Phenol and gallic acid are a solid substance. If you need to prepare a 1000 ppm stock solution of phenol 10000ppm = 10000 mg/L= 100mg/100ml =0.1gm/100ml
weight 0.1 gm of phenol crustal and put it in volumetric flask. add 10 ml ( d.w. desolive it and complete the volume to 100 ml with d.w.
In case the phenol purity is 80% i.e you must multiple the weight by reverse of 80% . you will weight 0.1*100/80=0.125 gm