Microfluidic chip capable of synthesizing radioactively labeled molecules on a scale suitable for human imaging with positron emission tomography

Described herein are automated, integrated microfluidic device comprising a chemical reaction chip comprising for performing chemical reaction, a microscale column integrated with the chip and configured for liquid flow from the column to at least one flow channel, and wherein the fluid flow into the column is controlled by on-chip valves; and comprising at least two on-chip valves for controlling fluid flow in the microfluidic device.