1,4-Benzenedisulfonic acid, 2-[[4-chloro-6-[[4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]amino]-1,3,5-triazin-2 -yl]amino]-5-[[4,5-dihydro-3-methyl-5-oxo-1-[4-[[2-(sulfooxy)ethyl]sulfonyl ]phenyl]-1H-pyr