Year: 1965
Type: article
Abstract: Barbiturates can be separated rapidly and easily by thin-layer chromatography (Sunshine, 1963).Slow, intermediate, and fast acting barbiturates have respect- ively low, intermediate, and high Rf values.The inter- mediate group contains many of the drugs encountered in cases of overdose and identification of the actual barbiturate concerned may be impossible because of the closely similar Rf values of this group.Jackson (1960) described treatment with hot sulphuric acid before paper chromatography to distinguish between barbiturates of similar chromatographic mobility.The inert nature of the silica gel supporting medium used in thin-layer separations enables this acid treatment to be carried out directly on the plate with consequent convenience and saving of time.METHOD Chromatography is carried out by the method of Sunshine (1963), using 10 x 20 cm.glass plates (24 oz.glass) coated with a 250.layer of silica gel G (Merck).The developing solvent is chloroform-acetone (9:1).The tank should be the smallest that will accommodate the plate since failure to saturate the vapour phase results in high Rf values and poor separation.STANDARD SOLUTIONS Stock 1 % standard solutions are prepared in chloroform and keep at least three months at 5°C.A composite standard containing phenobarbitone, butobarbitone, pentobarbitone, quinalbarbitone, and hexobarbitone each at a concentration of 0-1 % is prepared by pooling 1 volume of each of the stock standards, evaporating to dryness and dissolving the residue in 10 volumes of 80% ethanol.
Source: Journal of Clinical Pathology
DOI: 10.1136/jcp.18.4.482
Authors: W. H. C. Walker, J. K. Wood
Institutions: Manchester Royal Infirmary, Bristol Royal Infirmary
Language: English
Subfield: Toxicology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2002294545