Benzoic acid, 2-[[4-chloro-6-[[3-[[8-[[4-chloro-6-(methylphenylamino)-1,3,5-triazin-2-yl]amino]-1-hydroxy-3,6-disulfo-2-naphthalenyl]azo]-4-sulfophenyl]amino]-1,3,5-triazin-2-yl]amino]-5-sulfo-, tetrasodium salt