•A sampler for portable capillary electrophoresis to detect GHB in situ.•Sampler based on peristaltic pumps, a check valve, and a pinch valve.•LOD with CCD for GHB 1.7 mg L−1, meets the cutoff testing value for GHB in saliva. A compact, inexpensive sampler instrument for portable capillary electrophoresis was developed for monitoring illegal drugs in human body fluids and evaluated for γ-hydroxybutyric acid (GHB) in simulated saliva samples. The sampler uses peristaltic pumps and pinch and check valves to activate liquid flows. This short communication addresses aspects of CE associated with portability, open access instrumentation, and prospects of CE for citizen science. The extensive use of items provided by the electronic and computer industry contributes to this trend.