ABSTRACT
A 24-year-old man known to consume illegal drugs was found dead in his apartment. A reclosable plastic zipper bag containing several hundred milligrams of a brown powder was found close to the dead body and the first assumption of the investigators was death due to heroin intoxication. Therefore, a legal autopsy was ordered. The following toxicological analysis revealed ocfentanil in urine and in the brown powder. Four different approaches for the determination of the ocfentanil concentrations in peripheral whole blood are described. Enrichment of ocfentanil from the powder was realized. With this reference, it was possible to determine the ocfentanil concentration in the seized powder to be 0.91%. Concentrations of ocfentanil were also determined in the sampled body fluids using the standard addition procedure. In peripheral blood 9.1 µg/L, in heart blood 27.9 µg/L and in urine 480 µg/L were measured. In addition, the antidepressant citalopram, the neuroleptic quetiapine and cannabinoids were found in urine and subsequently quantified in peripheral blood.
Subject(s)
Autopsy , Citalopram/toxicity , Illicit Drugs/toxicity , Piperidines/toxicity , Acetaminophen/blood , Acetaminophen/toxicity , Acetaminophen/urine , Body Fluids/chemistry , Calibration/standards , Cannabinoids/blood , Cannabinoids/toxicity , Cannabinoids/urine , Chromatography, High Pressure Liquid , Citalopram/blood , Citalopram/urine , Gas Chromatography-Mass Spectrometry/methods , Humans , Illicit Drugs/blood , Illicit Drugs/urine , Male , Piperidines/blood , Piperidines/urine , Quetiapine Fumarate/blood , Quetiapine Fumarate/toxicity , Quetiapine Fumarate/urine , Spectrometry, Mass, Electrospray Ionization , Tandem Mass Spectrometry , Young AdultABSTRACT
Bose-Einstein condensation has been achieved in a magnetic surface microtrap with 4 x 10(5) (87)Rb atoms. The strongly anisotropic trapping potential is generated by a microstructure which consists of microfabricated linear copper conductor of widths ranging from 3 to 30 microm. After loading a high number of atoms from a pulsed thermal source directly into a magneto-optical trap the magnetically stored atoms are transferred into the microtrap by adiabatic transformation of the trapping potential. In the microtrap the atoms are cooled to condensation using forced rf-evaporation. The complete in vacuo trap design is compatible with ultrahigh vacuum below 2 x 10(-11) mbar.
ABSTRACT
In this technical note we describe the setup and application of automated sample preparation and usage of flow-through NMR equipment for the characterization of ligand binding on proteins. In addition, we focus on the perspectives of automated analysis of 2D HSQC spectra to identify changes in patterns indicative for ligand binding or changes of sample conditions. In this context we discuss a combination of statistical and non-statistical data analysis.
Subject(s)
Nuclear Magnetic Resonance, Biomolecular/methods , Proteins/chemistry , Amines/metabolism , Binding Sites , Electronic Data Processing , Equipment Design , Equipment Failure , Humans , Hydrogen-Ion Concentration , Ligands , Nitrogen Isotopes , Protein Binding , Proteins/metabolism , Reference Standards , SolubilityABSTRACT
This paper presents the application of directly coupled capillary high-performance liquid chromatography (capillary HPLC) and proton high-field nuclear magnetic resonance spectroscopy (NMR) for structural elucidation of a so-far unknown kitol isomer. One- and two-dimensional continuous- and stopped-flow NMR spectra were recorded in a 180 µm i.d. capillary, corresponding to a detection volume of only 200 nL. Unequivocal structural assignment on the basis of 1D and 2D stopped-flow capillary HPLC-NMR experiments was performed. The kitol isomer mixture was present in a sample of thermally isomerized retinyl acetate and separated on a capillary column.
ABSTRACT
Coupling HPLC and NMR is one of the most powerful techniques for simultaneous separation and structural elucidation of unknown compounds in mixtures. To date, however, minimizing the detection volume, as is required when coupling NMR with miniaturized separation techniques, has been accompanied by a dramatic loss in resolution of the NMR spectra. Here, we report on the coupling of gradient capillary HPLC with on-column, high-resolution NMR detection. On-line stopped-flow and static (1)H NMR spectra were acquired with capillary columns of 75-315 µm i.d. With detection over a length of 1.2 cm, cell volumes cover a range of 50-900 nL. An on-line-detected NMR separation of dansylated amino acids was carried out in a 315 µm i.d. fused silica capillary packed to a length of 12 cm with C(18) stationary phase. The low solvent consumption makes the use of fully deuterated solvents economically feasible. NMR spectra with resolution on the order of 3 Hz were obtained using a 50 nL detection cell to measure 1.1 nmol of dansylated γ-aminobutyric acid under static conditions in a 75 µm i.d. capillary.
