0000000000171806
AUTHOR
K. K. Unger
Fast Response Heating Module for Temperature Programmed GC Analysis in Microreaction Systems
For monitoring the reactant and product concentrations of a gas phase microreactor for ethylene oxide synthesis the development of a miniaturised device for fast GC analysis suitable for operation in conjunction with the microreactor is advantageous. Therefore, a method employing short (0.2 – 0.4 m) packed capillary columns was developed. Highly crosslinked polystyrene microspheres proved to be the most suitable adsorbent enabling a high separation efficiency. For fast temperature programming design concepts for an efficient heating module capable to be used with short capillary columns were developed. In principle, planar as well as cylindrical designs are suitable for integration of a res…
Investigation of surface properties of lunar regolith: Part I
This paper describes an initial investigation of the surface properties of three lunar soil samples from the Apollo 11, 12 and 16 missions, respectively. We report on density measurements using a helium pycnometer, adsorption isotherms of krypton applied for the determination of specific surface area of the samples and gravimetric measurement of the isotherms of water, heptane and octane. Electron-microscopic photographs are described and discussed.
Prospects for Carbon as Packing Material in High-Performance Liquid Chromatography
Abstract Early work on use of carbons for liquid chromatography shows that special carbons must be developed if carbon is to be useful in HPLC. The processes used to make carbons, the properties of such carbons and the requirements for HPLC carbons are discussed. The preparation of HPLC carbons is reviewed in detail and the results which have been obtained are assessed in terms of their kinetic and thermodynamic performance. Applications are reviewed.
Determination of Phenols from Automobile Exhaust by Means of High-Performance Liquid Chromatography (HPLC)
Abstract The paper describes a procedure to determine ten representative phenols (phenol, m-, p-, o-cresol, 2,4-, 2,6-, 3,4-, 3,5-xylenol, 2,3,6-, 2,4,6-trimethylphenol) in engine exhaust. Sampling was performed by a conventional Grimmer device. A sample of the water condensate collected was extracted with ether. After concentration of the ether extract phenols were isolated from other interfering compounds by stepwise elution on a Lobar column packed with LiChroprep Si 60 under controlled conditions. Relative recovery of the majority of reference phenols ranged from 90-100%. Separation of phenols into individual components was performed on polar packings as well as on Reverse Phase packing…