Assessment of a natural extraction phase in disposable pipette extraction coupled with the sub-minute determination of 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid in human urine by fast-GC-FID

• Published in: Sustainable chemistry and pharmacy Vol. 20; p. 100390
• Main Authors: Morés, Lucas, Borges, Gabriela Ramos, Saga Kitamura, Rodrigo Ossamu, Eller, Sarah, de Oliveira, Tiago Franco, Carasek, Eduardo, Merib, Josias
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.05.2021
• Subjects: Biosorbent; DPX; Fast-GC-FID; Sample preparation; THC-COOH; Fast-GC-FID; Biosorbent; THC-COOH; Sample preparation; DPX
• ISSN: 2352-5541; 2352-5541
• DOI: 10.1016/j.scp.2021.100390

The compound 11-nor-Δ9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) consists of the major metabolite of tetrahydrocannabinol (THC) in human urine. Analysis of this compound exhibits an important role in forensic scenario; therefore, several analytical methods have been developed for this purpose. In this study, for the first time, a biosorbent-based disposable pipette extraction was developed for the determination of THC-COOH, using a simple and high-throughput sample preparation technique. In addition, a rapid instrumental analysis was achieved by fast-gas chromatography coupled with flame ionization detection (fast-GC-FID). Different biosorbents were examined, including cork, moringa and bract. The method was optimized through univariate and multivariate designs with the conditions comprised of 15 mg of cork as the extraction phase, pH maintained at 2.5 with 8 cycles of extraction of 60 s each, and 1 cycle of 5 s for the desorption step with a mixture of acetonitrile:methanol (ACN/MeOH). Limit of detection was 0.21 ng mL−1 and the limit of quantification was 0.73 ng mL−1, with a linear range from 5 to 100 ng mL−1 and coefficient of determination (R2) 0.9905. The relative recoveries ranged from 96 to 108%, intraday and interday precisions were lower than 13%. Different samples were subjected to the extractions using the method developed with four positive samples for the analyte. [Display omitted] •A renewable/biodegradable sorbent phase was proposed for the determination of THC-COOH in human urine.•A straightforward and high-throughput DPX-based procedure was achieved.•Low solvent consumption was required.•Chromatographic determination within 1 min was possible using fast-GC-FID.