Iii ! February19_ journalof AnalyticaTl oxicologyVol., 16,January/Februar1y992 · 489: 23-5Q A.Fritz.The[-- I _etabolicfate d humanv0_ Distinguishing SympathomimeticAminesfrom zolol metab0. Amphetamin andMethamphetamineinUrineby 1Dope Anal. · Zur Darste_ GasChromatography/MassSpectrometry thylsilyl- und lern von Ke. E.M. Thurman, M.J. Pedersen, R.L. Stout, and T. Martin tografische Clinical Reference Laborato_ 11850 W. 87th Street, Lenexa, Kansas 66214 e Untersuc. · 02:483-86 }umasia, ar_ _/column gas ion chemical o confirm the Abs_'"_ Although GC/MS methods are available for all five classes of icosteroidsto L -'---_ drugs, including amphetamine and metharnphetamine (4--6), there _ectrom. S: Derivatives of seven commonly used sympathomimetic is a need for understanding the possible interference caused by amines and two "designer amines" were isolated from urine, sympathomimetic amines. This is especially critical in light of the ,xymetholom separated chromatographically from amphetamine and recent N[DA action to suspend a certified laboratory in the per- )pe Analysis, methamphetamine, and determined by mass spectrometry formance of amphetamines by GC/MS based on an erroneous with selected ion monitoring. The drugs included ephedrine, analysis, which was caused by possible interference from ephe- ;riconchaanaboliractere, hydroxypropylhenxedrinorepheedri, pseudoene, phepnhyelephridrinen, e,phenphenylpropanotermine,lamine, drine, a sympathomimetic amine (7-9). Furthermore, NIDA re- Biomed. En. methylenedioxyamphetamine (MDA), and methylenedioxy stricted the use of the 4-CB reagent for methamphetamine from methamphetamine (MDMA). The drugs were liquid extracted October 12 to December 21, 1990 (8,10) and required identifi- steroids. The from urine and derivatized by either heptafluorobutyric cation by another derivatization procedure, such as HFBA (8). Jrostadien-3. anhydride (HFBA) or 4-carbethoxyhexafiuorobutyryl chloride Since December 21, 1990,NIDA has instructed its certified labora- _sSpectrorn. (4-CB). Because the base peak ions for ephedrine, tories that methamphetamine may be reported positive by the 4-CB pseudoephedrine, propylhexedrine, MDMA, and phentermine reagent if the specimen also contains the metabolite, amphetamine, on anabolic are identical to methamphetamine (e.g. 254 ainu for HFBA) and at concentrations equal to or exceeding 200 ng/mL (10). >zolol urinary those for phenylephrine, hydroxynorephedrine, Several recent papers have dealt with the analysis of amphet- ctrometry. J. {phene.g.y240lpropaamunolaforminHFBA),e, anda tableMDAofareselecteidenticdaliontos awasmphetamine amines by GC/MS (4-6,11-12), but in these reports there is not _pl.3): 25-35 developed for all 11 drugs that distinguished amphetamine and a detailed discussion of the interfering ions caused by the sym- methamphetamine from the sympathomimetic amines with pathomimetic amines. Consequently, our paper describes (1) the of danazolin either HFBA or 4-CB. The distinguishing ions rely on the ring chromatography required to separate the common sympathomi- 'uate Med. J, structure of the different drugs and fragmentation associated metic amines that interfere with either amphetamine or metham- with that structure. The 4-CB reagent partially derivatized the phetamine, (2) the mass spectral fragments of each of the ,sis and infer, hydroxy-containing sympathomimetic amines, while the HFBA common sympathomimetic amines using derivatization with ei- mazol. Post. completely derivatized all the sympathomimetic amines, ther heptafluorobutyric anhydride or 4-carbethoxyhexafluorobu- Furthermore, false positive results for the 4-CB reagent were tyryl chloride, (3) the distinguishing SIM ions that can be used to ol in the man- found only for methamphetamine (20-2250 ng/mL of identify each of the sympathomimetic amines from amphetamine }pl. 3): 86-91 methamphetamine) when high concentrations (> 5 gg) of and methamphetamine, and (4) false positives for metham- Theseephedrinresultse or pareseudoerelatedphedrineto a cowerembinaptrionesentof iinjecn thetiospnecimporetn, phetamine that result from the presence of ephedrine or pseudo- temperature and cleanliness of the injection port sleeve, ephedrine in the specimen when using the 4-CB reagent. Introduction Materials and Methods In the last several years urine drug testing has become much Instrumentation more prevalent in the work place; for example, drug testing is A Model 5890A Hewlett-Packard gas chromatograph with mandatory in certain trades, such as aviation and trucking (1-2). 5971B mass selective detector was used for the analysis. The data The National Institute on Drug Abuse (NIDA) has set stringent system was an HP 310 computer with an HP 59970C MS/MSD guidelines (3) for laboratories to follow l_oraccurate and precise Chemstation. The MSD was operated in the electron impact analysis of the five classes of drugs of abuse (mnphetamines, can- mode (EI) at 70 eV with an ion source temperature of 200°C and nabinoids, cocaine, opiates, and phencyclidine). These guidelines an m/z range for selected ions that varied with the drug or metabo- require gas chromatographic/mass spectrometric (GC/MS) iden- lite analyzed (Table I) or in the scan mode from 40 to 650 amu. tiiicafion of the drugs o1'abuse, as well as quantitation by GC/MS. The instrument was autotuned daily with perfluorotributylamine Reproduction (photocopying) of editorial content of this journal is prohibited without publisher's permission. 19 F JournalofAnalyticalToxicologyVoL, 16,January/February199:). Journ_ (PFTBA). The GC/MS interface temperature was 285°C. A 91, 118, 248, 266, and 294 for amphetamine; nv'z 92, 121,250, docpl fused-silica capillary column (HP-5) 12.5 m × 0.2 mm i.d. and 269, and 297 for d3-amphetamine; m/z 91, 118,262, 280, and 308 The t 0.33-}.n-n film thickness, consisting of cross-linked 5% phenylsil- for methmnphetmnine; and m/z 92, 119,266,284, and 312 for d5- phcm icone gum phase, was used for all drugs of abuse. The helium nlethamphetamine (Table I). A 50-ms dwell time is used 1hr all cause flow rate was 0.65 mL/min at a linear velocity of 35 cm/s. The Dp- ions. Quantitation ions are nv'z 294 and 297 for amphetanline and moth; erating temperature of the column varied with the analytes. The d3-amphetamine and ,v'z 308 and 312 for methamphetamine and tcrfct injection temperature varied from 180 to 265°C, and the injection ds-methamphetamine. Ta' was splitless. The heptafluorobutyricanhydrideprocedureis as follows:To theit a 10-mL test tube add 2.0 mL of urine and spike with 1250 ng of tized Chemicals and reagents d3-amphetanline and 1250 ng of ds-methamphetamine in 50 gL of pseu, Toxi-A tubes were from Toxi-Lab. Methanol, ethyl acetate, deionized water. Extract the sample in a Toxi-Lab A-Tube for 5 tical hexane, methylene chloride, acetic acid, ammonium hydroxide, min using a rotating shaker. Centrifuge the A-Tube and pipette off peak hydrochloric acid, phosphoric acid, and chloroform were Fis- the organic phase. Add 400 gL of methanol and 25 gL of acetic drug cher Scientific analytical reagent grade chemicals. Isopropanol acid. Next evaporate the specimen to dryness at 45°C under ni- HFB was from Mallinkrodt. Heptafluorobutyric anhydride (HFBA) trogen. Add 50 gL of heptafluorobutyric anhydride and seal tube. 254 was obtained from Alltech. The 1-chlorobutane and anhydrous Heat at 75°C for 15 min. Evaporate the HFBA under nitrogen at (whi ethyl alcohol was from Aldrich Chemical Company. The 4-carb- 50°C to dryness. Add 100 gL of ethyl acetate and inject I gL into atoxx ethoxyhexafluorobutylchloride (4-CB) was from PCR Incorpo- the GC/MS. thes( rated. The following internal standards were used: 2H3-amphet- The injector temperature is 210°C, the column temperature is tific_ amine and 2Hs-methamphetamine (Sigma Chemical Company). 60°C for the first minutes, to 225°C at 20°C/min with a hold time syml of 0.75 rain, followed by a 70°C/min ramp to 260°C and hold for B_ Procedure 2.0 min. Run time is 12.5 min with amphetamine eluting at 6.32 to m To a 10-mL test tube add 2.0 mL of urine and spike with 1250 min and methamphetamine eluting at 7.04 min for HFBA. Equi- mett ng of d3-amphetamine and 1250 ng of ds-methamphetamine in 50 libration time is 0.50 min with a 0.75-min purge off time. The gaw gL of deionized water. Extract the sample in a Toxi-Lab A-Tube transfer line temperature is 285°C. The solvent delay is 4.0 min fere_ for 5 minutes using a rotating shaker. Centrifuge the A-Tube and and the electron multiplier is set at autotune voltage, phet pipette off the organic phase. Add 400 gL of methanol and 25 gL The ions with HFBA are m/z 254, 210, 118, and 91 for pro[ of acetic acid. Next evaporate the specimen to dryness at 45°C methamphetamine; m/z 258, 213, 119, and 92 for the ds-metham- spec under nitrogen. Add 200 gL of 4-carbethoxyhexafiuorobutyryl phetamine. For amphetamine they are m/z 240, 169, 118, and 91; liun chloride in 1-chlorobutane (1:100, v/v). Cap, vortex, and heat for for d3-amphetamine they are m/z 243, 121, and 92 (Table I). ture 15 min at 50°C. Next add 300 gL of anhydrous ethanol and heat Quantitation ions for methamphetamine-HFBA are m& 254 and sligl at 50°C for 15 more minutes. Evaporate the specimen to dryness 258 for the ds-methamphetamine; for amphetamine-HFBA they bott at 45°C under nitrogen. Take up the specimen in 100 gL of ethyl are m/z 240 and 243 for d3-amphetamine, sma acetate and inject 1 gL into the GC/MS. For the standard Met sympathomimeticamines,5 gg of eachcompoundwastakenup 167, in a methanolsolution,transferredto a testtube,evaporatedto ^ dryness, and derivatized as described. Results and Discussion was The injector temperature is 210°C, the column temperature is 60°C for the first minute to 225°C at 25°/min with a hold time of Derivatization with HFBA 2.4 min followed by a 70°/min ramp to 260°C and hold for 2.0 Figure 1 shows the sympathomimetic amines that have inter- min.