Principles and Practice of Chromatography - Chromatography Applications > Liquid Chromatography Applications > Page 81


Courtesy of Supelco Inc.

Figure 42. Chromatograms of Tetrahydrocannabinol Car-boxylic Acid from Urine


The chromatograms obtained from a urine sample and a reference standard by this procedure is shown in figure 42. This is a typical application for liquid chromatography using a solid phase extraction cartridges. It is seen that the tetrahydrocannabinol carboxylic acid is clearly and unambiguously separated from the contaminating materials with an extraction efficiency of over 90%. The chromatographic conditions were as follows.

Column LC 18
Column Length 25 cm
Column Diameter 4.6 mm
Column Packing C18 Reverse Phase, (octadecyldimethyl chain)
Mobile Phase 55% acetonitrile 45% aqueous 1% acetic acid
Flow-Rate 2.5 ml/min.
Detector UV adsorption at 280 nm
Sample Volume 100ml containing 500 ng tetrahydrocannabinol