Tender For corrigendum : supply of chemical items - sulphuric acid ar , methylethyl ketone ar/gr , buffer titrisol ph-9 , buffer titrisol ph-7 , buffer titrisol ph-4 , ethyl alcohal , potassium chloride extra pure ar/gr , methanol gr , benzene pure ar/gr , lithium chloride ar/gr , iso-propanol gr , hydranal water standard , hydranal coulomat ag