Compound vortex controlled

Most samples may be prepared by dissolution in water. The final concentration should be optimized according to the aim of the analysis, counterion or impurity analysis. For the control of impurities, the main counterion may be fairly overloaded. This may have an impact on the ionic strength of the sample and will produce a disturbed peak profile for the main compound. When solubility problems are encountered, up to 30% of methanol, ethanol, or acetonitrile may be added to improve solubility. However, the presence of too much organic solvent may produce an instrumental error, because the conductivity of the sample plug will differ too much from BGE conductivity, leading to current leakage. Or, when the sample is insoluble in water, it may be suspended, vortexed, and then centrifuged. The analysis is then performed on the supernatant as the ions are water soluble. 

Indeed, these reactions play an important role in the Antarctic ozone hole and they have important implications for control strategies, particularly of the bromi-nated compounds. For example, Danilin et al. (1996) examined the effects of ClO -BrO coupling on the cumulative loss of O-, in the Antarctic ozone hole from August 1 until the time of maximum ozone depletion. Increased bromine increased the rate of ozone loss under the denitrified conditions assumed in the calculations by converting CIO to Cl, primarily via reactions (31b) and (31c) (followed by photolysis of BrCl). Danilin et al. (1996) estimate that the efficiency of ozone destruction per bromine atom (a) is 33-55 times that per chlorine atom (the bromine enhancement factor ) under these conditions in the center of the Antarctic polar vortex, a 60 calculated as a global average over all latitudes, seasons, and altitudes (WMO, 1999). 

Antifungal bioassay. Known amounts of the pure test compounds were dissolved in DMSO and serial dilutions prepared in the same solvent. A 20 1 aliquot of each solution was mixed with 2 ml of Emmons liquid medium seeded with ca. 2 X 10 CFU/ml of the test organism. The inoculated tubes were vortexed and incubated at 26 C. Similarly, inoculated tubes without test compounds served as controls. Depending on the growth characteristics of the test species, results were recorded after 2-4 days. The lowest concentration of the test compound that totally inhibited growth of test organism was recorded as the minimum inhibitory concentration (MIC) for that species. 

Small molecules Make stock solutions in DMSO (20-100 mM depending upon solubility). For yeast medium containing compounds, such as a positive control compound for an assay or HTS, place an Eppendorf tube containing medium into a beaker of boiling water and turn off heat. After 30 s to 1 min add compounds dissolved in DMSO. Mix well, but do not vortex see Note 4). 

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