Although I've never used it on flash memory and that application is not mentioned on its site you could experiment a bit with Bart's Stuff Test
. Just don't let it run excessively long because of the limited number of write cycles of flash memory.
Found this on a forum: "you can kill a ssd with about 36 hours of 4k random writes. at least that's what Intel says....so be careful in your testing."
I also found this utility: http://www.flashmemorytoolkit.com/
It has some kind of error scan function.
But if there's any doubt about its reliability you'd best buy a new card and keep this one in reserve or for some other non-critical use.
When in doubt..... Press the shutter.