... sample 4.Basic chemical raw material 1. high quality of industrial naphthalene,technical naphthalene,Crude naphthalene ... grade), ≤ 0.06 (first level),≤ 0.08 (qualified level)ash:≤ 0.01(excellent grade),≤0 ... detectable at concentrations as low as 0.08 ppm by mass.[1] As an aromatic ... ada#bailichem.cn 0086-15081709808skype:hbadachem high quality of industrial naphthalene,technical naphthalene,crude naphthnalene ...