MELISSA N. DUNKLE, PHD, is currently an Associate Research Scientist at Dow Benelux in The Netherlands. She focuses on R&D projects to advance analytical capabilities and improve the evaluation of natural gas feedstocks. WILLIAM L. WINNIFORD, PHD, is currently a Fellow at The Dow Chemical Company in Freeport, Texas. His primary field of research is analytical separations, currently focused on comprehensive two-dimensional chromatography.