Is it possible to connect a Samson Mixpad 4 to a Canon GL2 camcorder?

Absolutely!
All you need is a stereo 1/8 (3.5mm) to 2 mono 1/4" plugs. You can also go from the 1/8 to 2 RCA plugs, but that limits your output options. You'll do best with the 1/4. Anyway, connect to your Mixpad outputs with the 1/4, and plug the 1/8 into the mic input on the camera, set your levels to line, and you're good to go. Set mic volumes on mixpad to the 0 point, use the trims to set levels on input for best results/lo/no noise results.

Thanks for the quick reply, Douglas. Do you have experience using the Mixpad? If so, could you tell me if it has any problems like output hiss, hum or distortion? How does it compare in sound quality to more expensive mixers like the Sound Devices Mixpre?

It's not a Sound Devices, that's for sure. Any mixer though, can have hum, hiss, distortion. It's all in the use of the mixer. I mix every single day on one of my systems using a Mixpad6. It's a very good little unit, and more than capable for most things. I just used one this week on a shoot for the Ohana Hotel chain here in Hawaii. With the battery power (it does eat batteries if you use phantom) and shoulder strap, it has been great. I wish I had a sound devices, then again, I need to feed 3 cams from one box, so this works great.
I did modify mine so it's got small "ears" that prevent the knobs from being broken off if it brushes something sideways.