One of Robinsons primary research interests is environmental chemistry, including the detection of trace elements in environmental matrices by nuclear methods.  In 1991, while at ORNL, Robinson was a participant in a well-publicized investigation into the cause of the death of 19th-century U.S. President Zachary Taylor. When Taylor died rather suddenly in 1850, the cause of his death was listed as gastroenteritis, but some historians thought he might have been poisoned with arsenic. His descendants gave permission for his remains to be exhumed in order to allow analysis of tiny samples of his hair and fingernails. With ORNLs High Flux Isotope Reactor as a neutron source, Robinson and colleagues used neutron activation analysis to measure arsenic levels in the samples.
 The analysis led to a finding that Taylor did not die from arsenic poisoning, as arsenic was not detected in the samples, indicating that arsenic concentrations were many times lower than would be expected in arsenic poisoning.