A variety of brush-type chiral stationary phases (CSPs) were developed using superficially porous particles (SPPs). Given their high efficiencies and relatively low back pressures, columns containing these particularly advantageous for ultrafast "chiral" separations in the 4-40 s range. Further, they used all mobile phase modes with flow rates pressures to separate over 60 pairs enantiomers. When operating under conditions, both instrumentation column packing must be modified or optimized so...

Sub-second liquid chromatography in very short packed beds is demonstrated as a broad proof of concept for chiral, achiral, and HILIC separations biologically important molecules. Superficially porous particles (SPP, 2.7 μm) different surface chemistries, namely, teicoplanin, cyclofructan, silica, quinine, were 0.5-cm-long columns separating classes compounds. Several issues must be addressed to obtain the maximum performance 0.5 cm with reduced plate heights 2.6 3.0. Modified UHPLC hardware...

New stationary phases are continuously developed for achieving higher efficiencies and unique selectivities. The performance of any new phase can only be assessed when the columns effectively packed under high pressure to achieve a stable bed. science packing with is one most crucial steps consistent reproducible high-resolution separations. A poorly column produce non-Gaussian peak shapes lower detection sensitivities. Given ever larger number phases, it impossible arrive at single...

The virtue of chemical sensors is speed and analyte specificity. response time to generate an analytical signal typically varies from ∼1 20 s, they are generally limited a single analyte. Chemical significantly affected by multiple interferents, matrix effects, temperature, can vary widely in sensitivity depending on the sensor format. Separation-based analyses remove effects interferents compatible with analytes. However, such has not been commensurate traditional until now. Beds very small...

More than 40 cosolvents have been used with carbon dioxide to alter its solvation strength. Among the most interesting systems is subcritical/supercritical CO2/alkanol eluents. Using small amounts of water in CO2/MeOH known be beneficial chiral chromatography. However, ramifications introducing as a cosolvent component not entirely understood. In this work, we demonstrate important aspects CO2/MeOH/H2O system on nine stationary phases very different surface chemistries, encompassing...

Using azeoptropic ‘190 proof’ ethanol eliminates the use of methanol in chiral super/subcritical fluid chromatography.

It is widely accepted that column technology ahead of existing chromatographic instruments. The output may not reflect the true picture peak profile inside column. instrumental optimization parameters become far more important when peaks elute in a few seconds. In this work, low viscosity advantage supercritical/subcritical CO2 coupled with high efficiency narrow particle size distribution silica. Using short efficient columns and flow rates (up to 19 mL/min), separations on order seconds...

With the introduction of ultrahigh efficiency columns and fast separations, need to eliminate peak deformation contributed by instrument must be effectively solved. Herein, we develop a robust framework automate deconvolution minimize its artifacts, such as negative dips, wild noise oscillations, ringing, combining regularized Perona–Malik (PM) anisotropic diffusion methods. A asymmetric generalized normal (AGN) function is proposed model instrumental response for first time. no-column data...

Stationary phases for hydrophilic interaction liquid chromatography (HILIC) are predominantly based on silica and polymer supports. We present porous graphitic carbon particles with covalently attached carboxylic acid groups (carboxylate-PGC) as a new HILIC stationary phase. PGC were modified by adsorbing the diazonium salt of 4-aminobenzoic onto PGC, followed reduction adsorbed sodium borohydride. The newly developed carboxylate-PGC phase exhibits different selectivity than that 35 HPLC...

Stationary phases composed of native cyclofructan 6 (CF6) and benzoic acid modified CF6 were synthesized evaluated for hydrophilic interaction liquid chromatography (HILIC).

Modern chromatographic data acquisition softwares often behave as black boxes where the researchers have little control over raw processing. One of significant interests separation scientists is to extract physico-chemical information from experiments and peak parameters. In addition, column developers need total shape analysis characterize flow profile in beds. Statistical moments offer a robust approach for providing detailed peaks terms area, its center gravity, variance, resolution, skew...

Analytical and preparative separation techniques, although perceived as less detrimental compared to industrial manufacturing processes, present a substantial concealed environmental threat.

ABSTRACT In experimental separations, the acquired signal can have four common but unwanted elements: (i) high‐frequency noise, (ii) drift, (iii) occasional periodic and pink (iv) a mixture of components traveling with close velocities. Additionally, separation scientists observe partially resolved peaks in chromatographic or capillary electrophoresis detector output. A protocol for digitally recovering “true data” is provided clear‐cut details open‐access codes formulating denoising,...

Abstract BACKGROUND: The fruit of date palm is consumed as an ideal high‐energy food. It also used for the treatment colds, fever, liver and abdominal troubles. Its nutritional composition strongly depends upon variety ripening stage. A number varieties are available in Pakistan but little known about their characteristics. Inherent moisture, volatile matter, ash, fixed carbon, sugar mineral metals seven commercial (Aseel, Basra, Begun, Janshoor, Mazoee, Rabee Zaidi) were investigated....

A significant number of published databases and research papers exist in foreign languages remain untranslated to date. Important sources primary scientific information German are Beilstein Handbuch der Organischen Chemie, Gmelin Anorganischen Landolt-Börnstein Zahlenwerte und Funktionen, Houben-Weyl Methoden fundamental papers, patents. Although Reaxys has acquired Gmelin, many original references still since 1770s, the presented printed online versions is often not duplicated. To read...

α-[(6-O-β-d-Glucopyranosyl-β-d-glucopyranosyl)oxy]-(αR)-benzeneacetonitrile, or R-amygdalin, is the most common cyanogenic glycoside found in seeds and kernels of Rosaceae family other plant genera such as Passiflora. Many commercially important are analyzed for amygdalin content. In "alternative medicine", has been sold a treatment cancer several decades without any rigorous scientific support its efficacy. We have that there some inconsistencies possible problems published analytical...