1,721,006 research outputs found
“Consumo de sustancias estimulantes y drogas de abuso en el deporte: la experiencia italiana. / Use of stimulants and drugs of abuse in the sport: the italian experience”.
No full textApplication of solid phase microextraction for the determination of stimulants, narcotics and other doping agents excreted free in urine
No full textApplication of solid-phase microextraction to antidoping analysis: Determination of stimulants, narcotics, and other classes of substances excreted free in urine
No full textThis paper describes the application of solid-phase microextraction
(SPME) with subsequent injection in a gas chromatograph–mass
spectrometer (GC–MS) (electron impact, full scan) for the
screening analysis of stimulants and narcotics in urine. Several
d i fferent kinds of fibers were preliminarily tested and
comparatively evaluated considering the influence on the overall
analytical performance of the method; other experimental
parameters; and, primarily among them, the volume of urine, the
pH value, and the time of adsorbtion. The optimal experimental
conditions have been recorded using 0.5 mL of urine with the pH
value adjusted to 10 with carbonate buffer, and in which is
immersed a polydimethylsiloxane/divinylbenzene fiber, with a
sampling time of 30 min; the fiber is then directly desorbed in the
injection port of the GC–MS equipment. All the analytes show a
good linearity (R2 > 0.99 for most substances) and a good
reproducibility at the concentration corresponding to the minimum
performance requirement limit or at the cut-off value fixed by the
World AntiDoping Agency (CV% < 11). The limit of detection of
the method is 50 ng/mL for the majority of the substances
investigated. Imidazole-based drugs (e.g., naphazoline) and local
anesthetics can also be included in this screening method.
Whenever necessary, confirmation analyses may also be performed
by following the same pre-chromatographic procedure. Integrating
the SPME process and the GC–MS analysis with a dedicated
autosampler that combines the microextraction and injection
capacities maximizes the overall analytical capacity of a single
GC–MS system and reduces the human labor necessary for and the
environmental impact of screening for stimulants and narcotics
excreted free in urine
Speeding up the analytical times: fast GC analysis for stimulants. Narcotics and drug of abuse.
No full textParallel analysis of stimulants in saliva and urine by gas chromatography/mass spectrometry: perspectives for "in competition" anti-doping analysis.
No full textStimulants are banned by the World Anti-Doping Agency (WADA) if used “in competition”.
Being the analysis of stimulants presently carried out on urine samples only, it might
be useful, for a better interpretation of analytical data, to discriminate between an early
intake of the substance and an administration specifically aimed to improve the sport
performance. The purpose of the study was to investigate the differences, in terms of
excretion/disappearance of drugs, between urine and oral fluid, a sample that can reflect
plasmatic concentrations.
Oral fluid and urine samples were collected following oral administration of the following
stimulants: modafinil (100 mg), selegiline (10 mg), crotetamide/cropropamide (50mg
each), pentetrazol (100 mg), ephedrine (12 mg), sibutramine (10 mg), mate de coca (a dose
containing about 3mg of cocaine); analysis of drugs/metabolites was carried out by gas
chromatography/mass spectrometry (GC/MS) in both body fluids.
Our results showthat both the absolute concentrations and their variation as a function of
time, in urine and in oral fluid, are generally markedly different, being the drugs eliminated
from urinemuch more slowly than from oral fluid. Our results also suggest that the analysis
of oral fluid could be used to successfully complement the data obtained from urine for “in
competition” anti-doping tests; in all those cases in which the metabolite(s) concentration
of a substance in urine is very low and the parent compound is not detected, it is indeed
impossible, relying on urinary data only, to discriminate between recent administrations of
small doses and remote administrations of higher doses
A rapid method for the extraction and enantiomeric separation of amphetamine-type stimulants
No full textUrinary concentrations of threshold substances: a clear enough discrimination between doping and therapy? The case of ephedrines
No full textDetermination of sildenafil, vardenafil and tadalafil metabolites in human urine by GC/MS
No full textDetection of sibutramine administration: A gas chromatography/mass spectrometry study of the main urinary metabolites
No full textA gas chromatographic/mass spectrometric (GC/MS) study aimed at identifying the metabolites of
sibutramine (1-(4-chlorophenyl)-N,N-dimethyl-a-(2-methylpropyl)cyclobutanemethanamine) in urine
is described. Urinary excretion of sibutramine metabolites following the oral administration
of a single dose of sibutramine was followed by GC/MS analysis. After identification of the
chromatographic signals corresponding to the six main urinary metabolites, the fragmentation
pattern was studied in electron ionization (EI) mode after derivatization to the corresponding
methyl and trimethylsilyl derivatives. Urine samples were pretreated according to a reference
procedure (liquid/liquid separation, enzymatic hydrolysis, pre-concentration under a stream of
nitrogen and derivatization, either under thermal incubation and by microwave irradiation). All
sibutramine metabolites were excreted as glucuroconjugates, and retain the chiral carbon present in
the sibutramine skeleton. The metabolites identified included mono-desmethylsibutramine (norsibutramine),
bi-desmethylsibutramine (nor-nor-sibutramine), and the corresponding hydroxylated
compounds, the hydroxylation taking place either on the cyclobutane or on the isopropyl chain. The
excretion profiles of the different metabolites were also evaluated. From an analytical point of view,
the method can be applied to different fields of forensic analytical toxicology, including anti-doping
analysis. Although the lack of certified reference materials does not allow a precise determination of
the limits of detection (LODs) of all the sibutramine metabolites, an estimation taking into account
the response factor of similar compounds ensures that all metabolites are still clearly detectable in a
range of concentrations between 10 and 50 ng/mL, thus satisfying the minimum required performance
limits (MRPLs) of the World Anti-Doping Agency (WADA)
- …
