21. Bioassay-guided fractionation is a common method to find biologically active compounds. 22. Field flow fractionation is based on laminar flow of particles in a solution. 23. These isomers are thermally interconvertible but can be separated by low temperature fractionation . 24. Electrofiltration is regarded as an appropriate technique for concentration and fractionation of biopolymers. 25. This assumes that the conversion to graphite does not introduce significant additional fractionation . 26. Now the measured fraction modern can be determined, by correcting for fractionation . 27. This phenomenon is known as Natural Isotopic Fractionation ( see Figure 3 ). 28. Isotopic fractionation in the hydrologic cycle for more details] 29. Some of the magmas underwent fractionation after their formation, but not all. 30. Calcium isotope fractionation during mineral formation has led to several applications of calcium isotopes.
