1,8-Naphthalic anhydride-4-sulfonic acid, potassium salt 1H,3H-Naphtho(1,8-cd)pyran-6-sulfonic acid, 1,3-dioxo-, potassium salt 71501-16-1 EINECS 275-547-3 Potassium 1,3-dioxo-1H,3H-naphtho(1,8-cd)pyran-6-sulphonate