grade ACS reagent, reag. ISO,  reag. Ph. Eur.  puriss. p.a.  assay ≥99.0%  form  crystalline  impurities ≤0.0005% heavy metals (as Pb)  ≤0.0005% total  nitrogen (N)  ≤0.01% in water insoluble  matters  ≤0.03% free alkali (as  NaOH)  ≤0.05% free acid (as  H$_{2}$SO$_{4}$)  loss ≤0.5% loss on ignition, August 2020 EN-c4f_annexiitechspeciiitechoffer_en.docx  EN-c4f_annexiitechspeciiitechoffer_en.docx Page 42 of 76 