Maintain Anonymity in Responses While Tracking Respondent Participation?

I'm trying to find a way to ensure survey responses are anonymous while also tracking whether a particular recipient participated in the survey. For example, if I have a survey I want to send to 15 people, and I want each person to participate once and only once. In addition, I want complete anonymity of their answers.

Is there a way to see a list of which of the 15 people participated (perhaps at the end of a particular window of time) without being able to tie that data back to the actual answers (through timestamps or other means)? Would Individual/Personalized Links work here, or would those allow me to tie the email and name data back to the survey responses?