Linked Life Data

8653202

Source:http://linkedlifedata.com/resource/pubmed/id/8653202

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1996-7-30
pubmed:abstractText
A synthetic mixture containing mainly 4'-bromo-4,5,6,7-tetrachlorofluorescein (4'BrTCF, ca. 25% by high-performance liquid chromatography) was prepared by direct bromination of tetrachlorofluorescein in ethanol. The 4'BrTCF was isolated and purified by pH-zone-refining counter-current chromatography (CCC), using two different two-phase solvent systems: diethyl ether-acetonitrile-water (4:1:5,v/v) and ter.-butyl methyl ether-water (1:1,v/v). For each system, the upper organic phase was acidified and used as the stationary phase and the lower aqueous phase was made basic and used as the mobile phase. pH-Zone-refining CCC of two 5-g batches of the crude mixture yielded 1.65 g of 4'BrTCF that was ca. 95% pure by HPLC. For these separations, a commercial counter-current chromatograph was fitted with a pH electrode in a flow cell to record the pH of the effluent "on line,' thereby replacing the tedious and time-consuming manual measurement of the pH of each fraction. Additionally, UV spectra of the effluent were continuously monitored and stored by using a computerized scanning UV-Vis detector equipped with an adjustable short-pathlength flow cell.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9673
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
732
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
283-90
pubmed:dateRevised
2009-1-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Isolation of 4'-bromo-4,5,6,7-tetrachlorofluorescein from a synthetic mixture by pH-zone-refining counter-current chromatography with continuous pH monitoring.
pubmed:affiliation
Office of Cosmetics and Colors, US Food and Drug Administration, Washington, DC 20204, USA.
pubmed:publicationType
Journal Article