Publications by authors named "Noor Abdulhussain"

5 Publications

  • Page 1 of 1

Fabrication of monolithic frits and columns for chip-based multidimensional separation devices.

J Sep Sci 2022 Jan 23. Epub 2022 Jan 23.

Van 't Hoff Institute for Molecular Science (HIMS), University of Amsterdam, Amsterdam, the Netherlands.

In this work, devices for two-dimensional separations are considered. The device contains a flow distributor, a first-dimension channel, and 17 second-dimension outlets. In the design, all connections between the first-dimension channel, the flow distributor, and the second-dimension outlets were tapered, with a minimal diameter of 20 μm. The use of photo-masking is explored for the fabrication of monolithic frits in all tapered connections. Monolithic frits with optimized permeability and length were successfully fabricated in all 33 tapered channels through light-induced polymerization, photo-masking, and selective exposure. The efficacy of the monolithic frits was demonstrated by creating a packed bed of 15-μm particles, confined within the first-dimension channel. The outlet of the first-dimension channel was successfully connected to a mass spectrometer. Effective flow confinement was demonstrated with a reversed-phase separation of a mixture of five standard peptides. This article is protected by copyright. All rights reserved.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jssc.202100901DOI Listing
January 2022

Latest Trends on the Future of Three-Dimensional Separations in Chromatography.

Chem Rev 2021 Oct 20;121(19):12016-12034. Epub 2021 Apr 20.

Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park, 1098 XH, Amsterdam, The Netherlands.

Separation and characterization of complex mixtures are of crucial importance in many fields, where extremely high separation power is required. Three-dimensional separation techniques can offer a path toward achieving high peak capacities. In this Review, online three-dimensional separation systems are discussed, including three-dimensional gas chromatography, and hyphenated combinations of two-dimensional gas chromatography with liquid chromatography or supercritical-fluid chromatography. Online comprehensive two-dimensional liquid chromatography provides detailed information on complex samples and the need for higher peak capacities is pushing researchers toward online three-dimensional liquid chromatography. In this review, an overview of the various combinations are provided and we discuss and compare their potential performance, advantages, perspectives, and results obtained during the most recent 10-15 years. Finally, the Review will discuss a novel approach of spatial three-dimensional liquid separation to increase peak capacity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.chemrev.0c01244DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8517953PMC
October 2021

Fabrication of polymer monoliths within the confines of non-transparent 3D-printed polymer housings.

J Chromatogr A 2020 Jul 12;1623:461159. Epub 2020 May 12.

Van't Hoff Institute for Molecular Sciences, Science Park, University of Amsterdam 1098 HX Amsterdam, Netherlands; The Centre for Analytical Sciences Amsterdam (CASA), University of Amsterdam 1098 HX Amsterdam, Netherlands.

In the last decade, 3D-printing has emerged as a promising enabling technology in the field of analytical chemistry. Fused-deposition modelling (FDM) is a popular, low-cost and widely accessible technique. In this study, RPLC separations are achieved by in-situ fabrication of porous polymer monoliths, directly within the 3D-printed channels. Thermal polymerization was employed for the fabrication of monolithic columns in optically non-transparent column housings, 3D-printed using two different polypropylene materials. Both acrylate-based and polystyrene-based monoliths were created. Two approaches were used for monolith fabrication, viz. (i) in standard polypropylene (PP) a two-step process was developed, with a radical initiated wall-modification step 2,2'-azobis(2-methylpropionitrile) (AIBN) as the initiator, followed by a polymerization step to generate the monolith; (ii) for glass-reinforced PP (GPP) a silanization step or wall modification preceded the polymerization reaction. The success of wall attachment and the morphology of the monoliths were studied using scanning electron microscopy (SEM), and the permeability of the columns was studied in flow experiments. In both types of housings polystyrene-divinylbenzene (PS-DVB) monoliths were successfully fabricated with good wall attachment. Within the glass-reinforced polypropylene (GPP) printed housing, SEM pictures showed a radially homogenous monolithic structure. The feasibility of performing liquid-chromatographic separations in 3D-printed channels was demonstrated.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.chroma.2020.461159DOI Listing
July 2020

Analysis of charged acrylic particles by on-line comprehensive two-dimensional liquid chromatography and automated data-processing.

Anal Chim Acta 2019 Apr 9;1054:184-192. Epub 2019 Jan 9.

University of Amsterdam, van 't Hoff Institute for Molecular Sciences, Analytical-Chemistry Group, Science Park 904, 1098 XH, Amsterdam, the Netherlands.

A thorough understanding of particle formation and polymer growth during emulsion polymerization is indispensable for the development of particles and products with very specific properties. This has created a demand for the detailed characterization of various properties and property distributions - and the relation between these. A method is described that enables comprehensive, simultaneous determination of the size distribution of nanoparticles and the molecular-weight distribution of the constituting polymers as a function of the particle size. The result is a complete two-dimensional distribution that details the interdependence of the two parameters. The approach comprehensively combines hydrodynamic chromatography with size-exclusion chromatography. An automated band-broadening filter has been developed to improve the accuracy of the measured distributions. The algorithm utilizes automated curve-fitting approaches to describe detected particle distributions for each horizontal slice of the 2D-LC chromatogram, and filters band broadening using calibration curves. The method has been applied to samples of complex nanoparticles comprising hydrophobic, hydrophilic and charged moieties, viz. stabilized dispersions of poly[(methyl methacrylate)-co-(butyl acrylate)-co-(methacrylic acid)]-nanoparticles in water. We consistently found that, within a single population of particles, the weight-average molecular weight increases with particle size.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.aca.2018.12.059DOI Listing
April 2019

Nanoparticle Analysis by Online Comprehensive Two-Dimensional Liquid Chromatography combining Hydrodynamic Chromatography and Size-Exclusion Chromatography with Intermediate Sample Transformation.

Anal Chem 2017 09 8;89(17):9167-9174. Epub 2017 Aug 8.

Analytical-Chemistry Group, University of Amsterdam, van't Hoff Institute for Molecular Sciences , Science Park 904, 1098 XH Amsterdam, The Netherlands.

Polymeric nanoparticles have become indispensable in modern society with a wide array of applications ranging from waterborne coatings to drug-carrier-delivery systems. While a large range of techniques exist to determine a multitude of properties of these particles, relating physicochemical properties of the particle to the chemical structure of the intrinsic polymers is still challenging. A novel, highly orthogonal separation system based on comprehensive two-dimensional liquid chromatography (LC × LC) has been developed. The system combines hydrodynamic chromatography (HDC) in the first-dimension to separate the particles based on their size, with ultrahigh-performance size-exclusion chromatography (SEC) in the second dimension to separate the constituting polymer molecules according to their hydrodynamic radius for each of 80 to 100 separated fractions. A chip-based mixer is incorporated to transform the sample by dissolving the separated nanoparticles from the first-dimension online in tetrahydrofuran. The polymer bands are then focused using stationary-phase-assisted modulation to enhance sensitivity, and the water from the first-dimension eluent is largely eliminated to allow interaction-free SEC. Using the developed system, the combined two-dimensional distribution of the particle-size and the molecular-size of a mixture of various polystyrene (PS) and polyacrylate (PACR) nanoparticles has been obtained within 60 min.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.analchem.7b01906DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5588091PMC
September 2017
-->