GAS–LIQUID CHROMATOGRAPHY OF TERPENES: PART III. THE USE OF OLEIC ACID ESTERS AS LIQUID PHASES

1961 ◽  
Vol 39 (6) ◽  
pp. 1190-1199 ◽  
Author(s):  
E. von Rudloff
Keyword(s):  
Liquid Phase ◽  
Rapeseed Oil ◽  
Hydroxyl Groups ◽  
Gas Liquid Chromatography ◽  
Retention Data ◽  
Geometrical Isomers ◽  
Potassium Oleate ◽  
Liquid Phases ◽  
Degree Of Separation ◽  
Poly Ethylene

The separation of several cyclic terpene hydrocarbons and some oxygenated derivatives was studied on a variety of triglyceride and dioleate ester columns. Use of rapeseed oil, partially hydrogenated rapeseed oil, olive oil, triolein, tristearin, methyl oleate, and potassium oleate as liquid phases led to the conclusion that the presence of an esterified mono-unsaturated long-chain acid is a desirable constituent of the liquid phase. Dioleate esters of 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and polyethylene glycol showed useful differences in the degree of separation of both terpene hydrocarbons and oxygenated derivatives. Ether linkages, as in the di- and poly-ethylene glycol ester, also were associated with favorable separations. When the liquid phase contained free hydroxyl groups, the degree of separation of hydrocarbons and ketones was in general less favorable. The spacing of the ester groups was found to have some effect on retention data. The separation of such critical pairs of isomers as tricyclene and α-pinene, α-fenchene and camphene, and also geometrical isomers of oxygenated derivatives is facilitated by use of several of these liquid phases.

THE SEPARATION OF SOME TERPENOID COMPOUNDS BY GAS–LIQUID CHROMATOGRAPHY

1960 ◽  
Vol 38 (5) ◽  
pp. 631-640 ◽  
Author(s):  
E. von Rudloff
Keyword(s):  
Liquid Chromatography ◽  
Polyethylene Glycol ◽  
Liquid Phase ◽  
Diatomaceous Earth ◽  
Solid Support ◽  
Gas Liquid Chromatography ◽  
Polyphenyl Ether ◽  
Liquid Phases ◽  
Degree Of Separation ◽  
Separation Of Mixtures

A study has been made of the degree of separation of mixtures of some terpene hydrocarbons, some of their oxygenated derivatives, two sesquiterpene alcohols, and three monophenols on a variety of columns. Temperature and sample size affected the degree of separation and the solid support Chromosorb W, a calcined diatomaceous earth, was found to combine the advantages of Celite and C-22 firebrick without causing decomposition of the sample at higher temperatures. When Craig polyesters were used as liquid phases, separations equal to those obtained on polyethylene glycol were realized with the added advantage that these produced columns which are stable at 190 to 220 °C. Consequently, sesquiterpene alcohols and monophenols were also separated successfully. Another useful liquid phase for both low and high temperatures was found in a meta-linked polyphenyl ether. Squalene was found to be an efficient liquid phase for the separation of terpene hydrocarbons at 130 °C and lower. The possible application of the present findings for preparative work is discussed.

Gas-liquid chromatography of undervatized drugs after chromatographic extraction from blood.

1979 ◽  
Vol 25 (12) ◽  
pp. 2020-2025 ◽  
Author(s):  
M Werner ◽  
R J Mohrbacher ◽  
C J Riendeau
Keyword(s):  
Liquid Chromatography ◽  
Liquid Phase ◽  
Gas Liquid Chromatography ◽  
Gastric Aspirate ◽  
Chemical Derivatization ◽  
Integrated Method ◽  
Relative Retention ◽  
Liquid Phases ◽  
Precision And Accuracy ◽  
Chromatographic Extraction

Abstract We have developed an integrated method that overcomes the two main procedural difficulties of gas-liquid chromatography, namely, solvent-solvent extraction and chemical derivatization. Drugs are extracted from serum by column chromatography on granular diatomaceous earth (kieselguhr). Subsequent gas-liquid chromatography of underivatized samples can be performed on either of two liquid phases. A mixed liquid phase, used for quantitative gas-chromatographic assay on patients with a known therapeutic regimen, has enabled quantitation of 12 drugs in serum. Alternatively, a single liquid phase, used with the mixed liquid phase, permits the gas-chromatographic identification of unknown drugs on the basis of the characteristic pattern of the two relative retention times; by this approach more than 40 drugs have been identified in cases of suspected intoxication, both in serum and in gastric aspirate. Besides providing ease of performance and wide applicability, the proposed procedure offers a degree of precision and accuracy that compares favorably with established methods.

A neutralization charge detection method for detecting ions under ambient and liquid-phase conditions

2016 ◽  
Vol 52 (29) ◽  
pp. 5187-5189 ◽  
Author(s):  
Ko-Keng Chang ◽  
Yi-Hong Cai ◽  
Chung-Hsuan Chen ◽  
Yi-Sheng Wang
Keyword(s):  
Liquid Phase ◽  
Detection Method ◽  
Sensitive Detection ◽  
Charge Detection ◽  
Liquid Phases

A novel neutralization charge detection method enabling the fast and sensitive detection of ions under ambient and liquid phases.

scholarly journals The Intramolecular Pressure and the Extension of the Critical Point’s Influence Zone on the Order Parameter

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jose Luis Rivera ◽  
Homero Nicanor-Guzman ◽  
Roberto Guerra-Gonzalez
Keyword(s):  
Transition Temperature ◽  
Critical Temperature ◽  
Liquid Phase ◽  
Order Parameter ◽  
Bulk Liquid ◽  
Influence Zone ◽  
Molecular Potential ◽  
Liquid Phases ◽  
Dynamics Simulations ◽  
Wide Zone

The critical point affects the coexistence behavior of the vapor-liquid equilibrium densities. The length of the critical influence zone is under debate because for some properties, like shear viscosity, the extension is only a few degrees, while for others, such as the density order parameter, the critical influence zone covers up to hundreds of degrees below the critical temperature. Here we show that, for ethane, the experimental critical influence zone covers a wide zone of tens of degrees (below the critical temperature) down to a transition temperature, at which the apparent critical influence zone vanishes, and the transition temperature can be predicted through a pressure analysis of the coexisting bulk liquid phase, using a simple molecular potential. The liquid phases within the apparent critical influence zone show low densities, making them behave internally like their corresponding vapor phases. Therefore, Molecular Dynamics simulations reveal that the experimentally observed wide extension of the critical influence zone is the result of a vapor-like effect due to low bulk liquid phase densities.

Collision induced microwave absorption in N2, CH4, and CF4 in the gaseous and liquid phases

1977 ◽  
Vol 55 (6) ◽  
pp. 496-505 ◽  
Author(s):  
J. L. Urbaniak ◽  
I. R. Dagg ◽  
G. E. Reesor
Keyword(s):  
Liquid Phase ◽  
Microwave Absorption ◽  
Low Density ◽  
Temperature Range ◽  
Liquid Phases ◽  
Gas To Liquid

Measurements of collision induced microwave absorption at 2.3 cm−1 have been carried out on gaseous N2 in the temperature range from 124 to 156 K and on liquid N2 in the temperature range from 77 to 125 K. The low density gaseous measurements have been found to agree well with the previous microwave and infrared results and with existing theories. The dependence of the absorption on density has been obtained at 156 K up to a density of 400 amagat and the results compared with the absorption in the liquid at the same density. The absorption is found to be a function of temperature and density but does not depend on the molecules being in a gas or liquid phase. Results for liquid CH4 and CF4 are reported and compared with previous microwave gaseous results. In contrast to the results for N2 the dependence on the square of the density changes by a relatively small amount in going from the low density gas to liquid densities.

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