Mass spectroscopy Steroids

The field of steroid analysis includes identification of steroids in biological samples, analysis of pharmaceutical formulations, and elucidation of steroid stmctures. Many different analytical methods, such as ultraviolet (uv) spectroscopy, infrared (ir) spectroscopy, nuclear magnetic resonance (nmr) spectroscopy, x-ray crystallography, and mass spectroscopy, are used for steroid analysis. The constant development of these analytical techniques has stimulated the advancement of steroid analysis. 

In addition, a total of 146 sheep urine and 87 chicken muscle samples from birds sold in local markets and originating from Brazil, Denmark, France, and Turkey were tested for residues of diethylstilbestrol and ethinylestradiol (41). Although some of the samples were positive to both analytes by an immunochemical screening assay, confirmatory analysis by GC-mass spectroscopy (MS) showed that none of the samples contained residues of the examined steroids. 

Gaskell, Simon J., Analysis of Steroids by Mass Spectroscopy. 29 385... 

General and Selective Isolation Procedure for Gas Chromatography/Mass Spectroscopy Analysis of Steroids in Tissues and Body Fluids... 

Generally, the most powerful method for structural elucidation of steroids is nuclear magnetic resonance (nmr) spectroscopy. A definitive method for structural determination is x ray ciystallography. Extensive x-ray crystal structure determinations have been done on a wide variety of steroids. In addition, other analytical methods for steroid quantification or structure determination include, mass spectrometry, polarography, fhiorimeUy. radioimmunoassay, and various chromatographic techniques. 

Reepmeyer, J. C., Revelle, L. K., and Vidavsky, I. (1998), Detection of clobetasol propionate as an undeclared steroid in zinc pyrithione formulations by high-performance liquid chromatography with rapid-scanning ultraviolet spectroscopy and mass spectrometry. Journal of Chromatography A, Vol. 828, Number 1,18 December 1998, pp. 239-246(8). 

UV and fluorescent spectroscopy can be employed down to 190 nm because there is no solvent interference. Mass spectrometry is easy because the water provides good ionization. Flame ionization detection (FID) is of particular interest because potentially it offers a sensitive and universal detector. A number of different interfaces have been used, including heated capillaries, which have been examined by Miller and Hawthorne [62], Ingelse et al. [63], and others [64, 65], who separated a range of analytes including alcohols, amino acids, and phenols. An alternative method employing a cold nebuliza-tion of the eluent has been introduced by Bone et al. [66]. They were able to detect both aliphatic and aromatic alcohols, polymers, carbohydrates, parabens, and steroids. 

Scientists from the National Institutes of Health have isolated and determined the structures of many of the compounds present in these skin secretions using the techniques of mass spectrometry and NMR spectroscopy (Chapter 1 2). Thus far, the structures of close to 200 different alkaloids have been determined. The most potent of these toxins is batrachotoxin (from Phyllobates ter-rlbllls), an example of a steroidal alkaloid. Other toxins include... 

Compton BJ, Siuzdak G (2003) Mass spectrometry in nucleic acid, carbohydrate and steroid analysis. Spectroscopy 17 699-713... 

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