(HPS by Zeptometrix) Nitrate Anion IC Single-Component Standard from Sodium Nitrate at 1,000 ug/mL in H2O. Can be used as stock solution for nitrate as nitrate, EPA Method 9056. If you need to report Nitrogen using a nitrate source, please see IC-NO3-M, 1,000 g/mL Nitrogen in H2O instead.