O2110911 12 1383 5 74 6O CH 321CH 318 20171614 15ORMONOIDI PROGESTATIVIScheletro comune:19-nor-4-pregnen-3,20-dione (19 nor-progesterone)(17b-acetil-D4-estren-3-one)NomeProgesterone11-DeidroprogesteroneMedrisone17-IdrossiprogesteroneFlurogestoneMedrossiprogesteroneFlumedrossoneFluorometoloneMegestroloClormadinoneCiproteroneMedrogesteroneDidrogesteroneGestonorone10CH 3CH 3CH 3CH 3CH 3CH 3CH 3CH 3CH 3CH 3CH 3CH 3-CH 3-17---OHOHOHOHOHOHOHOHCH 3-OHD-11-----166666-6---CH 3---CH 3-CF 3-CH 3CH 3ClClCH 3--9 11- -- -- b-OH- --F b-OH- -- --F b-OH- -- -1,2--metilen- -- -- -UsoProgest. (acetato). AntiemicranicoAntiflogisticoProgest. . (retro-steroide)Progest.
The % citric acid acetonitrile system on HybridSPE-Phospholipid plates gave excellent analyte recovery and high efficiency phospholipid removal from the plasma samples. This study shows that there are simple and effective approaches to take when faced with particularly difficult analytes. In the example presented here, initially poor recovery of chelating steroid compounds in the formic acid system was overcome using a citric acid system that eliminated chelation interactions. The method gave high recovery and low variability of all tested steroids from both standard solutions and spiked plasma samples. The citric acid system was also very effective in removal of endogenous phospholipids from the matrix. In conclusion, with slight modification of the generic protocol, HybridSPE-Phospholipid was shown to be effective at matrix reduction while providing excellent recovery of difficult, chelating analytes. HybridSPE-Phospholipid is a simple and effective LC/MS sample prep technique for reducing matrix effects in LC/MS analysis of biological samples.