It appears to match the structural signature of a legacy Lear 35 built in the early 80s. They retail from $500k to $1.2MM, and might make a good tool for spraying extremely isolated trails.
In the midst of this seasons (2013-14) massacre of storms and human health, we noticed a decidedly different super thin trail being sprayed only moments long before this private aircraft shut off its sprayer and flew out of sight. It drew a several mile long white trail in the sky that continued to wisp into the common white powder clouds that are choking our world.
Keep your cameras pointed up for changes in their techniques. It looks like the folks that are spraying these trails are willing to use outdated private aircraft to further confuse the lost.