Analysis of Cannabinoids and Metabolites in Dried Urine Spots (DUS)

Abstract

Dried urine spots (DUS) represent a potential alternative sample storage for forensic toxicological analysis. The aim of the current study was to develop and validate a liquid chromatographic tandem mass spectrometric procedure for the detection and quantitative determination of cannabinoids and metabolites in DUS. A two-step extraction was performed on DUS and urine samples. An LC-MS/MS system was operated in multiple reaction monitoring and positive polarization mode. The method was checked for sensitivity, specificity, linearity, accuracy, precision, recovery, matrix effects and carryover. The method was applied to 70 urine samples collected from healthy volunteers and drug addicts undergoing withdrawal treatment. The method was successfully developed for DUS. LODs lower than 2.0 ng/mL were obtained for all the monitored substances. All the validation parameters fulfilled the acceptance criteria either for DUS or urine. Among the real samples, 45 cases provided positive results for at least one compound. A good quali-quantitative agreement was obtained between DUS and urine. A good stability of THC, THCCOOH and THCCOOH-gluc was observed after a 24 h storage, in contrast to previously published results. DUS seems to provide a good alternative storage condition for urine that should be checked for the presence of cannabinoids and metabolites.

The Determination of Cannabinoids in Urine Samples Using Microextraction by Packed Sorbent and Gas Chromatography-Mass Spectrometry

“…The current method achieves lower or similar LODs than the literature for: CBD [ 38 , 39 , 40 , 41 , 42 ]; THC [ 33 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ]; CBN [ 41 ]; 11-OH-THC [ 33 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ]; and THC-COOH [ 38 , 46 , 47 ]. The same LLOQs are reported for: CBD [ 39 , 40 , 41 , 42 , 48 , 49 ]; THC [ 33 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 48 , 49 ]; CBN [ 39 , 40 , 41 , 48 , 49 ]; 11-OH-THC [ 33 , 39 , 40 , 41 ,…”

“…When using a GC–MS system [ 41 , 43 , 44 ], the authors report greater LODs and LLOQs than those obtained with the herein proposed technique. The same happens when using systems with greater sensitivity, such as LC–MS/MS [ 38 , 39 , 40 , 42 , 45 , 46 , 47 , 48 , 49 ]. Nonetheless, some authors report lower LLOQs than those obtained with our MEPS–GC–MS, mostly using techniques with greater sensitivity, including GC–MS/MS [ 50 , 51 , 52 , 53 ] and LC–MS/MS [ 38 , 39 , 42 , 46 , 54 , 55 , 56 , 57 , 58 , 59 ]; several of these approaches also used larger sample volumes.…”

Monitoring Exposure to Five Chemical Warfare Agents Using the Dried Urine Spot Technique and Liquid Chromatography-Mass Spectrometry/Mass Spectrometry—In Vivo Determination of Sarin Metabolite in Mice

“…This method was successfully applied in non-targeted screening for drugs of abuse [12]. Because of these advantages, as well as the fact that urine is the preferred matrix for the detection of drugs [14], the incorporation of this technique has accelerated in recent years for toxicology screening [15], metabolite-based comprehensive screening [16], forensic toxicology [17], etc. DBS was explored for the detection of exposure to CWAs, with promising results [18][19][20][21].…”

Genetic individual identification from dried urine spots: A complementary tool to drug monitoring and anti‐doping testing

“…[1][2][3] The most important, as well as the most studied and widely applied DMS, [4][5][6][7] is the dried blood spots (DBS) technique, described for the first time by Guthrie and Susi in 1963 and used in neonatal screening for the diagnosis of congenital phenylketonuria. 8 In the following years, the sampling of biological matrices on paper supports was used on multiple body fluids, such as plasma (DPS), 9,10 urine (DUS), 11,12 saliva, 13 tears, 14 breast milk, 15 synovial fluid, 16 cerebrospinal fluid (CSF), 17 and amniotic fluid. 18 This diffusion is well explained by highlighting the numerous advantages that the use of DMS for laboratory analysis entails: ease of sampling, especially in case of blood; simplicity in transport and storage, being suitable to be kept at room temperature even for long periods of time; improvement in the quality of life of subjects suffering from chronic diseases who must undergo periodical analyses; and suitability to a multitude of different analytical approaches.…”