Comparison of the drug concentrations in oral fluid collected by two sampling methods (Varian OraLab and Statsure Saliva•Sampler)

Abstract

-Objective:To determine the influence of oral fluid sampling methods on drug concentrations. Methods: Oral fluid was obtained from 249 subjects by Varian OraLab and Statsure Saliva•Sampler. The OraLab consists of foam-tipped oral fluid collector. The sponge contains a salt that stimulates salivation. The Saliva•Sampler consists of a collector with a blue indication when 1 mL of oral fluid is collected. After sampling, the collector is transferred to a tube that contains 1 mL of buffer. Oral fluid was analysed for seven drugs with UPLC-MSMS. Results: For all the tested drugs, the concentrations in the oral fluid collected with OraLab were 37-76% compared to Statsure. Possible explanations are: a buffer and surfactants could explain a better extraction recovery with Statsure (particularly for THC) and the stimulation of salivation by a salt could explain lower concentrations in OraLab. A comparison of the concentrations in both samples showed a wide scatter with relatively low correlation coefficients (0.56-0.90). Conclusions: For all tested drugs, the concentrations measured in the oral fluid collected by OraLab are lower. This could have consequences for the determination of legal cut-offs.Key words: Saliva, point-of-collection testing, street drugs/analysis Résumé -Objectif : Déterminer l'influence de la méthode d'échantillonnage dans la salive sur les concentrations des drogues. Méthodes : La salive a été obtenue chez de 249 sujets par Varian OraLab et Statsure Saliva•Sampler. L'OraLab se compose d'une tige avec une éponge qui absorbe la salive. L'éponge contient un produit salé qui stimule la salivation. Le Saliva•Sampler se compose d'un collecteur avec une indication bleue quand 1 mL de salive a été collecté. Après le prélèvement, le collecteur est transféré dans un tube qui contient 1 mL de tampon. Sept drogues ont été analysées dans la salive par UPLC-MSMS. Résultats : Pour toutes les drogues testées, les concentrations dans la salive recueillie avec OraLab étaient de 37-76 % par rapport à Statsure. Les explications possibles de ces différences sont la présence d'un tampon et de surfactants qui pourrait expliquer une meilleure extraction avec le Statsure (en particulier pour le THC) et la stimulation de la salivation par un sel dans l'OraLab pourrait également expliquer les plus faibles concentrations. La comparaison des concentrations dans les deux échantillons montre une grande dispersion avec des coefficients de corrélation relativement faibles (0,90). Conclusions : Pour toutes les drogues, les concentrations mesurées dans la salive collectées par OraLab sont plus basses. Cela pourrait avoir des conséquences pour la détermination des seuils médico-légaux.

Prevalence of Psychoactive Substances in Dutch and Belgian Traffic

“…The collection procedure may have infl uenced the concentrations of the samples, as described in previous literature (Crouch, 2005;Langel et al, 2008;O'Neal et al, 2000;Verstraete et al, 2011a). Furthermore, a recent study (Houwing et al, submitted for publication) shows that THC concentrations in oral fl uid samples collected by spit tubes were on average 1.9 times higher than THC concentrations collected by the StatSure collection device.…”

Mass Spectrometry-Based Metabolomics of Phytocannabinoids from Non-Cannabis Plant Origins

“…This may, however, interfere with the genuine cannabinoid content and also consume more time and increase cost. Alternatively, LC coupled with MS in selected ion monitoring (SIM) mode and MS2 in multi reaction monitoring (MRM) mode are the most commonly used detectors along with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and LC quadrupole-time of flight MS [ 36 , 37 ]. However, the matrix complexion can significantly affect the ion sources such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI).…”

Analytical approaches for the determination of phytocannabinoids and endocannabinoids in human matrices

“…The extraction of phytocannabinoids from OF is generally carried out using SPE, [15,31,99,[150][151][152][153] SPME, [154,155] and LLE. [14,45,147,[156][157][158] Polymer monolith microextraction (PMME) [159] and micro extraction on packed sorbent (MEPS) [143] have been also reported. Some authors proposed a method with direct injection of OF samples [160] but, despite the lower amount of proteins found in OF with respect to blood, extensive sample preparation is needed in order to avoid relevant matrix effects.…”

“…Although LC might be coupled with electrochemical [10,11] or spectrophotometric detectors, [12,13] MS in selected ion monitoring (SIM) mode and MS 2 in multi reaction monitoring (MRM) mode remain the most widely employed detector. In order to increase the performance of analysis, lately ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) [14] and LC quadrupole-time of flight MS (Q-TOF-MS) [15] have also been employed. However, the ion sources used for LC-MS, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI), can be strongly affected by the matrix effect; thus it is crucial to have a pretreatment able to remove efficiently the interfering compounds causing of ion suppression/enhancement.…”