Simultaneous determination of THC-COOH and THC-COOH-glucuronide in urine samples by LC/MS/MS

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1 Forensic Science Interntionl (2000) locte/ forsciint Simultneous determintion of THC-COOH nd THC-COOH-glucuronide in urine smples by LC/MS/MS Wolfgng Weinmnn *, Susnne Vogt, Rolf Goerke, Cludi Muller, Andres Bromberger Institute of Forensic Medicine, Klinikum der Albert-Ludwigs-Universitt Freiburg, Albertstrsse, D-704 Freiburg, Germny Abstrct A fst method using liquid liquid extrction nd HPLC/ tndem-mss spectrometry (LC/ MS/ MS) ws developed for the simultneous detection of -Nor-D -tetrhydrocnnbinol--crboxylic cid b-glucuronide (THC-COOH-glucuronide) nd -Nor-D -tetrhydrocnnbinol--crboxylic cid (THC-COOH) in urine smples. This highly specific method, which combines chromtogrphic seprtion nd MS/ MS nlysis, cn be used for the confirmtion of positive immunossy results even without hydrolysis of the smple or derivtistion of extrcts. Liquid liquid extrction ws optimised: with ethylcette/ diethylether (:, v/ v) THC-COOH-glucuronide nd THC-COOH could be extrcted in one step. Moleculr ions of the glucuronide (MH, m/z 52) nd THC-COOH (MH, m/z 45) were generted using PE/ SCIEX turboionspry source in positive ionistion mode; specific frgmenttion ws performed in the collision cell of n API 65 triple-qudrupole mss spectrometer nd yielded mjor frgments t m/z 45 (for THC-COOH-glucuronide) nd m/z 27 s well s m/z 2 for both cnnbinoids. Chromtogrphic seprtion ws performed using reversed-phse C8 column nd grdient elution with 0.% formic cid/ mm mmonium formte nd cetonitrile/ 0.% formic cid. Retention times were 22.2 min for the glucuronide nd 26.8 min for THC-COOH. After enzymtic hydrolysis of urine smples with b- glucuronidse/ rylsulftse (78C, 5 h), THC-COOH-glucuronide ws no longer detectble by LC/ MS/ MS in urine smples. However, the THC-COOH concentrtion ws incresed. For quntittion of THC-COOH, THC-COOH-D ws dded to the urine smples s internl stndrd prior to nlysis. From the difference of THC-COOH in the ntive urine nd urine fter enzymtic hydrolysis, molr concentrtion rtios of THC-COOH-glucuronide/ THC-COOH in urine smples of cnnbis users were determined nd found to be between. nd Elsevier Science Irelnd Ltd. All rights reserved. Keywords: LC/ MS; Tndem-mss spectrometry; Cnnbinoids; Glucuronide; Urine nlysis. Introduction nd workplce drug testing. Proof of cnnbinoids in urine smples cn, under certin instnces, result in The detection nd confirmtion of cnnbinoids in withdrwl of the driving license in Germny. urine smples is importnt in forensic cses, e.g. Besides the mjor metbolite of tetrhydrocnnbinol cses concerning driving under the influence of drugs (-nor-d -tetrhydrocnnbinol-crboxylic cid), severl glucuronides of cnnbinoids hve been chrcterised by GC/ MS using electron impct nd *Corresponding uthor. Tel.: ; fx: chemicl ionistion fter derivtistion [ ], mong E-mil ddress: weinmnn@sun.ukl.uni-freiburg.de (W. which is the ester-linked b-glucuronide of -nor-d - Weinmnn). tetrhydrocnnbinol-crboxylic cid [2]. For hydrol / 00/ $ see front mtter 2000 Elsevier Science Irelnd Ltd. All rights reserved. PII: S07-078(00)0020-

2 82 W. Weinmnn et l. / Forensic Science Interntionl (2000) 8 87 Fig.. Enzymtic hydrolysis of THC-COOH-glucuronide. ysis of the ester-linked glucuronides, bsic hydrol- grdient mixer, diode rry detector (DAD) ysis [4] or enzymtic hydrolysis using b-glucuronid- SPDM0A, interfce module CBM0A nd 486/ 00 se from helix pomti re commonly used (Fig. ) DOS PC, column RP-C8-select B, 2 mm I.D.25 [5]. Due to the lck of specific nlysis procedures, mm, 5 mm prticle size (Merck, Drmstdt, Gerphrmkokinetic dt for the glucuronides re not mny). This HPLC/ DAD system ws coupled withvilble, so their presence in body fluids is not out split to PE/ SCIEX API 65 using regrded s being importnt. In generl, ester bond- TurboIonSpryE source. Deionised wter (,0. ms ing is known to be unstble to enzymtic or chemicl from crtridge deioniser, Memtech, Moorenweis, hydrolysis, but no informtion is vilble on the Germny), grdient grde cetonitrile, 25% queous stbility of THC-COOH-glucuronide in ny body mmoni nd formic cid (nlyticl grde, Merck) fluid. were used s HPLC solvents or for dissolving drug For the determintion of cnnbis influencing stndrds. For HPLC, the following grdient ws fctor (CIF) [6] from serum concentrtions of THC used with solvent A (5 mm mmonium formte/ nd its two metbolites (THC-COOH nd -hy- 0.% formic cid, ph ) nd solvent B (cetonitrile/ droxy-thc), the presence of THC-COOH-glucuro- 0.% formic cid): 0 min, B 0%; min, B nide in serum, nd its possible instbility with liner from 0 to 0%; min, B liner from respect to esterses, hs not yet been tken into 0 to 70%; min, B liner from 70 to 0%, considertion, but my ply n importnt role. With 4 min t 0% B. sensitive detection method, the importnce of THC- THC-COOH-D (internl stndrd) ws obtined COOH-glucuronides could gin weight for these from Promochem/ Rdin (Wesel, Germny). Prepfields of forensic toxicology. rtion of urine smples ws performed in the follow- Our im ws to develop LC/MS/MS method for ing wy: ml urine ws spiked with 00 ng THCthe simultneous detection of THC-COOH nd THC- COOH-D (per ml smple), nd 00 ml 0. M cetic COOH-glucuronide. This method ws developed by cid nd ml phosphte buffer (ph 6.0) were dded. the use of urine smples from cnnbis consumers. For determintion of totl THC-COOH, enzymtic hydrolysis ws performed by dding 70 ml of b- glucuronidse/ rylsulftse (Merck, Drmstdt, Ger- 2. Mterils nd methods mny) to ml urine (which ws prepred s bove) nd incubted t 78C for 5 h. Liquid liquid ex- The following instrumenttion ws used: PE/ trction ws performed with 2 ml of diethylether/ SCIEX API 65 triple-qudrupole mss spectrometer ethylcette (:, v/ v). After solvent evportion t with turboionspry source (PE/ SCIEX, Perkin- 458C, the residue ws redissolved with 00 ml HPLC Elmer, Lngen, Germny), nd n Apple Mcintosh solvent (A/B, :, v/v) nd 20 ml were injected into G Power PC, with MssChrom.0 nd Mutiview the LC/ MS/ MS system. Multiple rection moni-.4 softwre (PE/ SCIEX). HPLC system (Shimdzu, toring (MRM) ws used for the detection of THC- Duisburg, Germny): pump LC0AD, low pressure COOH-glucuronide, THC-COOH nd THC-COOH-

3 W. Weinmnn et l. / Forensic Science Interntionl (2000) Tble drds (with 0, 25, 50, 00, 500, 000, 5000 nd MRM trnsitions used for LC/ MS/ MS nlysis ng/ ml THC-COOH, respectively, nd 00 Compound MRM LC retention ng/ ml THC-COOH-D, ech) nd blnk urine trnsition time (min) smple, linerity ( y 5.0x) with good correltion THC-COOH coefficient (r 5 0.) ws obtined. glucuronide 45 2 THC-COOH THC-COOH-D Results Used s qulifier. For method development, ionspry ionistion mss D (Tble ), with the following ion source prme- spectr of THC-COOH-glucuronide, which hd been ters: orifice 0 V, ring 20 V, needle 5250 V. extrcted from ntive urine smple, were cquired Stndrd ionspry conditions were used [6]. t low nd high orifice voltges (0 nd 50 V) using For clibrtion of THC-COOH quntittion by single-qudrupole mode, to obtin informtion on the MRM, spiked urine smples were nlysed nd the frgmenttion in the ion source (ESI/ CID) [7]. Even intensity rtios of the MRM trnsitions of THC- t low orifice voltge the moleculr ion MH (m/z COOH nd THC-COOH-D (Int. 45 2/ Int. 52) dissocited into its chrcteristic frgment ions 48 2) were determined in reltion to the con- (Fig. 2) with reltive moleculr ion intensity of centrtion rtios [THC-COOH (ng/ ml)/ THC- pproximtely 8% of the bse pek intensity. At 50 COOH-D (ng/ ml)]. Using eight clibrtion stn- V orifice, more frgmenttion occurred. Further Fig. 2. Reconstructed ionspry ionistion mss spectrum of THC-COOH-glucuronide extrcted from urine smple using selected ion monitoring. Increse of orifice voltge lso incresed the frgmenttion of MH (m/z 52). A sodium dduct of THC-COOH-glucuronide (m/z 54) ws not detected.

4 84 W. Weinmnn et l. / Forensic Science Interntionl (2000) 8 87 experiments using MS/ MS were therefore performed for both THC-COOH-glucuronide nd THC-COOH t low orifice voltge (0 V). were chieved with ethylcette/ diethylether (:, For the development of the MRM method the v/ v). All further extrctions were therefore perproduct ion spectr of the trget substnces were formed with ethylcette/ diethylether (:, v/ v). cquired. For THC-COOH-glucuronide, no reference No THC-COOH-glucuronide-D ws vilble for stndrd ws vilble, so tht cnnbinoid-positive determintion of the detection limits of the LC/ MS/ urine ws extrcted nd nlysed by LC/ MS/ MS MS method. However, for estimtion of the detection with product ion scnning of MH (m/z 52). For limits using signl-to-noise rtios (S/N), mss THC-COOH nd THC-COOH-D, reference com- spectrometric response fctor (F ) ws determined by pounds were used. Product ion spectr re shown in compring the intensities of the MRM trnsitions of Fig.. THC-COOH-glucuronide nd THC-COOH-D in the A multiple rection monitoring experiment tested urine smples of cnnbis consumers in the (MRM) ws set up using the trnsitions shown in following wy: Tble. The most chrcteristic trnsition (52 45) from the frgmenttion of the moleculr F 5 ion ws used for identifiction of THC-COOH-gluc- [THC-COOH-glucuronide (ng/ ml)] uronide. Due to ESI/ CID nd subsequent MS/ MS ]]]]]]]]]]]]]] [(int )/(int )][mount of ISTD (ng/ ml)] frgmenttion, THC-COOH-glucuronide lso yielded trnsition of n ESI/ CID-generted frgment where int. is the intensity of the MRM trnsition nd (45 2) t t min, which ws bout twice ISTD is the internl stndrd, THC-COOH-D. s intensive s the trnsition However, The response fctors for the tested urine smples becuse of its lower specificity, it ws used s re listed in Tble 2, yielding n verge of qulifier. Ntive nd hydrolysed urine extrcts nd This response fctor indictes tht the clibrtion series of spiked urine smples (see bove) MS/ MS method ws pproximtely.7 times more were nlysed using the MRM method. Chromto- sensitive for THC-COOH-D thn for THC-COOHgrms of the trnsitions re shown for one urine glucuronide with respect to detectble mounts in smple (urine No. 02) in ntive nd hydrolysed ng/ ml. From the clibrtion with spiked urine smstte in Fig. 4. After enzymtic hydrolysis t 78C ples, the detection limit (t S/N 5 ) for THCfor 5 h, the trnsitions chrcteristic for THC- COOH ws,0 ng/ ml. COOH-glucuronide were below the detection limit (signl-to-noise rtio,), wheres the bundnce of the trnsition chrcteristic for THC-COOH ws incresed. The mount of relesed THC-COOH ws 4. Discussion nd conclusion clculted using the internl deuterted stndrd nd clibrtion with spiked urine smples. Concentr- A sensitive nd specific LC-ionspry-MS/ MS tions found re listed in Tble 2. Rtios of molr method for the simultneous determintion of THCconcentrtions of THC-COOH-glucuronide/ THC- COOH-glucuronide nd THC-COOH in urine sm- COOH in urine smples determined by this pro- ples ws developed. Until now, THC-COOH-gluccedure were between. nd 4.5. uronide hs not been detected by routine toxicologi- For optimising the extrction efficiency, five dif- cl nlysis, so tht it ws not considered importnt ferent orgnic solvents or mixtures were tested for for forensic cses. However, the quntittion of the simultneous extrction of THC-COOH-glucuro- THC-COOH-glucuronide in reltion to THC-COOH nide nd THC-COOH from urine smple prepred in urine my become importnt when looking t s described in Mterils nd methods: () iso-oc- consumption hbits (single intke or frequent intke tne, (b) hexne/ethylcette : (v/v), (c) hexne/ over long period) due to differences in elimintion ethylcette 7: (v/ v), (d) methylenechloride/ 2-pro- rtes. With the presented method, the detection of pnol/ ethylcette :: (v/ v), (e) ethylcette/ di- THC-COOH-glucuronide might lso be possible in ethylether : (v/ v). The best extrction efficiencies serum smples, which is the im of our current work.

5 W. Weinmnn et l. / Forensic Science Interntionl (2000) Fig.. Product ion mss spectr by MS/ MS of the moleculr ions (MH ) of THC-COOH-glucuronide (), THC-COOH (b) nd THC-COOH-D (c). importnt role for models, such s the cnnbis influencing fctor (CIF), which tke into consider- tion the concentrtion of free THC-COOH for the The stbility of THC-COOH-glucuronide due to smple storge nd the rtio of THC-COOH-glucuronide to THC-COOH in serum might then ply n

6 86 W. Weinmnn et l. / Forensic Science Interntionl (2000) 8 87 Fig. 4. Urine extrcts nlysed by LC/ MRM: () ntive urine extrct (urine No. 02 ntive); (b) urine extrcted fter glucuronidse tretment (urine No. 02 hy). Pek res re indicted. supplier of forensic drug stndrds (Alltech, USA), but hs recently been stopped becuse it ws too expensive, therefore the quntittion of THC-COOH- glucuronide in body liquids remins chllenge. A combintion of enzymtic hydrolysis with mss judgement of driving impirment of cnnbis consumer. Deuterted stndrds of THC-COOH-glucuronide re currently not vilble. Synthesis of deuterted THC-COOH-glucuronide hs been performed by one

7 W. Weinmnn et l. / Forensic Science Interntionl (2000) Tble 2 Results of LC/ MS/ MS nlysis of ntive nd hydrolysed urine smples Urine int / int. 45 2/ [THC-COOH] [THC-COOH- Conc. F No. int int b (ng/ ml) glucuronide] d rtio c (ng/ ml) 02 ntive f 02 hy g ntive hy ntive hy ntive hy ntive hy ntive hy ntive hy ntive hy ng THC-COOH-D dded per ml smple. b Concentrtions clculted using clibrtion with spiked urine smples. c Concentrtions clculted from the difference of THC-COOH concentrtions in ntive nd hydrolysed urine smples. d Rtio of concentrtions (THC-COOH-glucuronide/THC-COOH). e Mss spectrometric response fctor. f hy, urine smple fter enzymtic hydrolysis. g, trnsition not detectble. e 8 spectrometric response fctors could be helpful for D -tetrhydrocnnbinol nd D -tetrhydrocnnbinol, estimting the detectble concentrtions, wheres the Biomed. Mss Spectrom. 4 (77) 0 6. [4] M. Hnke, G. Megges, Routine-Nchweis des THC-Metbouse of reference compounds would give more precise liten -Nor-D -tetrhydrocnnbinol--crbonsure in der results. forensischen Prxis, Z. Rechtsmed. 0 (8) [5] P.M. Kemp, I.K. Abukhlf, J.E. Mnno, B.R. Mnno, D.D. Alford, M.E. McWillims, F.E. Nixon, M.J. Fitzgerld, R.R. References Reeves, M.J. Wood, Cnnbinoids in humns: II. The influence of three methods of hydrolysis on the concentrtion of THC nd two metbolites in urine, J. Anl. Toxicol. [] P.L. Willims, A.C. Mofft, Identifiction in humn urine of (5) D-tetrhydrocnnbinol--oic cid glucuronide: tetrhy- [6] T. Dldrup, I. Meininger, Der Cnnbis Influencing Fctor drocnnbinol metbolite, J. Phrm. Phrmcol. 2 (80) (CIF), in: G. Berghus, H.-P. Kruger (Eds.), Cnnbis im Strßenverkehr, Gustv Fischer, Stuttgrt, 8, pp. [2] S. Pllnte, M.A. Lyle, C. Fenselu, Synthesis nd chrc- 5. teriztion of glucuronides of 5-hydroxy-D-tetrhydrocn- [7] W. Weinmnn, A. Wiedemnn, B. Eppinger, M. Renz, M. nbinol nd -hydroxy-d-tetrhydrocnnbinol, Drug Svobod, Screening for drugs in serum by electrospry Metb. Dispos. 6 (78) 8 5. ioniztion/ collision-induced dissocition nd librry serch- [] M.A. Lyle, S. Pllnte, K. Hed, C. Fenselu, Synthesis nd ing, J. Am. Soc. Mss Spectrom. 0 () chrcteriztion of glucuronides of cnnbinol, cnnbidiol,