The complexity of organic composition and temporal variability of atmospheric aerosols presents an extreme analytical challenge. Comprehensive two-dimensional gas chromatography (GC x GC) has been used on time integrated filter samples to reveal the presence of thousands of individual organic compounds in aerosols, but without defining the temporal variability in composition ideal for providing information on source resolution and human exposure to specific pollutants. We hereby introduce a new instrument, 2D-TAG, which combines our in-situ thermal desorption aerosol GC (TAG) instrument with GC x GC allowing for dramatically improved separation of organics with automated measurements at hourly timescales.