The microextraction sampling technique was integrated with triple quadrupoleinductively coupled plasma–mass spectrometry (TQ–ICP–MS) to directly sample and measure the isotopic compositions of uranium (U) and plutonium (Pu) from cotton swipes. Once extracted, the U/Pu were directed into the TQ–ICP–MS instrument for isotopic determination. Carbon dioxide (CO2) and helium (He) gases were delivered to a collision reaction cell within the ICP–MS system for ion separation. The CO2 reacts with the U+ forming UO+ which is ultimately separated from the Pu+ ions of interest in the third quadrupole. This study demonstrates direct liquid extraction of U/Pu from a solid surface and subsequent measurement by TQ–ICP–MS in <60 s. Flow rates were optimized (0.3 mL min–1 CO2 and 5 mL min–1 He) in the reaction cell of the ICP–MS system to maximize the Pu signal while minimizing U interferences (i.e., 238U+ tail and 238UH+) at m/z 239. Low levels of Pu (∼2 pg) were deposited on a cotton swipe along with U at concentrations ranging from 20 to 200 ng. The 240Pu/239Pu ratio was measured with <7% relative difference from the certified value at all U concentrations. Major and minor U isotope ratios were also measured with <4% relative difference. This highlights that the microextraction–TQ–ICP–MS method can extract a mixed U/Pu sample directly from a cotton swipe and measure both isotopic systems without chemical separation.