PF-04217903 optimization was the eluting L Solvents were preconditioned

Methanol or methanol / formic Acid has strong R Ability, a number of chemicals in the sample extract to extract not only the target compounds, but also other polar impurities. These contaminants can k Erh Hen the difficulty of the purification step, St Of the matrix changes for the analysis of target compounds, thereby improving the accuracy PF-04217903 of the instrumental analysis. We also found four other L Solvent Similar extraction efficiency. Given the toxicity of t L of solvents And ease of use, was added ethyl acetate as Extraktionsl Hlt solvent for the sludge sample weight. 3.2.2. Mud weight optimization by optimizing Extraktionsl Solvents, we have not reached the desirable recoveries for all target compounds due to the complexity of t of sludge samples, which contain large E amounts of other impurities.
To reduce the interference of impurities, the weight of the sludge were tested with 0.5 g, 1.0 g and 2.0 g of freeze-dried sludge. All samples were incubated with 200 ng of each analyte doped and extracted with 25 ml of ethyl acetate as above. The results showed that 24, 24 and 14 of the 28 analytes freeze-dried within the range of 70 120% recovery for 0.5 gg, 1.0 g, 2.0 mud fell, respectively. Obviously, lower weight of the sludge sample was better yields of target compounds. Therefore decided the optimized extraction procedures for sludge samples 0.5 g of freeze-dried slurry with 25 ml of ethyl acetate as L Solvent from the extract. 3.3. Optimization of cleaning to St Changes to reduce impurities in the samples, a cleaning is necessary prior to analysis by LC-MS / MS, especially in complex matrices such as key Strains.
In some previous studies, silica gel was applied in the cleaning step. To be an effective method for the purification of Kl Rschlamm or develop extracts, were self-made silica gel cartridges used in this study. In the cleaning step, the Elutionsl Solvent is most important parameters. The best Elutionsl Solvents should be able to elute the target compounds have good recoveries, and reduce st Rende compounds and substances of the matrix. In this test optimization was the eluting L Solvents were preconditioned by doping with 100 ng of analytes with silica gel cartridges which had been with 5 ml of methanol 5 ml of eluent selected Hlt optimized and, where 5 ml of hexane.
Th the polarity of the target compounds are very variable, ranging from high to medium polarity polarity t t: Of the glucocorticoid, androgen, Estrogens and progestins. For this reason, five eluent, ethyl acetate, ethyl acetate / methanol, ethyl acetate / methanol, ethyl acetate / methanol, and the ethyl acetate / methanol were tested for use in the cleaning step. The results showed relatively good recoveries of androgens and progestins with five selected Hlten get eluent. Recoveries of glucocorticoid Of estrogen and solvents varies between the different L. The glucocorticoid By not be eluted by ethyl acetate from the cartridges silica gel at all, suggesting that glucocorticoids A polarity T of L ben Solvent by Relative term h Ago as the acetate ethyl. It was found that ethyl acetate / methanol as eluent gave the best recoveries for target compounds, with the exception of DES, with 50.9%. Thus, the ethyl acetate / methanol as the eluent in the cleaning step selected Hlt