Nonstructural Carbohydrates in Italian Ryegrass Determined by Liquid Chromatography

Creatinine determined by "high-performance" liquid chromatography.

We describe a "high-performance" liquid-chromatographic procedure for determination of creatinine in serum. Creatinine is separated from other species by cation-exchange chromatography. Absorbance of the creatinine in the eluate is monitored at 234 nm. Results from this procedure on sera correspond closely to those of a manual Jaffé-reaction procedure involving use of a protein-free filtrate wi...

Urinary free catecholamines determined by liquid chromatography--fluorometry.

Free norepinephrine, epinephrine, and dopamine are determined in urine after purification on a small ion-exchange column and concentration on alumina. The catecholamines are separated by reversed-phase ion-pair chromatography and are quantitated by measuring their native fluorescence (lambda ex 285 nm, lambda em 305 nm). The internal standard is dihydroxybenzylamine. Within-day CVs for the comp...

Plasma amino acids determined by liquid chromatography within 17 minutes.

We present an HPLC method for the determination of amino acids in plasma. The method is based on automated precolumn derivatization of amino acids with o-phthalaldehyde, separation of the derivatives by reversed-phase chromatography, and quantification by fluorescence detection. Complete separation was achieved within 12 min. Total analysis time, including derivatization, chromatography, and re...

Mitochondrial aspartate aminotransferase determined by "Fast Protein Liquid Chromatography".

We describe an improved separation of the isoenzymes of aspartate aminotransferase (EC 2.6.1.1), based on ion-exchange chromatography. Involving the "Fast Protein Liquid Chromatography" system (Pharmacia) with a MonoQ column, this rapid, reproducible method for quantifying the mitochondrial enzyme shows good resolution and sensitivity, and results correlate well with those by an established imm...

Nonstructural Carbohydrates in Cool-season Grasses