Roland Helger

Evaluation of column extraction: a new procedure for the analysis of drugs in body fluids.

A method is described for the extraction of drugs from body fluids, whereby liquid-liquid extraction is replaced by liquid-solid elution. The aqueous sample is absorbed on a column filled with dry supporting material. By elution with organic solvents lipophilic substances are extracted from the water phase which remains on the column. The eluate containing the drugs is free of emulsions. For optimal extraction any pH value and a variety of solvents can be used. Column extraction of urine, serum and blood is easily performed and gives high recovery rates, which are superior to conventional extraction. Thin layer chromatography of drugs following conventional XAD-2 and column extraction, demonstrates identical qualitative results, but shows higher purity of the column extracts. The sensitivity of detection is enhanced.

Thin layer chromatographic screening test for amino acid anomalies in urine without desalting using internal standards

Abstract A two dimensional thin layer Chromatographic method for screening of urine samples for amino acid anomalies is described. In this method very small urine samples equivalent of 0.5 μg creatinine are directly chromatographed without desalting together with an internal amino acid standard. This method yields chromatograms with reproducibly located spot patterns. The detection limit for most of the amino acids is in the range of 250–500 μg/100 ml urine. About 40 amino acids and other ninhydrin positive substances can be identified on the chromatograms. Because of simple procedure, of simple identification, and of good sensitivity the test is a useful tool for screening programs.

Thin-layer chromatographic screening tests for carbohydrate anomalies in plasma, urine and faeces

Abstract Thin-layer Chromatographic screening methods for anomalies of carbohydrate metabolism are described. For detection of anomalies with an increased plasma concentration of fructose and galactose in plasma or serum is one-dimensionally chromatographed on precoated plates without deproteinization. For detection of an abnormal urinary or faecal excretion urine (without desalting) or faecal extracts are two-dimensionally chromatographed together with an internal carbohydrate standard. Both methods are relatively simple and yield reproducible results with high sensitivity.