Biomedical subjects

J T Klein Elhorst

Publications and source records attributed to J T Klein Elhorst.

5 recordsLinked to original sources

PubMed1992

Liquid chromatographic estimation of tranylcypromine in human plasma.

A simple, selective and quantitative estimation of tranylcypromine using liquid chromatography and electrochemical detection with apomorphine as internal standard in human plasma is described. Sample preparation is done by liquid-liquid extraction. The absolute mean recovery of apomorphine is 95%, the recovery of tranylcypromine is 81%. This method gives a simple estimation method to assay plasma concentrations of tranylcypromine in the therapeutic range (5-200 ng/ml) with good reproducibility and linearity.

Aged↗

PubMed1991

Selective and quantitative isolation and determination of apomorphine in human plasma.

A simple extraction system for the selective and quantitative isolation of apomorphine from human plasma is described. Apomorphine and N-n-propylnorapomorphine were isolated by complex formation between a borate group and the diol group of the apomorphines in an alkaline medium, this in combination with ion-pair formation. The reproducibility and linearity of this extraction method combined with high-performance liquid chromatography with electrochemical detection is excellent. The absolute mean recovery of apomorphine was 100%, the recovery of N-n-propylnorapomorphine was 98%. The detection limit of apomorphine in human plasma in the described system is approximately 0.5 ng/ml.

Apomorphine↗

PubMed1987

Improved specificity of the PABA test with p-aminosalicylic acid (PAS).

Until now use of the PABA test together with [14C] PABA to calculate the PABA excretion index has probably been the best adaptation suggested to enhance the specificity of this non-invasive pancreatic function test. Drawbacks of the method are the application of radioactivity, the fact that children, pregnant women, and patients with renal insufficiency have to be excluded from the test, and the possible interference of drugs and isotopes. We propose simultaneous administration of p-aminosalicylic acid (PAS) in the PABA test and quantification of the urinary PABA and PAS excretion with liquid chromatography. Urinary PABA and PAS excretion in six hours are comparable (69.5 +/- 8.4% and 65.6 +/- 18.4% respectively in five healthy volunteers). Application of the PABA/PAS ratio was compared with the urinary PABA excretion in 21 normal controls, 38 patients with pancreatic disease, and 42 patients without pancreatic pathology. The PABA/PAS ratio and the per cent PABA excretion correlated very well in pancreatic patients: (PABA/PAS ratio) = 0.0149 (% PABA) + 0.052 (r = 0.902). Use of the PABA/PAS ratio enhanced the specificity of the test from 76 to 89%.

4-Aminobenzoic Acid↗

PubMed1977

Urinary oxalate estimation.

A method of estimating urinary oxalate is described. Impurities which might otherwise interfere with the estimation are removed by means of an ion-exchange resin. The oxalate is then reduced to glycolic acid, which forms a coloured compound with chromotropic acid. It can then be estimated colorimetrically. No special equipment is required, oxalate recovery is good, and the method is reproducible and precise.

Chromatography, Ion Exchange↗

PubMed1976

Oxalic acid determination in plasma.

A method is described for the estimation of oxalic acid in plasma. After removing interfering substances with an ion-exchange resin, oxalic acid is reduced to glycolic acid, which forms a coloured compound with chromotropic acid. No special equipment is required. A good recovery and precision are found.

Chromatography, Ion Exchange↗