The aim was to determine the conjugated linoleic acids in beef with GC-FID. Perfect separation of all of the isomers cannot be achieved, though conjugated linoleic acid isomers proved to be separable from the other fatty acids that are present in beef in a significant amount related to conjugated linoleic acids. Lipid-extraction was carried out with n-hexane/i-propanol, giving 6.8 percent highe...

Urinary porphyrins are separated, according to number of carboxyl groups, in a system consisting of a mu-Bondapak C18 stationary phase and a mobile phase of methanol and aqueous sodium phosphate (pH 3.5) in a linear gradient. The specimen is prepared simply by adjusting the pH of a 5-mL sample to 2.0 and removing solids by centrifugation. The eluted porphyrins are measured fluorometrically. Nat...

Ion-exchange chromatographic analysis of peroxynitric acid (O2NOOH) was performed by combining an acidic eluate with an UV-vis detector and immersing the separation column in an ice-water bath. The decomposition behavior of peroxynitric acid in the solution was also studied using this system. The fraction for the peroxynitric acid peak was collected. Ion-exchange chromatographic analysis of thi...

A gel chromatographic analytical procedure using Bio-Gel A-OSm in 6 M guanidine HCl-0.1 M Z-mercaptoethanol has been developed and standardized. The procedure permits the molecular weight of peptides in the size range of 2 to 146 amino acids in length to be established from the distribution coefficient of the peptide on the gel column. This procedure has been applied to an analysis of the size ...

Monolithic supports are efficient stationary phases for most of the important chromatographic separation modes. They can be applied for the chromatographic separation of biomolecules, nanoparticles, proteins, peptides, nucleic acids and low molecular mass organic acids. At the industrial level, monolithic chromatography is frequently used for the purification of large plasmids and bacteriophage...

Aminoglycosides are antimicrobial agents used frequently in treatment of human and animal diseases caused by aerobic, gram-negative bacteria. Because of the toxicity of these compounds, considerable effort has been attributed to analysis of aminoglycoside content in drug preparations, in serum and urine specimen in therapeutic drug monitoring, and in edible animal tissues in residue control. Th...

A method for gas-liquid chromatographic separation and quantitation of urinary steroid metabolites is described. A normal reference range has been established and classic examples of urinary steroid profiles of the major steroid disorders are given.

Two-dimensional gas chromatography (GC×GC) plays a central role into the elucidation of complex samples. The automation of the identification of peak areas is of prime interest to obtain a fast and repeatable analysis of chromatograms. To determine the concentration of compounds or pseudo-compounds, templates of blobs are defined and superimposed on a reference chromatogram. The templates then ...