One-Minute High-Performance Liquid Chromatography Assay for 5′-Nucleotidase Using a 20-mm Reverse-Phase Column

Abstract Furfural (2-Jfuraldehyde) and hydroxymethylfurfural (S-hydroxy-2-furaIdehyde, HMF) are determined in brandy and honey by reverse phase high performance liquid chromatography. Brandies and other spirits are injected without sample preparation; honey is diluted with water and the solution is filtered before injection onto a reverse phase column with detection at 285 nm. The mobile phase is methanol–water (10+90) and the effluent flow rate is maintained at 1.0 mL/min. External standardization is used for quantitative determination. Recoveries from cognac and honey spiked at different levels ranged from 95 to 99% (furfural) and 95 to 100% (HMF). The furfural content of the brandies was also determined by the existing colorimetric method of the Bureau National Interprofessionel du Cognac. The HMF content of the honey was correlated to the results of the classic method of Winkler.

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Respiratory alkalosis does not alter NOx concentrations in human plasma and erythrocytes

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.2001.281.6.h2757 ◽

2001 ◽

Vol 281 (6) ◽

pp. H2757-H2761 ◽

Cited By ~ 16

Author(s):

Takaharu Ishibashi ◽

Kaname Kubota ◽

Mariko Himeno ◽

Taku Matsubara ◽

Tomoyuki Hori ◽

...

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Whole Blood ◽

Blood Cells ◽

High Performance ◽

Respiratory Alkalosis ◽

High Accuracy ◽

Reverse Phase ◽

Phase Column

To test the hypothesis that NOx (NO[Formula: see text] and NO[Formula: see text], metabolites of NO) accumulates in red blood cells (RBC) in response to changes in Pco 2 and bicarbonate (HCO[Formula: see text]) concentration in blood, we examined the effect of changes in Pco 2 and HCO[Formula: see text] induced by hyperventilation in healthy adults on partitioning of NOx in whole blood. NOx in hemolysate was measured by a high-performance liquid chromatography-Griess system equipped with a C18 reverse phase column to trap hemoglobin, which enables determination of whole blood NOx concentration and calculation of NOx concentration in RBC with high accuracy and reproducibility. NOx concentration in RBC was lower than that in plasma, and equilibrium between plasma and RBC was achieved rapidly after addition of NO[Formula: see text]. Changes in Pco 2 and HCO[Formula: see text] by hyperventilation failed to influence NOx concentrations in both plasma and RBC. Plasma NOx concentrations correlated with whole blood NOx and RBC NOx concentrations. Our results indicate that changes in Pco 2 or HCO[Formula: see text] induced by hyperventilation do not influence NOx compartmentalization in plasma and RBC.

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Analysis for indole compounds in urine by high-performance liquid chromatography with fluorometric detection.

Clinical Chemistry ◽

10.1093/clinchem/22.2.184 ◽

1976 ◽

Vol 22 (2) ◽

pp. 184-187 ◽

Cited By ~ 50

Author(s):

A P Graffeo ◽

B L Karger

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Fluorescence Detection ◽

Mobile Phase ◽

High Performance ◽

Fluorometric Detection ◽

Chromatographic System ◽

Reverse Phase ◽

Indole Compounds ◽

Phase Column

Abstract We describe a chromatographic system involving a high-performance chemically-bonded reverse-phase column and fluorescence detection for measurement of indoles in urine. We controlled retention and selectivity by optimizing the methanol content and pH of the mobile phase. Six reference indoles were separated in less than 20 min; three 5-hydroxyindoles were eluted in less than 7 min. About 5-15 ng of aqueous solutions of these compounds can be detected. The combination of selectivity (from use of the chromatographic column) and fluorescence detection permitted analysis for five of the six indoles after a single urine-deproteinization step.

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