Determination of various steroids in normal adrenal glands and adrenocortical tumours by liquid chromatography/atmospheric pressure ionization mass spectrometry

Abstract

ions of seven steroids were clearly observed in chromatograms of biological samples. The ratio of glucocorticoid (cortisol) to mineralocorticoid (corticosterone) content was measured, and found to be significantly lower for aldosteronomas and higher for Cushing's adenomas than for normal adrenals. These findings indicate that the method had sufficient sensitivity for the identification and simultaneous measurement of a variety of adrenal gland steroids.

Stochastic dynamic mass spectrometric quantification of steroids in mixture

“…Therefore, compulsory there is needed an accurate, precise, selective and sensitive quantitative model equation connecting between the experimentally observed variables and the concentration of the analyte in solution. As presented throughout this paper as well as a more recent reference devoted to the same problem [40] our new formulas (5) and (6) provide adequate solution of this problem, showing a highly reliable quantification of four steroids in mixture at concentration level ng. (mL) -1 yielding to coefficient of correlation between theory and experiment |r| = 0.9981 9.…”

“…It is based on the approximation A i » <(I-<I>) 2 >. In this context, one important feature is the chemometric parameters obtained on the base on the linear approximation of the relationship D SD = f(D " SD ) depicted on the latter figure, where D " SD parameters are obtained according to equation (6). As can be seen A » 0 and B » 1.…”

“…Moreover, there is obtained excellent correlation using independent correlative analysis between mass spectrometric and chromatographic methods, which not only proofs but also validate our protocol based on the model formulas written above. The next persuasive example from the perspective of employment of equations (5) and (6) for the purposes of the analytical practice is the relation between the analyte concentration of (3) with respect to the observable MS intensity-values of the ion at m/z 297 quantified according to the latter model formulas (Figure 12.) There is obtained |r| = 0.9968. Again, the coefficient of correlation is improved comparing with the chemometric data on the correlation between the I TOT values and the concentration of the analyte in solution shown [40].…”

“…These facts have led to elaboration of protocols chiefly based on mass spectrometry. Despite, that the HPLC enable us to determine the D 4 -3-ketonic structure of STs by means of UV-detection, the D 5 -3-hydroxy structural unit in pregnenolone and dehydroepiandrosterone (Figure 1) can be determined only is means of HPLC with immobilized enzyme column [6], accounting for other fact that HPLC cannot identify unknown peaks. The frequently employed radioimmunoassay cannot be utilized to determine mixtures of STs despite its sensitivity.…”

Preclinical Cushing&rsquo;s Syndrome: Report of Four Cases and Analysis of Steroid Contents in Adenomas

“…However, there have been a few evaluations of steroid contents in tumors [6,[11][12][13]. Analyses of steroid contents in tumors by HPLC suggested that PCS may con sist of at least two subtypes: (type A) relatively small tumors which show a pattern of corticoid production very similar to that in overt Cushing's syndrome (cases 3 and 4); (type B) larger tumors, more than 4 cm in diameter by CT scan, which show corticoid production comparable to or less than that of normal adrenal gland (cases 1 and 2).…”