Separation of superparamagnetic magnetite nanoparticles by capillary zone electrophoresis using non‐complexing and complexing electrolyte anions and tetramethylammonium as dispersing additive

Abstract

Separations of bare superparamagnetic magnetite nanoparticles (BSPMNPs, approx. 11 nm diameter) was performed using non-complexing (nitrate) and complexing (chloride, citrate and phosphate) electrolyte ions with additions of tetramethylammonium hydroxide (TMAOH), which is commonly applied to control the synthesis of stable iron oxides. The use of TMAOH as a background electrolyte (BGE) additive for capillary electrophoresis (CE) separations provided for the first time electropherograms of BSPMNPs exhibiting symmetrical and highly reproducible peaks, free of spurious spikes characteristic of nanoparticle clusters. Consequently, accurate determination of the electrophoretic effective mobility of BSPMNPs was possible, yielding a value of -3.345E-08 m V s (relative standard deviation (RSD) of 0.500%). The obtained mobilities of BSPMNPs in the presence of various electrolyte ions show that the degree of complexation with the surface of BSPMNPs follows the order chloride < citrate < phosphate, correlating with the stabilities of Fe(III) complexes with the respective anions. Finally, bare and carboxylated iron oxide nanoparticles were successfully separated in only 10 min using 10 mM Tris-nitrate containing 20 mM of TMAOH as electrolyte. Our findings show that simple and rapid CE experiments are an excellent tool to characterise and monitor properties and interactions of iron oxide nanoparticles with other molecules for surface modification purposes.

Size‐dependent electrophoretic migration and separation of water‐soluble gold nanoclusters by capillary electrophoresis

“…However, due to the increased repulsive force between the large negative charge on the inner wall surface of the capillary and the negative charge carried by the analyte, the adsorption of the analyte is reduced, and the resolution is improved. What's more, the increase of pH results in increased dissociation of ‘the last’ proton from the buffering phosphate (depending on the literature the pKa 3 is about 12.3–12.7) . In some publications the one can find that the mobility of Au NPs is dependent on the co‐ions in BGE .…”

“…Thus, the size separation and purification of AuNCs have received considerable attention in many fields recently. In the past, various options have been developed for the separation of AuNCs, such as size‐exclusion chromatography (SEC) , gas chromatography , high performance liquid chromatography (HPLC) and capillary electrophoresis (CE) . Regarding AuNCs, there is a high level of requirements for resolution and theoretical plate count due to their separation according to their size and shape .…”

STability and Shelf-Life of Plasma Bubbling Treated Cow Milk

“…After giving plasma bubbling treatment to the milk sample, the pH was measured and compared with the control, boiled, commercialized (UHT and pasteurised) milk using the pH meter (Laqua, Horiba Scientific, Singapore) at ambient temperature (Alves et al ., 2018) for the detection of changes in the concentration of hydrogen in the sample.…”

Red Flags and Adversities on the Way to the Robust CE-ICP-MS/MS Quantitative Monitoring of Self-Synthesized Magnetic Iron Oxide(II, III)-Based Nanoparticle Interactions with Human Serum Proteins

“…Among separation techniques commonly coupled with ICP-MS/MS, capillary electrophoresis appears to be a cutting-edge alternative to high-pressure liquid chromatography (HPLC) due to lower sample consumption and higher resolution. There are a few examples of CE applications to determine differently modified SPIONs [ 23 , 24 , 25 ], but in the case of biological matrices and human serum samples, mainly other nanomaterials have been tested till now [ 26 , 27 , 28 ].…”