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.

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.

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.

Relationships Among Job Burnout, Generativity Concern, and Subjective Well-Being: A Moderated Mediation Model.

Background: Policemen all over the world are tasked with the heavy work of maintaining social security. With the imbalance in mentality brought about by high population density and social transformation, the work of the Chinese police is particularly hard. As the window of demographic dividend is closing and the number of newborns is insufficient, China has started to adjust its established fertility policy to encourage a family to have two children. However, the results have not met the expectations of the policy adjustment. It is generally believed that factors such as high work pressure, high parenting costs, and low levels of happiness may be the main reasons for low fertility intentions. Studying this typical population of police officers may explore the relationship between work stress, happiness, and reproductive concerns, and provide evidence of Chinese sample. Objectives: To explore the relations between job burnout, subjective well-being, and generativity concern in Chinese police officers. Methods: The study used a cross-sectional survey to collect data from 494 police officers from H city in China. The participants completed the Maslach Burnout Inventory (MBI), the Family Adaptability and Cohesion Scale (FACESII), the Loyola Generativity Scale (LGS), and the Satisfaction with life scale (SWLS). Moderated mediation effect models assessed the association between job burnout, subjective well-being, and generativity concern. Results: Job burnout had a significant negative predictive effect on both subjective well-being and generativity concern, and subjective well-being played a mediating role between job burnout and generativity concern. In addition, family intimacy and adaptability had a significant negative moderating effect between subjective well-being and generativity concern. In a conclusion, there is a moderated mediating effect between job burnout and generativity concern. Conclusion: Subjective well-being played a mediating role between job burnout and generativity concern.

[Preparation of lomefloxacin-Tb3+ nanoparticles modified by PVP via microwave-assistance and its properties of fluorescence].

Polyvinylpyrrolidone(PVP)-modified LFLX-Tb3+ nanoparticles were prepared by microwave radiation method. The obtained products were characterized by means of SEM, FTIR and fluorescence spectra. The surface-modified LFLX-Tb3+ nanoparticles showed a narrow size distribution and enhanced luminescence property compared with that of the unmodified ones. These results were attibuted to the surface passivation of the LFLX-Tb3+ nanoparticles by the PVP molecules. It is confirmed that the addition dosage of PVP is an important factor in the preparation of the LFLX-Tb3+ nanoparticles. The reasons for luminescence enhancement were discussed.

[Study on the interaction of lomefloxacin terbium complex and bovine serum albumin by fluorescence spectra].

Using lomefloxacin-terbium as a fluorescent probe, the interaction of LFLX-Tb3+ and bovine serum albumin (BSA) was investigated by fluorescence spectra. The interaction of LFLX and BSA is quite strong. LFLX can affect the conformation of BSA to some degree. Meanwhile, the electrostatic binding of the BSA with Tb3+ in LFLX-Tb3+ complex could decease the nonradiative energy loss through O-H vibration of H2O molecule in Tb3+ complex. Under the optimum conditions, BSA can enhance the fluorescence intensity of the lomefloxacin-terbium complex at 545 nm, and the enhanced fluorescence intensity of Tb3+ is proportional to the concentration of BSA. Based on that, a new method is constructed for the determination of BSA. The linear ranges for BSA are 16.5-148.5 microg x mL(-1) with a detection limit of 68.8 ng x mL(-1) and relative standard deviations of 1.4%. This method is simple, practical and relatively free of interference from coexistent substances.

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.

[Analysis of the association between the quantity of insoluble particles in intravenously administered solution with adverse drug reactions].

OBJECTIVE: To investigate the possible association between adverse drug reactions and the quantity of insoluble particles in the intravenously administered drugs. METHODS: The solutions were prepared following the procedures in routine clinical practice, and the quantity of insoluble particles in these solutions were measured before and after the solutions went through the transfusion apparatus. RESULTS: The quantity of insoluble particles measured after the solutions passed through the transfusion apparatus was consistent with the standard documented in Chinese Pharmacopoeia. CONCLUSION: Adverse intravenous reactions occurring in our hospital has no association with excessive quantity of insoluble particles in the administered drugs.

[Preparation of famotidine microemulsion and its quality evaluation].

OBJECTIVE: To study the preparation of famotidine microemulsion (FM) and its quality evaluation, thereby to establish the quality-control criteria for this preparation. METHODS: The formulations of the FM were optimized by studying the pseudoternary phase diagrams and its absorption in rat jejunum using in situ perfusion method. The morphology, particle size distribution, famotidine concentration and stability of the FM were studied. RESULTS: The optimization of formulation was completed successfully. Electron microscopy presented the FM as small spherical drops, with a mean diameter of 65 nm. The average recovery as determined by high-performance liquid chromatography was 97.63%, its mean RSD being 0.72%. CONCLUSION: The FM is easy to prepare with consistent quality, whose reliable determination method may be easily reproduced.

Extending the detection window of diazepam by directly analyzing its glucuronide metabolites in human urine using liquid chromatography-tandem mass spectrometry.

A method for the simultaneous direct analysis of diazepam oxazepam glucuronide, temazepam glucuronide, oxazepam, nordiazepam, and temazepam in human urine was developed and validated. Urine sample was purified by solid phase extraction (SPE), and the analysis was achieved using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) system equipped with an electrospray ionization source (ESI). Multiple reaction monitoring (MRM) mode was used to analyze the target compounds. Extraction recoveries were 65-122% for all the analytes. The method showed acceptable intra-assay and inter-assay precision (both relative standard deviation (RSD)≤11.2%) for quality control (QC) samples. The limits of detections (LODs) were in the range of 0.1-2 ng/mL. The present assay was applied to analyze the urine obtained from three volunteers after oral administration of a single dose 5mg of diazepam. The results showed that, the detection periods of oxazepam glucuronide and temazepam glucuronide were much longer than diazepam and other metabolites.