Methods and devices for controlled evaporation of solvent from a solution are provided. In one embodiment, the device can control evaporation of different solutions comprising solvents of dissimilar volatilities simultaneously. In another embodiment, control over the flow of solvent vapor out of the device is provided by selecting the pressure at an inlet port and an exhaust port of the device. In yet another embodiment, control over the flow of solvent vapor out of the device is provided by selecting the size of a disk flow control orifice positioned between the wells and a vapor removal outlet of the device. In still another embodiment, control over the flow of solvent vapor out of the device is provided by the opening and closing of the vapor removal outlet of the device. In yet a further embodiment, the rate of evaporation of solvent is controlled by controlling the temperature of the solution. The flow rate control mechanisms can be used alone or in any combination to control evaporation of one or more solvents from solutions.