Set of 10 calibration standards, 500mg each, for organic SEC. Less branched polystyrene with anionic polymerization. Soluble in tetrahydrofuran (THF), chloroform, toluene, and o-dichlorobenzene (ODCB). The 10 MW included are: 580; 1,140; 1,300; 1,890; 2,790; 4,910; 6,660; 9,820; 13,000; 18,000. NOTE: Actual molecular weights may vary slightly depending on production lots. Refer to the COA for exact weights for the specific lot.