Certified GKH Gardening Expert
Purslane is quite juicy and can be difficult to dry without a dehydrator. You could experiment with drying it in the oven on 6-8 hours on the lowest setting (but do not leave it unattended!). Then check whether they are fully dried, and if not, put them in for a few hours more.
This article has more information. You may want to follow the instructions for drying juicy fruit: