In the course of a study of various procedures for the concentration and purification of urinary estrogens, the feasibility of the chromatographic technique seemed to warrant investigation. Chromatography has been employed to advantage in isolation procedures (l-3) for certain estrogens but no attempt has been made to utilize it in any quantitative procedure for estrone, estriol, and cY-estradi...

._----__-_--_-_-______--_----_--_-_----_--__--------_-Bl Introduction-__-____--_-_---_____---_--_---__-_--------_--------__ 1 Collection and handling of samples.-_-----_-__--__-------_-_---__--3 Electron-capture gas chromatographic method-___..---_---,______.___ 4 Apparatus.-__-__---_-----_------------_-------_-_-------__-__ 4 Reagents-_-____----_---______-_---_-_-_-_-_-_-___-_---_-----4 Proced...

Oxalic acid dihydrate as a green, mild and efficient catalyst for the one-pot three-component Biginelli synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives from the reaction between β-keto esters (methyl or ethyl acetoacetate), aromatic aldehyde (benzaldehye derivatives) and urea or thiourea under thermal and solvent-free conditions with excellent yields and short reaction time is st...

serum fatty acids on 30 healthy lranian women were detemined by a gas chromatographic method. oleic and stearic acids were used as standards. the mean values were myristic acid 5. 7% , palmitic acid 43% , palmitoleic acid 5.3% , stearic acid 8% , oleic acid 21. 3% and linleic acid 16.4% of total fatty acid serum contents.

A new procedure for the quantitation of C-21 ketosteroids using trifluoromethanesulfonic acid-catalyzed precolumn dansylation and coupled column liquid chromatographic separation, followed by postcolumn 1,1'-oxalyldiimidazole peroxyoxalate chemiluminescence detection is presented. In the simultaneous optimization of chromatographic resolution and chemiluminescence intensity, a coupled column ch...

Lipophilicity (logP) represents one of the most studied and most frequently used fundamental physicochemical properties. At present there are several possibilities for its quantitative expression and many of them stems from chromatographic experiments. Numerous attempts have been made to compare different computational methods, chromatographic methods vs. computational approaches, as well as ch...

An efficient and simple one-pot approach for the synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives using antimony trichloride (SbCl3) as a mild catalyst by means of three-component Biginelli reaction between β-keto esters, aldehyde derivatives and urea/thiourea under thermal and solvent-free conditions with excellent yields and short reaction times is reported. This m...

Chromatographic techniques have recently been introduced which provide new approaches to serum protein separation and characterization (1-4). Sober, Gutter, Wyckoff, and Peterson, using diethylaminoethyl (DEAE) cellulose, described the initial application of anion-exchange cellulose chromatography to the fractionation and identification of serum proteins (1, 2). Their study indicated the great ...

An improved four-stage isolation and purification procedure for preparing poplar isoplastocyanins is described in detail. Absorbance (UV-VIS) spectroscopy and isoelectric focusing (IEF) are used to determine the protein purity and identity. The present procedure increases twice the total plastocyanin (PC) yield. Four PC isoform fractions are consecutively isolated at the third chromatographic s...

A simple and rapid high-performance liquid chromatographic method has been developed for determination in human plasma of isepamicin (ISP), an aminoglycoside antibiotic agent. After protein precipitation and clean-up procedure to remove lipophilic contaminants, ISP is derivatized pre-column with 6-aminoquinolyl-N-hydroxysuccinimidyl-carbamate for fluorescence detection. Chromatographic separati...