Chromatography eluent

Liquid phase chromatography can use a supercritical fluid as an eluent. The solvent evaporates on leaving the column and allows detection by FID. At present, there are few instances in the petroleum industry using the supercritical fluid technique. 

This reversed-phase chromatography method was successfully used in a production-scale system to purify recombinant insulin. The insulin purified by reversed-phase chromatography has a biological potency equal to that obtained from a conventional system employing ion-exchange and size-exclusion chromatographies (14). The reversed-phase separation was, however, followed by a size-exclusion step to remove the acetonitrile eluent from the final product (12,14). 

Magnesium, calcium, barium, and strontium can also be deterrnined by ion chromatography with y -phenylenediamine in perchloric acid as the eluent. Ion chromatography by conductimetric detection has been described, and appHcations to environmental waters have been discussed (1,22—23). 

Ion chromatography can be used to determine chloride concentrations of 2—1000 ppb with a carbonate—bicarbonate eluent (23). Eluoride, nitrite, phosphate, bromide, nitrate, and sulfate do not interfere and can be measured simultaneously with a total analysis time of <30 min. 

An important publication by Kost et al. (63JGU525) on thin-layer chromatography (TLC) of pyrazoles contains a large collection of Rf values for 1 1 mixtures of petroleum ether-chloroform or benzene-chloroform as eluents and alumina as stationary phase. 1,3- and 1,5-disubstituted pyrazoles can be separated and identified by TLC (Rf l,3>i y 1,5). For another publication by the same authors on the chromatographic separation of the aminopyrazoles, see (63JGU2519). A-Unsubstituted pyrazoles move with difficulty and it is necessary to add acetone or methanol to the eluent mixture. Other convenient conditions for AH pyrazoles utilize silica gel and ethyl acetate saturated with water (a pentacyanoamine ferroate ammonium disodium salt solution can be used to visualize the pyrazoles). 

One of trends of development of thin-layer chromatography implies that replacement of aqueous-organic eluents by micellar surfactants solution. This is reduces the toxicity, flammability, environmental contamination and cost of the mobile phases, reduce sample prepar ation in some cases. 

Acenaphthene [83-32-9] M 154.2, m 94.0 . Crystd from EtOH. Purified by chromatography from CCI4 on alumina with benzene as eluent [McLaughlin and Zainal J Chem Soc 2485 I960]. 

Aminophenol [123-30-8] M 109.1, m 190 (under N2), pKj 5.38, pKj lO.4. Crystd from EtOH, then water, excluding oxygen. Can be sublimed at 110°/0.3mm. Has been purified by chromatography on alumina with a 1 4 (v/v) mixture of absolute EtOH7 benzene as eluent. 

Anthrarufin [l,5-dihydroxy-9,10-anthraquinone] [117-12-4] M 240.1, m 280 (dec), pKj 9.90, pK 11.05. Purified by column chromatography on silica gel with CHCl3/Et20 as eluent, followed by recrystn from acetone. Alternatively recrystd from glacial acetic acid [Flom and Barbara J Phys Chem 89 4489 1985]. 

Bismethylaminoanthraquinone (Disperse Blue 14) [2475-44-7] M 266.3, A,max 640 (594)nm. Purified by thin-layer chromatography on silica gel plates, using toluene/acetone (3.1) as eluent. The main band was scraped off and extracted with MeOH. The solvent was evapd and the dye was dried in a drying pistol [Land, McAlpine, Sinclair and Truscott J Chem Soc, Faraday Trans I 72 2091 7976]. 

Fluoranthene (ben2o[/,A ]fluorene) [206-44-0] M 202.3, m 110-111°. Purified by chromatography of CCI4 solns on alumina, with benzene as eluent. Crystd from EtOH, MeOH or benzene. Purified by zone melting. [Gorman et al. J Am Chem Soc 107 4404 1985.]... 

Triphenylbenzene [612-71-5] M 306.4, m 173-175 . Purified by chromatography on alumina using benzene or pet ether as eluents. 

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