluent flow, pH and concentration gradient

Monolithic stationary phases with a longitudinal gradient of porosity

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