Automatic MDSPE Combined with DART-HRMS for the Rapid Quantitation of 21 Synthetic Cathinones in Urine.

A new, rapid, and automated method for the quantitation of 21 synthetic cathinones in urine was established using magnetic dispersive solid-phase extraction (MDSPE) in combination with direct analysis in real time-high-resolution mass spectrometry (DART-HRMS). Sample preparation and quantitation were verified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Methcathinone-D3, α-PVP-D8, and proadifen (SKF525A) were used as internal standards. Magnetic HLB extractant and NaH2PO4/NaOH buffer (0.2 M, pH 7) were used in automatic MDSPE. All 21 synthetic cathinones could be detected and analyzed by DART-HRMS in under 1 min. It was proven that the linearities of 21 synthetic cathinones were suitable (R2 > 0.99) in the concentration ranges of 0.5-100 ng/mL or 1-100 ng/mL. The precision and accuracy values were all within ±15%, and the samples were stable under various conditions. The average time of each sample from preprocessing to completion of detection was approximately 2 min, allowing for rapid sample analysis. The relative error (RE) of the concentrations obtained by DART-HRMS and LC-MS/MS were within ±13.61%, and the linear coefficient (R) was 0.9964. The results of DART-HRMS and LC-MS/MS provided equivalent values at the 95% confidence level. In summary, a simple, fast, and convenient quantitation method via DART-HRMS was established. This application can be utilized to reduce backlogs and promote rapid case processing.

Improved liquid-liquid extraction by modified magnetic nanoparticles for the detection of eight drugs in human blood by HPLC-MS.

Magnetic nanoparticles modified with porous titanium dioxide were used as clean-up nanospheres for the detection of eight drug poisons in human blood by high-performance liquid chromatography-mass spectrometry. The magnetic clean-up nanospheres (Fe3O4@mTiO2) with a mesoporous structure were successfully synthesized and characterized by scanning electron microscopy/energy dispersive spectroscopy, transmission electron microscopy, X-ray diffractometry, vibrating sample magnetometry, infrared spectroscopy, and Brunauer-Emmett-Teller techniques. Lipid co-extractives, such as phosphatidic acid and fatty acids, which are major interferences in HPLC-MS analysis causing ion suppression in the MS spectra of blood, could be efficiently removed by Fe3O4@mTiO2 based on the Lewis acid-Lewis base interactions. Following the optimization of the quantities of Fe3O4@mTiO2, the method was applied to the determination of eight drugs in spiked blood. The analytical ranges typically extended from 2 to 500 ng mL-1, and the recoveries ranged from 79.5-99.9% at different concentrations of blood. The limits of quantitation for drug poisons were 0.14-1.03 ng mL-1, which makes the method a viable tool for drug poison monitoring in blood.

Comparison of the Detection Windows of Heroin Metabolites in Human Urine Using Online SPE and LC-MS/MS: Importance of Morphine-3-Glucuronide.

Heroin abuse is a serious problem that endangers human health and affects social stability. Though often being used as confirmation of heroin use, 6-monoacetylmorphine (6-MAM) has limitations due to its short detection window. To compare the detection windows of heroin metabolites (morphine (MOR), 6-MAM, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G)) in human urine, an automated online solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and fully validated. The limits of detections (LODs) of the four metabolites were in the range of 1.25-5 ng/mL. Intra and inter-day precision for all the metabolites was 0.4-6.7% and 1.8-7.3%, respectively. Accuracy ranged from 92.9 to 101.7%. This method was then applied to the analysis of urine samples of 20 male heroin abusers. M3G was detected 9-11 days after admission to the drug rehabilitation institute in 40% of heroin users while MOR or M6G was not always detected. The detection window of M3G was thus the longest. Furthermore, M3G had a much higher concentration than MOR and M6G. Therefore, M3G could provide diagnostic information with regard to heroin exposure in the combination with other clues (e.g., heroin seizures at the scene).

Simultaneous chiral analysis of amphetamine-type stimulants and ephedrine by capillary electrophoresis coupled to time-of-flight mass spectrometry.

This study focused on the chiral characteristics of methamphetamine seizures in Shanghai for inferring the synthetic pathways of drugs. Capillary electrophoresis coupled to time-of-flight mass spectrometry was used for simultaneous chiral separation of amphetamine-type stimulants and ephedrine, including S(+)-amphetamine/R(-)-amphetamine, S(+)-methamphetamine/R(-)-methamphetamine, (±)-MDA (3,4-methylenedioxyamphetamine), (±)-MDMA (3,4-methylenedioxymethamphetamine), (±)-MDEA (3,4-methylenedioxy-N-ethylamphetamine), d,l-N-ethylamphetamine, methylephedrine/methylpseudoephedrine, and 1S,2R(+)-ephedrine/(-)-ephedrine. The running buffer was 50-mM ammonium formate (pH 2.2 was adjusted by 1-M formic acid) containing 0.26% highly sulfated γ-cyclodextrin as the chiral selector. All enantiomers were well resolved within 40 minutes by capillary electrophoresis at 20 kV in an uncoated fused-silica capillary (50-µm I.D. × 375-µm O.D. × 90-cm length) and detected by micro time-of-flight mass spectrometry. Twenty seized methamphetamine samples were determined by the established method. They were classified into two groups through their chiral characteristics.

Rapid screening of abused drugs by direct analysis in real time (DART) coupled to time-of-flight mass spectrometry (TOF-MS) combined with ion mobility spectrometry (IMS).

Increasing in cases involving drugs of abuse leads to heavy burden for law enforcement agencies, exacerbating demand for rapid screening technique. In this study, atmospheric pressure ionization technologies including direct analysis in real time (DART) ion source coupled to a time-of-flight mass spectrometer (DART-TOF-MS)as well asdopant-assisted positive photoionization ion mobility spectrometry (DAPP-IMS) without radioactivity were utilized together as the powerful analytical tool for the rapid screening and identification of 53 abused drugs.The limits of detection (LOD) were 0.05-2µg/mL when using DART-TOF-MS and 0.02-2µg when using DAPP-IMS which could satisfy the actual requirement in forensic science laboratory. The advantages of this method included fast response, high-throughput potential, high specificity, and minimal sample preparation. A screening library of reduced mobility (K0), accurate mass of informative precursor ion ([M+H]+) and fragment ions was established respectively by employing a bench-top DAPP-IMS and TOF-MS in-source collision induced dissociation (CID) mode. Then the standardized screening procedure was developed with criteria for the confirmation of positive result. A total of 50 seized drug samples provided by local forensic laboratory we reanalyzed to testify the utility of the method. This study suggests that a method combing DART-TOF-MS and DAPP-IMS is promising for the rapid screening and identification of abused drugs with minimal sample preparation and absence of chromatography.

Magnetic dispersive solid-phase extraction based on modified magnetic nanoparticles for the detection of cocaine and cocaine metabolites in human urine by high-performance liquid chromatography-mass spectrometry.

An easy-to-handle magnetic dispersive solid-phase extraction procedure was developed for preconcentration and extraction of cocaine and cocaine metabolites in human urine. Divinyl benzene and vinyl pyrrolidone functionalized silanized Fe3 O4 nanoparticles were synthesized and used as adsorbents in this procedure. Scanning electron microscopy, vibrating sample magnetometry, and infrared spectroscopy were employed to characterize the modified adsorbents. A high-performance liquid chromatography with mass spectrometry method for determination of cocaine and its metabolites in human urine sample has been developed with pretreatment of the samples by magnetic dispersive solid-phase extraction. The obtained results demonstrated the higher extraction capacity of the prepared nanoparticles with recoveries between 75.1 to 105.7% and correlation coefficients higher than 0.9971. The limits of detection for the cocaine and cocaine metabolites were 0.09-1.10 ng/mL. The proposed magnetic dispersive solid-phase extraction method provided a rapid, environmentally friendly and magnetic stuff recyclable approach and it was confirmed that the prepared adsorbents material was a kind of highly effective extraction materials for the trace cocaine and cocaine metabolites analyses in human urine.

Sensitive, automatic method for the determination of diazepam and its five metabolites in human oral fluid by online solid-phase extraction and liquid chromatography with tandem mass spectrometry.

A novel and simple online solid-phase extraction liquid chromatography-tandem mass spectrometry method was developed and validated for the simultaneous determination of diazepam and its five metabolites including nordazepam, oxazepam, temazepam, oxazepam glucuronide, and temazepam glucuronide in human oral fluid. Human oral fluid was obtained using the Salivette(®) collection device, and 100 µL of oral fluid samples were loaded onto HySphere Resin GP cartridge for extraction. Analytes were separated on a Waters Xterra C18 column and quantified by liquid chromatography with tandem mass spectrometry using the multiple reaction monitoring mode. The whole procedure was automatic, and the total run time was 21 min. The limit of detection was in the range of 0.05-0.1 ng/mL for all analytes. The linearity ranged from 0.25 to 250 ng/mL for oxazepam, and 0.1 to 100 ng/mL for the other five analytes. Intraday and interday precision for all analytes was 0.6-12.8 and 1.0-9.2%, respectively. Accuracy ranged from 95.6 to 114.7%. Method recoveries were in the range of 65.1-80.8%. This method was fully automated, simple, and sensitive. Authentic oral fluid samples collected from two volunteers after consuming a single oral dose of 10 mg diazepam were analyzed to demonstrate the applicability of this method.

Determination of co-administrated opioids and benzodiazepines in urine using column-switching solid-phase extraction and liquid chromatography-tandem mass spectrometry.

Co-administration of opioids with benzodiazepines is very common around the world. A semi-automated method was developed for the determination of four opioids and two benzodiazepines as well as their metabolites (including glucuronide metabolites) in human urine, based on on-line column-switching-solid-phase extraction (CS-SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The CS-SPE was performed by loading 200µL of urine sample to an Oasis HLB cartridge. Detection was achieved using a LC-MS/MS system equipped with an electrospray ionization source (ESI). For unequivocal identification and confirmation, two selected reaction monitoring transitions were registered for each compound, and no co-elution of interferences was observed at the expected retention time. Significant ion suppressions were observed for most analytes during chromatographic runs, but isotope-labeled internal standards (ISs) were used and found to be useful to compensate for the determination error caused by the matrix effect. The assay's linearity ranged from 1-20ng/mL to 800-1000ng/mL for 23 compounds, except for lorazepam (LOR), whose linearity was in the range of 1-100ng/mL. This method showed to be precise and accurate. The relative standard deviation (RSD) % values of within-run precision, between-run precision and total precision were not greater than 10.4% (n=3), 12.9% (n=5) and 15.1% (n=15), respectively. Accuracy values were in the range of 87.5-110%. Limits of detection (LODs) ranged from 0.2ng/mL to 5ng/mL, and limits of quantification (LOQs) ranged from 1ng/mL to 20ng/mL. The method was applied to the assay of 12 samples from forensic cases, which exemplified the co-administration of benzodiazepines (BZDs) by some heroin abusers. This method was of high sensitivity, selectivity and reliability, minimum sample manipulation, semi-automation, and fairly high throughput (analysis time per sample was 20min). The method developed will be useful for the detection of co-administrated drugs and the study of the interactions of BDZs with opioids.

Identification and quantification of 34 drugs and toxic compounds in blood, urine, and gastric content using liquid chromatography with tandem mass spectrometry.

A liquid chromatography with tandem mass spectrometry method was developed for the simultaneous screening of 34 drugs and poisons in forensic cases. Blood (0.5 mL, diluted 1:1 with water) or 1.0 mL of urine was purified by solid-phase extraction. Gastric contents (diluted 1:1 with water) were treated with acetonitrile, centrifuged, and supernatant injected. Detection was achieved using a Waters Alliance 2695/Quattro Premier XE liquid chromatography tandem mass spectrometry system equipped with electrospray ionization, operated in the multiple reaction monitoring modes. The method was validated for accuracy, precision, linearity, and recovery. The absolute recovery of drugs and toxic compounds in blood was greater than 51% with the limit of detection in the range of 0.02-20 ng/mL. The absolute recovery of drugs and toxic compounds in urine was greater than 61% with limit of detection in the range of 0.01-10 ng/mL. The matrix effect of drugs and toxic compounds in urine was 65-117% and 67-121% in blood. The limit of detection of drugs and toxic compounds in gastric content samples were in the range of 0.05-20 ng/mL. This method was applied to the routine analysis of drugs and toxic compounds in postmortem blood, urine, and gastric content samples. The method was applied to actual forensic cases with examples given.

Screening of drugs of abuse and toxic compounds in human whole blood using online solid-phase extraction and high-performance liquid chromatography with time-of-flight mass spectrometry.

A novel method for the screening of 151 drugs of abuse and toxic compounds in human whole blood has been developed and validated by online solid-phase extraction with liquid chromatography coupled to time-of-flight mass spectrometry. Analytes were extracted and separated by using a fully automated online solid-phase extraction liquid chromatography system with total chromatographic run time of 26 min. Time-of-flight mass spectrometry screening of 151 drugs of abuse and toxic compounds was performed in a full-scan (m/z 50-800) mode using an MS(E) acquisition of molecular ions and fragment ions data at two collision energies (one was 6 eV and another one was in the range of 5-45 eV). The compounds were identified based on retention times and exact mass of molecular ions and fragment ions. The limit of detection ranged from 1 to 100 ng/mL and the recovery of the method ranged from 6.3 to 163.5%. This method is proved to be a valuable screening method allowing fast and specific identification of drugs in human whole blood.

Direct determination of diazepam and its glucuronide metabolites in human whole blood by µElution solid-phase extraction and liquid chromatography-tandem mass spectrometry.

A µElution solid-phase extraction (SPE) liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of diazepam, nordiazepam, oxazepam, oxazepam glucuronide, temazepam and temazepam glucuronide in human whole blood is presented. 200 µL of whole blood samples were loaded onto a Waters Oasis HLB 96-well µElution SPE plate using 75 µL of methanol as the elution solvent, and the eluents were injected into an Eclipse XDB C18 column. No hydrolysis, solvent transfer, evaporation or reconstitution was involved in the sample preparation procedures. Tandem mass spectrometric detection with Turbo Ion Spray was conducted via multiple reaction monitoring (MRM) under positive ionization mode. The method was validated and proved to be accurate (accuracy within 93-108%), precise (intra-day RSD<9.9% and inter-day RSD<7.2%) and sensitive with limits of detection (LOD) in the range of 0.05-0.25 ng/mL for all the compounds. Extraction recoveries were in the range of 31-80% for all the analytes. This method demonstrated to be reproducible and reliable. The applicability of the method was demonstrated by analysis of several forensic cases involving diazepam and its metabolites.

Determination of ecgonine and seven other cocaine metabolites in human urine and whole blood by ultra-high-pressure liquid chromatography-quadrupole time-of-flight mass spectrometry.

Ecgonine is suggested to be a promising marker of cocaine (COC) ingestion. A combined mass spectrometry (MS) and tandem MS (MS/MS) method was developed to simultaneously determine ecgonine and seven other metabolites of cocaine in human urine and whole blood with ultra-high-pressure liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The compounds were extracted from as little as 100 µL of sample by solid-phase extraction with a 96-well µElution solid-phase extraction plate. The protonated molecules or fragment ions at accurate mass acquired in MS mode were used to quantify specific analytes, following by dedicated MS/MS identification. The assay was linear in the range from 5 to 50-100 ng/mL for urine samples, except for ecgonine methyl ester (10-200 ng/mL) and ecgonine (40-400 ng/mL), and was linear from 1-2 to 50 ng/mL for whole blood samples, except for ecgonine methyl ester (20-1,000 ng/mL) and ecgonine (40-2,000 ng/mL). The correlation coefficients were all greater than 0.99. The limits of detection ranged from 0.2 to 16 ng/mL, and the lower limits of quantification ranged from 1 to 40 ng/mL. The repeatability and intermediate precision were 18.1% or less. The accuracy was in the range from 80.0 to 122.9%, process efficiencies were in the range from 8.6 to 177.4%, matrix effects were in the range from 28.7 to 171.0%, and extraction recoveries were in the range from 41.0 to 114.3%, except for ecgonine (12.8% and 9.3% at low and high concentrations, respectively). This method was highly sensitive in comparison with previously published methods. The validated method was successfully applied to the analysis of real samples derived from forensic cases, and the results verified that, on the basis of data from four positive samples, ecgonine is a promising marker of cocaine ingestion.