Method and apparatus for determining a quality or characteristic of connectors in electronic components is provided. Methods include applying a UV-responsive indicator solution active for Pd, Ni, or Cu to a connector on an electrical component; irradiating the connector with UV radiation; detecting a response to the UV radiation; and determining a quality of the connector based on the response to the UV radiation. Apparatus includes an enclosure; a support; a dispenser oriented toward the substrate support; a source of UV-responsive indicator solution active for Pd, Ni, or Cu ions fluidly coupled to the dispenser; a UV source coupled to the enclosure; and a radiation sensor positioned to detect light inside the enclosure.