Neonicotinoid pesticides have recently come under fire for their negative impacts on pollinators. However, seed treatments of neonicotinoid compounds such as imidacloprid are regularly applied to over 79% of maize grown commercially in the US. Thiamethoxam is one of the least studied of these compounds. In this study, I examined the variation of systemic uptake of thiamethoxam by maize seedlings using a liquid chromatography - mass spectrometry (LC-MS) protocol to observe thiamethoxam concentration in the 26 founder inbred lines of the Nested Association Mapping (NAM) panel, along with the inbreds Mo17 and W22. I observed that the mean differences in concentration 16 days post planting between tropical and temperate lines are significantly different. Additionally, I calculated a minimum value for percent thiamethoxam uptake from seed treatment for 8 inbred genotypes.