Ambient ionization mass spectrometry allows for analysis of samples in their natural state, i.e., with no sample pre-treatment. It can be viewed as a fast, simple, and economical analysis, but its main disadvantages include a lower analytical performance due to the presence of complex sample matrix and the lack of chromatographic separation prior to the introduction of the sample into the mass spectrometer. Here we present an application of two ambient ionization mass spectrometry techniques, i.e., Desorption Atmospheric Pressure Photoionization and Dielectric Barrier Discharge Ionization, for the analysis of known Selective Androgen Receptor Modulators, which represent common compounds of abuse in professional and semiprofessional sport. Eight real samples of illegal food supplements, seized by the local law enforcement, were used to test the performance of the ambient mass spectrometry and the results were validated against a newly developed targeted LC-UV-MS/MS method performed in multiple reaction monitoring mode with an external calibration for each analyte. In order to decide whether or not the compound can be declared as present, we proposed a system of rules for the interpretation of the obtained spectra. The criteria are based on mass spectrum matching (5-10 ppm accuracy from the theoretical exact mass and a correct isotopic pattern), duration of the mass signal (three or five consecutive scans, depending on the instrumentation used), and intensity above the background noise (threefold increase in intensity and absolute intensity above 5E4 or 1E5, depending on the instrumentation). When applying these criteria, good agreement was found between the tested methods. Ambient ionization techniques were effective at detecting SARMs at pharmacologically relevant doses, i.e., approximately above 1 mg per capsule, although they may fail to detect lower levels or isomeric species. It is demonstrated that when adhering to a set of clear and consistent rules, ambient mass spectrometry can be employed as a qualitative technique for the screening of illegal SARMs with sufficient confidence and without the necessity to perform a regular LC-MS analysis.
- MeSH
- androgenní receptory * metabolismus MeSH
- antagonisté androgenních receptorů analýza MeSH
- chromatografie kapalinová metody MeSH
- doping ve sportu prevence a kontrola MeSH
- hmotnostní spektrometrie metody MeSH
- lidé MeSH
- odhalování abúzu drog metody MeSH
- potravní doplňky analýza MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Synthesis of [15 N4 ] purine labeled cytokinine glycosides derived from zeatins and topolins containing a 9-β-d, 7-β-d-glucopyranosyl, or 9-β-d-ribofuranosyl group is described. These N6 -substituted adenine derivatives are intended as internal analytic standards for phytohormone analysis. All labeled compounds were prepared from 6-chloro[15 N4 ]purine (1). The equilibrium reaction of 1 with acetobromo-α-d-glucose gave isomeric 7-β-d (3) and 9-β-d (4) chloro glucosyl precursors, which were treated with the corresponding amines to get desired labeled cytokinin 7-β-d (6) and 9-β-d (5) glucopyranosides. Cytokinins containing 9-β-d-ribofuranosyl group (8) were obtained by direct enzymatic transglycosylation reaction of cytokinins (7) prepared from 6-chloro[15 N4 ] purine (1).
- Publikační typ
- abstrakt z konference MeSH
Cytokinins (CKs) are pivotal plant hormones that have crucial roles in plant growth and development. However, their isolation and quantification are usually challenging because of their extremely low levels in plant tissues (pmol g-1 fresh weight). We have developed a simple microscale magnetic immunoaffinity-based method for selective one-step isolation of CKs from very small amounts of plant tissue (less than 0.1 mg fresh weight). The capacity of the immunosorbent and the effect of the complex plant matrix on the yield of the rapid one-step purification were tested using a wide range of CK concentrations. The total recovery range of the new microscale isolation procedure was found to be 30-80% depending on individual CKs. Immunoaffinity extraction using group-specific monoclonal CK antibodies immobilized onto magnetic microparticles was combined with a highly sensitive ultrafast mass spectrometry-based method with a detection limit close to one attomole. This combined approach allowed metabolic profiling of a wide range of naturally occurring CKs (bases, ribosides and N9 -glucosides) in 1.0-mm sections of the Arabidopsis thaliana root meristematic zone. The magnetic immunoaffinity separation method was shown to be a simple and extremely fast procedure requiring minimal amounts of plant tissue.
- MeSH
- cévní protézy MeSH
- chirurgická rána * terapie MeSH
- hojení ran MeSH
- infekce v ráně * terapie MeSH
- lidé středního věku MeSH
- lidé MeSH
- pooperační komplikace terapie MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- terapie ran pomocí řízeného podtlaku * metody MeSH
- výkony cévní chirurgie MeSH
- výsledek terapie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
Předkládáme kasuistiku 77leté pacientky s tandemovou stenózou karotidy diagnostikovanou až peroperačně. Přestože byla před výkonem provedena standardní CT angiografie, druhá stenóza distálně od karotické bifurkace nebyla zobrazena. Žádná doporučení nebo guidelines týkající se léčby tandemové stenózy neexistují. Tandemová stenóza zůstává nevyřešeným problémem v cévní chirurgii.
We report a case of a 77-year-old patient with a tandem carotid stenosis diagnosed intraoperatively. Even though standard computed tomography angiography was performed before surgery, second stenosis distal to carotid bifurcation had not been detected. No recommendations or guidelines for managing tandem stenosis are available. It remains an unsolved issue in vascular surgery.
- MeSH
- arteria carotis interna chirurgie patologie MeSH
- disekce arteria carotis interna etiologie farmakoterapie radiografie ultrasonografie MeSH
- hodnocení rizik MeSH
- karotická endarterektomie * MeSH
- lidé MeSH
- peroperační komplikace etiologie radiografie ultrasonografie MeSH
- počítačová rentgenová tomografie MeSH
- recidiva MeSH
- senioři MeSH
- stenóza arteria carotis * diagnóza etiologie chirurgie radiografie ultrasonografie MeSH
- tranzitorní ischemická ataka etiologie prevence a kontrola MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
