Development of a liquid chromatography mass spectrometry method for the determination of tryptamines in whole blood

Abstract

The recent development and distribution of new psychoactive tryptamines has caused increased use in Norway. This has exposed a need to develop sensitive and robust determination methods for forensic cases involving tryptamines. Therefore, the aim was to develop a sensitive determination method for 21 tryptamines in whole blood. Three different separation columns were compared with different chromatographic parameters. Five different sample preparation methods were tested, Protein precipitation with Captiva ND filter plates and Captiva EMR filter plates, liquid-liquid extraction, solid phase extraction and electromembrane extraction. Protein precipitation with Captiva EMR lipid filter plates gave the best recoveries and precision for all the tryptamines except those with a hydroxy substituent, these could only be extracted after addition of ascorbic acid prior to protein precipitation, lipid plate filtration, and analysis by ultra-high-performance liquid chromatography and tandem mass spectrometry. The final method was evaluated using three analysis series and could determine 19 tryptamines with LODs between 0.14 and 0.6 ng/mL and linear ranges between 0.4 and 1512 ng/mL with R2 values above 0.99. The results satisfy international guidelines and are promising with respect to a full validation.