Quickly screen solvents for organic solids

In this article, we will review a number of methods used to estimate the solubility in a wide variety of solvents. These methods can help in putting together a list of candidate solvents to test in the laboratory. To illustrate the utility and limitations of these methods, we will discuss how to use them to identify candidate solvents for crystallization processes. The methods we will review are: (1) Robbins chart, a qualitative guide to identifying general classes of solvents; (2) UNIFAC, a group contribution method for estimating an activity coefficient and, from this, assessing solubility; (3) radius of interaction analysis utilizing Hansen solubility parameters; and (4) use of Hansen solubility parameters to estimate an activity coefficient and solubility.