Chip-scale gas chromatography: From injection through detection

A chip-sized gas chromatograph can detect hazardous volatile organic compounds in seconds. To avoid thermal crosstalk, the three main components of a microscale gas chromatograph—injector, separation column and mass detector—are normally placed on separate chips. Dr. Masoud Agah and co-workers from Virginia Polytechnic Institute and State University, United States, have combined these components onto a single chip using an innovative setup. The team fabricated a microfluidic injector and alumina-based column in close proximity to reduce analysis time. As samples elute from the column, they are photoionized by a helium-based detector that spots picograms of organic molecules without relying on thermal pre-concentration. The integrated device detects contaminants such as chlorobenzene and xylene with an extremely sharp chromatographic peak—indicating that thermal effects are minimized—and at speeds that allow real-time monitoring of liquids and air.