A rapid capillary electrophoresis method with LED-induced native fluorescence detection for the analysis of cannabinoids in oral fluid

Abstract

In the present study, a capillary electrophoresis method with native fluorescence detection for the quantification of the two main marijuana cannabinoids, tetrahydrocannabinol (THC) and cannabidiol (CBD), in oral fluid is described. The reported CE method makes it possible to assess illegal cannabis use in approximately 10 min, including saliva sample collection, pre-treatment procedures and capillary electrophoresis (CE) analysis. The proof of the principle, demonstrated on a home-made lab scale instrument, has a potential to be easily translated onto a truly portable instrument for on-site measurements. The saliva sample collection/preparation/pre-concentration procedure was combined into one step using the Salivette ® sampling device. No separate precipitation of proteins and/or derivatisation was required. The baseline CE separation of the two cannabinoids was achieved in less than 7 min by applying non-aqueous background electrolyte (BGE), composed of a 2.5 mM sodium hydroxide in a methanol-acetonitile mixture (1:1). Cannabinoids were detected at their second λex/λem maximum (280/307 nm) with LODs values of 0.19 and 0.17 µg/mL for THC and CBD, respectively. The recovery of the cannabinoids from the collection pad was greater than 80% for both cannabinoids tested at 2.5 µg/mL, and the inter-day precision was less than 6% for all analytes. The procedure was applied to oral fluid specimens after the controlled al libitum smoking of one cannabis cigarette.

Paper surface modification strategies employing N-SBA-15/polymer composites in bioanalytical sensor design

“…Fluorescence detection represents an alternative option due to its high sensitivity and fast response time. Among the light sources, the light emitting diode (LED) induced fluorescence has recently called the interest because LEDs combine high stability, small size, low cost, broad spectra, long lifetime and low energy consumption [7][8][9].…”

Adduct-ion formation in trapped ion mobility spectrometry as a potential tool for studying molecular structures and conformations

“…This makes THC a drug of abuse and correct identification of this compound is thus important from a forensic point of view. The two cannabinoids, can be separated using chromatographic or electrophoretic methods, such as planar chromatography [35], LC-UV [36], LC-MS(MS) [37,38], CE-LED-induced fluorescence detection [39], which require a considerable analysis time (5-30 min). In the present study, we studied the potential of TIMS for the fast separation of THC and CBD.…”

Single-run separation and quantification of 14 cannabinoids using affinity non-aqueous capillary electrophoresis

“…The method described separated four cannabinoids (THC, CBD, CBN, THCA) using a very similar running background electrolyte with sodium hydroxide as an electrolyte, however, in a fully non-aqueous environment, and with electrochemical detection in contrast to UV absorption. Another study with a similar method separated only THC and CBD in oral uids; however, they employed LED-induced uorescence for detection, with 280 nm excitation and 307 nm emission 15 . A different approach was picked in a study from 1998, where the stationary phase was involved in capillary electrochromatography to facilitate the separation of structurally similar cannabinoids 16 .…”