Sensitivity anabolic steroids

In cases where specific anabolic steroids or their metabolites are suspected, and only I7a-hydroxy or 17(3-hydroxy compounds are to be tested for, the separation on the Sephadex LH-20 column may be omitted. Hydrolysis is carried out on the residue from the Sep-Pak cartridge, but this will yield somewhat dirtier residues with the possibility of a reduction in sensitivity. 

Owing to the greater sensitivity of PBC patients to pharmaceutical preparations, different pharmacons, e. g. phenothiazines, contraceptives, oestrogens and anabolic steroids, can reinforce cholestasis and the clinical symptoms, thus aggravating the course of disease. Gallstones are frequently detectable (35-40%) as a rule, they are pigment gallstones. Administration of clofibrate is con-... 

The main reasons for derivatization of steroids are to decrease heat sensitivity of steroids to avoid irreversible adsorption of steroids onto the stationary phase to increase volatihty of steroids to increase the separation efficiency to achieve enhanced selectivity of the separations, and to improve the sensitivity of the detectors. Segura et al. described some important general requirements for derivatization reactions, i.e., a single derivative should be formed for each analyte the reaction should be simple and rapid, and they should occur under mild conditions the derivate should be stable, reproducible, and produced with high yield in quantitative analyses, the calibration curve should be linear. The main derivatization method for steroids is silylation, but other derivatization methods using, for example, acetic acid anhydride, trifluoroacetic anhydride (TFA), pentafluoro-propionic acid (PFPA), or heptafluoroabutyric anhydride (HFBA) could also be used. " For anabolic steroids... 

Turning to the abuse of anabolic steroids by human competitors, Shackleton et al. (1997) conducted LC-MS analyses of pharmaceutical T esters in human plasma because of the potential applications to doping control, especially if sensitivity could be improved. 

This classic biological methodology is widely used in research, diagnosis, and testing because it is affordable and sensitive to tiny amounts of material. It is applied to domains such as the environment and agriculture (pesticides, anabolic steroids, aflatoxins, HPA) for which numerous assay kits exist. However only compounds for which there exist adapted antibodies and the conjugated enzymes can be measured. 

Steroids are hormones that are known to modulate DNA expression and protein expression. Adrenal hormones (e.g., aldosterone and cortisol) participate in the control of metabolism and of salt and water homeostasis. The other class of steroid hormones, gonadal hormones (e.g., estradiol, progesterone, and testosterone), influence mammalian sexual development and function. Several steroids also modulate neurotransmitter action, and some athletes have misused anabolic steroids to enhance their physical strength and performance. GC/MS has been used in conjunction with El or Cl as an ionization method for steroids to determine molecular mass, elemental composition, and length of the side chain of a steroid hydrocarbon. Although these techniques are highly sensitive, they require multistep derivatization of these thermally labile compounds. FAB-MS has proven to be a useful technique to analyze underivatized urinary... 

Srinivas and Srinivasulu (1993) found that heulandate layers developed with carbon disulfide-pyridine (1 1) were effective for the separation of steroid hormones,—dehydroepiandrosterone could easily be separated from mixtures of cholesterol and estradiol benzoate or testosterone phenylpropionate, and testosterone could be separated from mixtures of cholesterol and testosterone phenylpropionate or estradiol benzoate. Likewise, estradiol could easily be separated from mixtures of cholesterol and estradiol benzoate. Daeseleire et al. (1994) applied HPTLC and GC/MS for the detection of anabolic steroids used as growth promoters in illicit cattle fattening within the European market. Agrawal et al. (1995) developed a sensitive, reliable, and rapid silica gel TLC method for the separation, identification, and quantification of stereospecific androgen metabolites. 

In the present study the technique of GC-MS has been used as a means of identifying the anabolic drug in samples which have given a positive response to the radioimmunoassay test. These studies have necessitated (2) an investigation into the metabolism of the anabolic steroids most likely to be used in sport, and to establish the most specific and sensitive means of applying GC-MS methods. It has been important to retain in the method the capability of identifying metabolites of previously unencountered drugs. 

As has happened with GC-MS, there is a clear trend that the use of LC-MS, because of the increasing availability of robust and sensitive instruments, will be very common in the field of the analysis of growth promoters and endocrine disrupters. In many laboratories, LC-MS is used already to detect and identify anabolic steroids, corticosteroids, and p-agonists at low (Ag/L or lig/kg levels. Looking at multiresidue analysis, LC-MS will earn its position as a very useful technique. The development of quality criteria for LC MS, similar to the well-known criteria for GC-MS, for confirmatory analysis will certainly boost the possibilities for more general use. 

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