In WA state, if I accept separation pay, am I still entitled to collect Unemployment benefits?

My position was recently eliminated. I'm eligible for unemployment benefits. My former employee is asking I sign an "Election to Participate and Release of all Claims" form in order for me to receive separation pay. If I accept the separation pay, am I still entitled to collect unemployment benefits? I'm afraid that if I sign the form, I release my right to Unemployment benefits. Can they do that?