This is the recipe for home-made ORS.
The ORS recipe recommended by WHO and UNICEF (also known as reduced-osmolarity ORS) is:
#bb("Compound"color(white)(mmml)"g/L"color(white)(m)"mmol/L"color(white)(m)"mOsmol/L")#
#"NaCl"color(white)(mmmmmmmll)2.6color(white)(mmll)44.5color(white)(mmmmm)89#
#"Glucose"color(white)(mmmmmm)13.5color(white)(mmll)75color(white)(mmmmmll)75#
#"KCl"color(white)(mmmmmmmml)1.5color(white)(mmll)20color(white)(mmmmmll)40#
#"Na"_3"C"_6"H"_5"O"_7·2"H"_2"O"color(white)(m)2.9color(white)(mmll)10color(white)(mmmmmll)40#
#color(white)(mmmmmmmmmml)"Total Osmolarity ="color(white)(m)244#
#"Na"_3"C"_6"H"_5"O"_7·2"H"_2"O"# is sodium citrate dihydrate.
The normal osmolarity of blood is about 300 mOsmol/L.