Testosterone detection

Figure 3.19. Comparison of S/N for glucuronide metabolite of testosterone detected using different IDA survey scans.

Detection and result The chromatograms were freed from mobile phase (stream of cold air), immersed in the reagent solution for 20 s, then dried in the air and finally kept at room temperature for 20 min. Testosterone (hRf 35—40) fluoresced pale blue in long-wavelength UV light (2 = 365 nm. Fig. 1). 

In situ quantitation The chromatogram was then dipped into liquid paraffin — -hcxanc (10 + 20) to increase the intensity of the fluorescence by a factor of ten and to stabilize it. The detection limit for testosterone is less than 500 pg per chromatogram zone (X c = 365 nm Xn > 430 nm). 

Detection with phosphoric acid at room temperature (with no heating afterwards) is specific for trenbolone, since related steroids such as progesterone and testosterone do not interfere under these conditions [12]. 

A -3-Ketosteroids, e.g. testosterone and epi-testosterone in urine I80°C, 20 min Pale blue induced fluorescence (Xfl = 440 nm) for A -3-ketosteroids, detection limit 5 ng. 

A -3-Ketosteroids, e.g. triraethylsilyl- testosterone I80°C, 20 min or 150°C, 20 min Conversion of AC3-ketosteroids or [ their trimethylsilyl or acetyl derivatives in fluorescent components, whereby the detection limits were improved by 65% for the acetates. A -3-keto- and A -3-OH-steroids also react with the same sensitivity. 

Males also depend on testosterone for olfactory performance. If in hamsters testosterone is converted to estrogen by subcutaneous silastic implants of the aromatase inhibitor l,4,6-androstatriene-3,17-dione, their sexual sniffing decreases. They sniff less toward novel females and no longer discriminate between males and females (Steel and Hutchinson, 1987). Castration affects odor detection performance in male rats (Doty and Ferguson-Segall 1989). 

One of the most interesting aspects of the changes in a-D-man-nosidase activity known to occur in vivo is the possible relationship with changes in zinc concentration in the tissues. In the case of rat epididymis, changes in enzyme activity have been monitored in parallel with measurements of zinc content.26 There was a positive correlation between the two variables, as both increased with age. The drop in a-D-mannosidase activity resulting from orchidectomy was accompanied by a 4-fold fall in the zinc content of epididymis, but the restoration of enzyme activity produced by subsequent injection of testosterone was not reflected in a detectable rise in the proportion of zinc. 

In their studies, Kushnir and co-workers [44, 45] found an increase in sensitivity of ESI detection of testosterone and adrenal steroids when they convert carbonyl groups to oximes. The steroid mixture is dissolved in 300 pi of an aqueous hydroxylamine solution (1.5 mol, pH 10), and following heating for 30 min at 90 C the derivatives are extracted with methyl t-butyl ether (2 ml). 

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