Monolithic columns in high-performance liquid chromatography.

Monolithic silica columns for high-efficiency chromatographic separations

Capillary columns with in situ formed porous monolithic packing for micro high-performance liquid chromatography and capillary electrochromatography

The recent invention and successive commercial introduction of monolithic silica columns has motivated many scientists from both academia and industry to study their use in HPLC. The first paper on monolithic silica columns appeared in 1996. Currently about 200 papers have been published relating to applications and characterization of monolithic silica columns, including monolithic capillaries. This review attempts to give an overview covering various aspects of this new column type in the field of high throughput analysis of drugs and metabolites, chiral separations, analysis of pollutants and food-relevant compounds, as well as in bioanalytical separations such as in proteomics. Some of the applications are described in greater detail. The numerous publications dealing with the physicochemical and chromatographic characterization of monolithic silica columns are briefly summarized.

Applications of silica-based monolithic HPLC columns

Monolithic stationary phases for liquid chromatography and capillary electrochromatography.

Barium titanate (BaTiO3) powders of varying particle sizes were grown under hydrothermal conditions at a temperature of 240 °C. This was accomplished by varying the hydroxide concentration of the r...

Characterization of Submicron Particles of Tetragonal BaTiO3

Sintered octadecylsilica as monolithic column packing in capillary electrochromatography and micro high-performance liquid chromatography

Hydrothermal synthesis of barium titanate (BaTiO{sub 3}) at 240{degrees}C using different barium salts as starting reactants is examined. It is found that halide salts (I{sup {minus}}, Br{sup {minus}}, Cl{sup {minus}}) result in the highest tetragonal content, followed by acetate, nitrate, and hydroxide salts. The tetragonal content was quantified from differential scanning calorimetry by following the endothermic Curie transition around 130{degrees}C and reached as high as 37-39% for the materials made with the barium halides. The particle sizes ranged from 0.15 to 0.37 {mu}m, as estimated by scanning electron microscopy. Sintering and dielectric properties of the barium titanates synthesized from different barium sources were examined. BaTiO{sub 3} made from the chloride salt sintered with high densities at 1250{degrees}C with grain sizes of 1-5 {mu}m and a room-temperature dielectric constant (1 kHz) of 2960. 35 refs., 10 figs., 1 tab.

Hydrothermal Synthesis and Dielectric Properties of Tetragonal BaTiO3

Dynamics of capillary electrochromatography. II. Comparison of column efficiency parameters in microscale high-performance liquid chromatography and capillary electrochromatography.

The sintering behavior of hydrothermally synthesized cubic and tetragonal BaTiO3 powders was studied as a function of temperature In addition, the dielectric properties of the sintered samples were examined from room temperature to 200°C at a frequency of 1 kHz The influence of powder characteristics and sintering temperature on the microstructure development and dielectric properties were investigated It was found that tetragonal powders showed limited grain growth and higher final density upon sintering, whereas the cubic powder exhibited abnormal grain growth and lower density This was attributed to more disperse and homogeneous particles in the tetragonal powders with fewer defects, as compared to the cubic powder Correlations between the microstructure and the dielectric properties were developed As expected, samples with finer grain size and higher density exhibited higher dielectric constant and lower loss

https://iopscience.iop.org/article/10.1143/JJAP.36.214/pdf

Reza Asiaie

Papers

Characterization of Submicron Particles of Tetragonal BaTiO3

Sintered octadecylsilica as monolithic column packing in capillary electrochromatography and micro high-performance liquid chromatography

Hydrothermal Synthesis and Dielectric Properties of Tetragonal BaTiO3

Dynamics of capillary electrochromatography. II. Comparison of column efficiency parameters in microscale high-performance liquid chromatography and capillary electrochromatography.

Sintering and Dielectric Properties of Hydrothermally Synthesized Cubic and Tetragonal BaTiO3 Powders