Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1976-9-1
pubmed:abstractText
A gas chromatographic method is presented for the measurement of theophylline in serum. To serum samples containing the drug the internal standard, 3-isobutyl-l-methylxanthine, was added and the serum was saturated with ammonium carbonate. A mixture of isopropanol-chloroform (5:95) was used for extraction. The organic phase was filtered and evaporated. The residue, dissolved in chloroform, was extracted with sodium hydroxide. The basic solution was acidified, washed with hexane and reextracted with isopropanol-chloroform. The organic phase was dried with anhydrous sodium sulphate before evaporation. The sample was derivatized with n-Butyl-8 reagent. 85% of theophylline was recovered by extraction. 3-Isobutyl-l-methylxanthine was recovered with the same efficiency as theophylline and gas chromatographed well. The standard curve was linear between 1.0 and 50.0 mug/ml theophylline. No interference was encountered from normal serum constituents or methylxanthines such as caffeine, theobromine, or 3-methylxanthine. Serum samples were stared in the refrigerator for two weeks without significant loss of drug. The precision and accuracy of the method were good.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9673
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
121
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
263-8
pubmed:dateRevised
2010-8-26
pubmed:meshHeading
pubmed:year
1976
pubmed:articleTitle
Improved theophylline serum analysis by an appropriate internal standard for gas chromatography.
pubmed:publicationType
Journal Article