Question
I have area that I need to make sure nothing can grow where I can pine straw the area. Aprox size of area is 10ft by 100ft

Answer
Pine straw mulch by itself will kill weeds. If you want to make doubly sure, then you might consider spraying a nonselective weedkiller on the existing weeds before putting down the pine straw. Alternatively, you can cover the area with cardboard or newspaper beforehand; this will smother the existing. In time either material will breakdown. Be prepared that wind, birds, squirrels etc. will introduce seeds into the area. These will sprout and the 'medium' of decomposing pine straw and other materials might selectively favor the germination and growth of a particular plant species.