A highly sensitive and accurate electrospray liquid chromatography tandem-mass spectrometry (ESI-LC–MS/MS) method for determination of testosterone in human serum and saliva was developed and validated. Accurate quantification of testosterone in human matrices is essential in diagnosis and management of androgen status in men, women and children, and in forensic investigations of suspected abuse of anabolic androgenic steroids. Chromatography was performed on an HSS-T3 C18 column with a total run-time of 5.5 min. The tandem mass spectrometry was operated in positive electrospray ionization mode with multiple reaction monitoring. Serum and saliva samples of 200 μL, were prepared by solid-phase extraction using a 96-well plate following precipitation with 200 μL methanol. 13C labeled testosterone was used as internal standard for quantification. The standard curve was linear within the range of 4−1000 pg/mL and the limit of quantification of both serum and salivary testosterone was 4 pg/mL. Accuracy were 99–101 % and 93–95 % with between-run imprecision in serum and saliva, respectively, and inter- and intra-assay coefficients of variation were less than 9.2 %. The method proved to be applicable for determination of testosterone over a wide range of concentrations in serum and saliva samples from clinical patients with various androgen disorders, healthy male and female adults as well as from forensic cases.

At the Swedish national forensic toxicology laboratory, a measured testosterone/epitestosterone (T/E) ratio?≥?12 together with testosterone/luteinizing hormone (T/LH) in urine?>?400?nmol/IU is considered as a proof of exogenous testosterone administration. However, according to the rules of the World Anti-Doping Agency (WADA), samples with T/E ratio?>?4 are considered suspicious and shall be further analysed by gas chromatography?combustion?isotope ratio mass spectrometry (GC-C-IRMS) to confirm the origin of testosterone and its metabolites. The aim of this study was to investigate the possibility of false negative results and to estimate the frequency of negative results using the current criteria for detection of abuse of testosterone in forensic investigations. Urine and serum samples were collected by the police at suspected infringement of the doping law in Sweden. Fifty-eight male subjects were included in the study. Urinary testosterone was determined by gas chromatography?mass spectrometry (GC?MS), serum testosterone and LH?by immunoassay. The origin of testosterone and its metabolites was confirmed by means of GC-C-IRMS. Twenty-six of the 57 analysed subjects tested positive for exogenous testosterone using the criteria T/E?≥?12 combined with T/LH?>?400?nmol/IU. The IRMS analyses confirmed 47 positives; thus, 21 were considered false negatives. Negative predictive value was 32% (95% confidence interval [CI]: 16%?50%) and sensitivity 55%. No false positive subjects were found. The number of false negative cases using the current criteria for the detection of testosterone abuse and hence the low sensitivity indicates a need to discuss introduction of new strategies in forensic doping investigations.

New psychoactive substances are emerging on the illegal drug market. Synthetic opioids including fentanyl analogues are of special concern due to their high potency. This indicates the possibility of low drug concentrations in vivo and calls for sensitive analytical methods and identification of the most appropriate analytical targets. In this study the in vitro metabolism of ortho-, meta- and para-fluorofentanyl, three fluorinated derivatives of fentanyl, has been investigated using human hepatocytes and compared to the results from an authentic human urine sample. Based on knowledge on the metabolism of similar fentanyl analogues N-dealkylation and hydroxylation was hypothesized to be the most central pathways. The three fluorofentanyl isomers were incubated with pooled human hepatocytes at 1, 3 and 5 h. Liquid chromatography quadrupole time of flight mass spectrometry operating in data-dependent mode was used to analyse the hepatocyte samples, as well as the hydrolysed and non-hydrolysed authentic urine sample. Data were analysed by a targeted approach with a database of potential metabolites. The major metabolite formed in vitro was the N-dealkylation product norfluorofentanyl. In addition various hydroxylated metabolites, a N-oxide, dihydrodiol metabolites and a hydroxymethoxy metabolite were found. In total, 14 different metabolites were identified for each fluorofentanyl isomer. In the authentic urine sample, three metabolites were detected in addition to the ortho-fluorofentanyl parent compound, with hydroxymethoxy metabolite having the highest abundance followed by norfluorofentanyl and a metabolite hydroxylated on the ethylphenyl ring. This in vitro study showed that the metabolic pattern for ortho-, meta-, and para-fluorofentanyl was close to those previously reported for other fentanyl analogues. We suggest that the hydroxymethoxy metabolite and the metabolite hydroxylated on the ethylphenyl ring should be the metabolites primarily investigated in further studies to determine the most appropriate marker for intake of fluorofentanyl derivatives in urine drug screening for human subjects.

Tramadol is a complex drug, being metabolized by polymorphic enzymes and administered as a racemate with the (+)- and (-)-enantiomers of the parent compound and metabolites showing different pharmacological effects. The study aimed to simultaneously determine the enantiomer concentrations of tramadol, O-desmethyltramadol, N-desmethyltramadol, and N,O-didesmethyltramadol following a single dose, and elucidate if enantioselective pharmacokinetics is associated with the time following drug intake and if interindividual differences may be genetically explained. Nineteen healthy volunteers were orally administered either 50 or 100 mg tramadol, whereupon blood samples were drawn at 17 occasions. Enantiomer concentrations in whole blood were measured by LC-MS/MS and the CYP2D6,CYP2B6 and CYP3A4 genotype were determined, using the xTAG CYP2D6 Kit, pyrosequencing and real-time PCR, respectively. A positive correlation between the (+)/(-)-enantiomer ratio and time following drug administration was shown for all four enantiomer pairs. The largest increase in enantiomer ratio was observed for N-desmethyltramadol in CYP2D6 extensive and intermediate metabolizers, rising from about two to almost seven during 24 hours following drug intake. CYP2D6 poor metabolizers showed metabolic profiles markedly different from the ones of intermediate and extensive metabolizers, with large area under the concentration curves (AUCs) of the N-desmethyltramadol enantiomers and low corresponding values of the O-desmethyltramadol and N,O-didesmethyltramadol enantiomers, especially of the (+)-enantiomers. Homozygosity of CYP2B6 *5 and *6 indicated a reduced enzyme function, although further studies are required to confirm it. In conclusion, the increase in enantiomer ratios over time might possibly be used to distinguish a recent tramadol intake from a past one. It also implies that, even though (+)-O-desmethyltramadol is regarded the enantiomer most potent in causing adverse effects, one should not investigate the (+)/(-)-enantiomer ratio of O-desmethyltramadol in relation to side effects without consideration for the time that has passed since drug intake.

Synthetic cannabinoids are a group of psychoactive drugs presently widespread among drug users in Europe. Analytical methods to measure these compounds in urine are in demand as urine is a preferred matrix for drug testing. For most synthetic cannabinoids, the parent compounds are rarely detected in urine. Therefore urinary metabolites are needed as markers of drug intake. AB-FUBINACA was one of the top three synthetic cannabinoids most frequently found in seizures and toxicological drug screening in Sweden (2013-2014). Drug abuse is also reported from several other countries such as the USA and Japan. In this study, 28 authentic case samples were used to identify urinary markers of AB-FUBINACA intake using liquid chromatography quadrupole tandem time of flight mass spectrometry and human liver microsomes. Three metabolites suitable as markers of drug intake were identified and at least two of them were detected in all but one case. In total, 15 urinary metabolites of AB-FUBINACA were reported, including hydrolxylations on the indazole ring and the amino-oxobutane moiety, dealkylations and hydrolysis of the primary amide. No modifications on the fluorobenzyl side-chain were observed. The parent compound was detected in 54% of the case samples. Also, after three hours of incubation with human liver microsomes, 77% of the signal from the parent compound remained. Copyright © 2015 John Wiley & Sons, Ltd.

The analgesic drug tramadol and its metabolites are chiral compounds, with the (+)- and (-)-enantiomers showing different pharmacological and toxicological effects. This novel enantioselective method, based on LC-MS/MS in reversed phase mode, enabled measurement of the parent compound and its three main metabolites O-desmethyltramadol, N-desmethyltramadol and N,O-didesmethyltramadol simultaneously. Whole blood samples of 0.5g were fortified with internal standards (tramadol-(13)C-D3 and O-desmethyl-cis-tramadol-D6) and extracted under basic conditions (pH 11) by liquid-liquid extraction. Chromatography was performed on a chiral alpha-1-acid glycoprotein (AGP) column preceded by an AGP guard column. The mobile phase consisted of 0.8% acetonitrile and 99.2% ammonium acetate (20mM, pH 7.2). A post-column infusion with 0.05% formic acid in acetonitrile was used to enhance sensitivity. Quantitation as well as enantiomeric ratio measurements were covered by quality controls. Validation parameters for all eight enantiomers included selectivity (high), matrix effects (no ion suppression/enhancement), calibration model (linear, weight 1/X(2), in the range of 0.25-250ng/g), limit of quantitation (0.125-0.50ng/g), repeatability (2-6%) and intermediate precision (2-7%), accuracy (83-114%), dilution integrity (98-115%), carry over (not exceeding 0.07%) and stability (stable in blood and extract). The method was applied to blood samples from a healthy volunteer administrated a single 100mg dose and to a case sample concerning an impaired driver, which confirmed its applicability in human pharmacokinetic studies as well as in toxicological and forensic investigations.

The occurrence of structurally related synthetic cannabinoids makes the identification of unique markers of drug intake particularly challenging. The aim of this study was to identify unique and abundant metabolites of AKB-48 and 5F-AKB-48 for toxicological screening in urine. Investigations of authentic urine samples from forensic cases in combination with human liver microsome (HLM) experiments were used for identification of metabolites. HLM incubations of AKB-48 and 5F-AKB-48 along with 35 urine samples from authentic cases were analyzed with liquid chromatography quadrupole tandem time of flight mass spectrometry. Using HLMs 41 metabolites of AKB-48 and 37 metabolites of 5F-AKB-48 were identified, principally represented by hydroxylation but also ketone formation and dealkylation. Monohydroxylated metabolites were replaced by di- and trihydroxylated metabolites within 30 min. The metabolites from the HLM incubations accounted for on average 84% (range, 67-100) and 91% (range, 71-100) of the combined area in the case samples for AKB-48 and 5F-AKB-48, respectively. While defluorinated metabolites accounted for on average 74% of the combined area after a 5F-AKB-48 intake only a few identified metabolites were shared between AKB-48 and 5F-AKB-48, illustrating the need for a systematic approach to identify unique metabolites. HLMs in combination with case samples seem suitable for this purpose.

The objective of this study was to compare the performance of an immunoassay screening for synthetic cannabinoids with a newly developed confirmation method using liquid chromatography quadrupole time-of-flight mass spectrometry. The screening included metabolites from JWH-018, JWH-073, and AM-2201. The confirmation included metabolites from AM-2201, JWH-018, JWH-019, JWH-073, JWH-081, JWH-122, JWH-210, JWH-250, JWH-398, MAM-2201, RCS-4, and UR-144. The immunoassay was tested and found to have no cross-reactivity with UR-144 metabolites but considerable cross-reactivity with MAM-2201 and JWH-122 metabolites. Sensitivity and specificity for the immunoassay were evaluated with 87 authentic urine samples and found to be 87 % and 82 %, respectively. With a cutoff at 2 ng/ml, the confirmation showed 80 positive findings in 38 cases. The most common finding was JWH-122 5-OH-pentyl, followed by JWH-018 5-OH-pentyl. There were 9 findings of UR-144 metabolites and 3 of JWH-073 metabolites. In summary, the immunoassay performed well, presenting both high sensitivity and specificity for the synthetic cannabinoids present in the urine samples tested. The rapid exchange of one cannabinoid for another may pose problems for immunoassays as well as for confirmation methods. However, we consider time-of-flight mass spectrometry to be superior since new metabolites can be quickly included and identified.

A liquid chromatography/time-of-flight mass spectrometry (LC-TOF-MS) method for targeted toxicological screening in human postmortem blood samples from forensic autopsy cases has been developed, validated and compared with a previously used method using gas chromatography with nitrogen-phosphorus detection (GC-NPD). Separation was achieved within 12 min by high-resolution gradient chromatography. Ions were generated in positive and negative electrospray ionization mode and were detected in 2-GHz single mass spectrometry mode, m/z range 50-1,000. Before injection, 0.25 g blood was prepared by protein precipitation with 500 mu L of a mixture of acetonitrile and ethanol containing deuterated internal standards. An in-house database comprising 240 drugs and metabolites was built by analysing solutions from certified standards or other documented reference material available. Identification was based on scoring of retention time, accurate mass measurement and isotopic pattern. Validation was performed on spiked blood samples and authentic postmortem blood samples. The thresholds defined as minimum required performance levels were for most compounds in the range from 0.01 to 0.10 mu g/g. Typically, a mass error of less than 2 ppm and a precision of area measurements of less than 5 % coefficient of variation were achieved. Positive identification was confirmed at concentrations up to 500 mu g/g. Most compounds were determined in positive ionization mode, but for a limited number of compounds (fewer than 4 %) negative ionization was needed and a few early-eluted compounds could not be identified owing to substantial influence of interferences from the matrix and were thus not included in the screening. A robust and valid toxicological screening by LC-TOF-MS for postmortem blood samples, covering 50 % more compounds, and with higher precision and sensitivity than the previously used screening by GC-NPD was achieved.

A high-performance liquid chromatography method capable of measuring thiopurine mono-, di-, and triphosphates separately in red blood cells (RBCs) was developed. RBCs were isolated from whole blood using centrifugation. Proteins were precipitated using dichloromethane and methanol. The thioguanine nucleotides (TGNs) were derivatised using potassium permanganate before analysis. Analytes were separated by ion-pairing liquid chromatography using tetrabutylammonium ions and detected using UV absorption and fluorescence. The method was designed for use in clinical trials. Ten patient samples were analysed to demonstrate clinical application and to establish pilot ranges for all analytes. less thanbrgreater than less thanbrgreater thanThe method measured thioguanosine mono-(TGMP), di-(TGDP), and triphosphate (TGTP), as well as methylthioinosine mono- (meTIMP), di- (meTIDP) and triphosphate (meTITP) in RBCs collected from patients treated with thiopurine drugs (azathioprine, 6-mercaptopurine, and 6-thioguanine). less thanbrgreater than less thanbrgreater thanLOQ was 0.3, 3, 2, 30, 30 and 40 pmol/8 x 10(8) RBC, for TGMP, TGDP, TGTP, meTIMP, meTIDP and meTITP, respectively. Between-day precision were below 14% for all analytes at all concentrations and samples were stable at 4 degrees C for 8 h after sampling.