however , by adding 0.5-5 mm cobalt ( ii ) sulphate heptahydrate , nickel ( ii ) sulphate hexahydrate , zinc ( ii ) sulphate heptahydrate or cobalt ( ii ) diammonium sulphate hexahydrate to 0.5-1.5 mm copper ( ii ) sulphate pentahydrate , higher sensitivity and a quantitative response were attained .
C0056301
sulphate
C0038720
sulphate