certified reference material, TraceCERT ® , 2000 μg/mL each component in methylene chloride: benzene (1:1) Components: Acenaphthene; Acenaphthylene; Anthracene; Benz[ a ]anthracene; Benzo[ b ]fluoranthene; Benzo[ k ]fluoranthene; Benzo[ ghi ]perylene; Benzo(a)pyrene; Chrysene;…