The successful off-line coupling of asymmetrical flow field flow fractionation (AF4) and capillary electrophoresis (CE) for separation of nanoparticles (NPs) with different surface coatings was shown. We could successfully demonstrate that, in a certain NP size range, hyphenation of both techniques significantly improved the separation of differently coated NPs. Three mixtures of polystyrene nanoparticles (PS-NPs) with comparable core sizes but different coatings (no coating/carboxyl-coated) were studied. Separation in either method resulted in non-baseline resolved or non-separated peaks. In contrast, two-dimensional off-line coupling of AF4 and CE resulted in clearly separated regions in their 2 D plots in case of 20 and 50 nm particle mixtures, whereas the 100 nm NP mixture could not be separated at all. Various factors affecting the separation like hydrodynamic diameter or SDS concentration were discussed.
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http://dx.doi.org/10.1016/j.chroma.2019.01.056 | DOI Listing |
Anal Methods
January 2025
Geology & Mineral Analysis & Test Research Centre of Guangxi Zhuang Autonomous Region, Nan Ning, 530023, Guangxi Zhuang Autonomous Region, China.
Anal Chem
November 2024
Biogeochemistry Research Center (BGC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka 2370061, Japan.
We developed a new method for stable carbon and nitrogen isotopic (δC and δN) analysis of underivatized amino acid (AA) enantiomers simultaneously, based on high-performance liquid chromatography (HPLC) separation and off-line isotopic measurement. l- and d-Enantiomers of each AA were isolated using a ReproSil Chiral-AA column, purified by wet chemical procedure, and analyzed for δC and δN values with a nanomol-scale elemental analyzer/isotope-ratio mass spectrometry (nano-EA/IRMS) system. We successfully achieved the separation of l- and d-enantiomers of 15 proteinogenous AAs, with all l-enantiomers eluting before respective d-enantiomers.
View Article and Find Full Text PDFMol Neurodegener
October 2024
Department of Biochemistry, School of Medicine, Emory School of Medicine, 505J Whitehead Biomedical Research Building, 615 Michael St, Atlanta, GA, 30322, USA.
Crit Rev Anal Chem
August 2024
Faculty of Natural Science, Department of Analytical Chemistry, Comenius University in Bratislava, Bratislava, Slovak Republic.
This review presents a critical examination of the interface for coupling high performance liquid chromatography (HPLC) with Fourier transform infrared spectrometry (FTIR) since 2010. This coupling offers a robust analytical approach characterized by exceptional chemical specificity and the capacity to analyze complex multi-component mixtures qualitatively and quantitatively with high sensitivity, particularly in low limit of detection ranges. This coupling enables the identification of individual components of a mixture by IR after their separation by HPLC, although challenges arise from the potential distortion of infrared spectra by mobile phase components.
View Article and Find Full Text PDFAnal Chim Acta
August 2024
University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, SI-1000, Ljubljana, Slovenia.
Solid-phase extraction (SPE) has gained an essential role in environmental analytical chemistry. Classic off-line SPE coupled with LC-MS/MS systems creates powerful analytical procedures for ultratrace analysis of contaminants of emerging concern (CECs) in water. But, being associated with tedious work and large consumption of materials, alternative SPE modes are becoming interesting.
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