Recent developments in life sciences technology, such as electrochemical biosensing, harness the unique properties of metallic nanocrystals. The localized surface plasmon resonance (LSPR) scattering spectra of gold nanocrystals are effective electrochemical sensors of both biological and organic molecules; however, the LSPR is directly related to the size and shape of the gold nanocrystals and the local environment. Changes in these parameters drastically affect gold nanocrystal functionality. Hyperspectral dark-field analysis and correlated scanning electron microscopy demonstrate that the ionic composition of complex electrolyte solutions containing predominantly chloride anions significantly influences the morphological stability of gold nanorods (AuNRs). The introduction of small concentrations of oxoanions with increasing numbers of hydroxyl groups drastically alters the dissolution onset potential and the dissolution pathway of single AuNRs. At high concentrations of chloride ions, both bicarbonate and phosphate ions prevent dissolution until applying highly anodic potentials. Applying an anodic bias to single anion chloride environments causes a drastic average red-shift. As the number of hydroxyl groups of the competing oxoanion increases, the magnitude of the shift decreases and then begins to blue-shift. Understanding the impact of complex anion solutions on the stability of metal nanocrystal modified electrodes improves capabilities of electrochemical biosensing by increasing the potential window for sensing of new species.