Screening volatile acids

One has to emphasize that MS also is associated with several drawbacks when it comes to bioactivity screening. First of all, the optimum, native conditions for bioactivity screening (pH 7.2, addition of 150 mM sodium chloride) are entirely incompatible with optimum conditions for MS detection which, for ESI-MS, typically require acidic pH values and the presence of organic modifiers to enhance ionization properties of the analytes. Assay development for MS-based assays therefore mainly requires the testing of different assay conditions, particularly the replacement of nonvolatile buffers with MS-compatible volatile buffers. Furthermore, it is essential to monitor ion suppression effects, for example, by the... 

Viability of Starch Derivatives as Flavoring Encapsulants. The capillary GC vapor phase flux term (defined by a percent external standard or ZEStD flux) previously described (34) was used to screen starch derivatives (oxidized, dextrinized and/or covalent amino acid linkage) as to their flavor encapsulation potential. The samples were prepared as previously described (34) with the exception of an added reduced pressure deaeration step, thus allowing the use of the headspace diffusivity versus retention standard curves to predict volatile lemon oil retention following spray drying. 

An interesting sidelight of the monensin story is the discovery of its further use as a growth promotant in ruminants. For years, synthetic chemicals had been screened for activity in cattle and sheep diets to eliminate the wasteful methane production and to increase volatile fatty acid formation (especially propionate) in the rumen, wiiich would improve feed efficiency. Although the concept was sound, no useful products resulted. Experimentation with monensin showed that polyethers have this activity and these compounds are used widely today for this purpose. ... 

Sedative properties have been documented for valerian and have been attributed to both the volatile oil and the valepotriate fraction. Screening of the volatile oil components for sedative activity concluded that valerenal and valerenic acid were the most active compounds. 

---