Rosuvastatin Acid Standard

7-[4-(4-Fluorophenyl)-6-(1-methylethyl)-2-(methyl-methylsulfonyl-amino)-pyrimidin-5-yl]-3,5-dihydroxy-hept-6-enoic Acid;(3R,5S,6E)-7-[4-(4-Fluorophenyl)-2-(N-methylmethanesulfonamido)-6-(propan-2-yl)pyrimidin-5-yl]-3,5-dihydroxyhept-6-enoic Acid;