Sum of volatile matter at 135 °C (275 °F) and chlorides and sulfates (calculated as sodium salts), not more than 15 percent.
Matter insoluble in both water and chloroform, not more than 0.2 percent.
Total sulfonated quinaldines, sodium salts, not more than 0.2 percent.
Total sulfonated phthalic acids, sodium salts, not more than 0.2 percent.
2-(2-Quinolinyl)-1H-indene-1,3 (2H)-dione, not more than 4 parts per million.
Sum of sodium salts of the monosulfonates of 2-(2-quinolinyl)-1H-indene-1,3 (2H)-dione, not less than 75 percent.
Sum of sodium salts of the disulfonates of 2-(2-quinolinyl)-1H-indene-1,3 (2H)-dione, not more than 15 percent.
2-(2,3-Dihydro-1,3-dioxo-1H-indene-2-yl)-6, 8-quinolinedisulfonic acid, disodium salt, not more than 3 percent.
Diethyl ether soluble matter other than that specified, not more than 2 parts per million, using added 2-(2-quinolinyl)-1H-indene-1,3 (2H)-dione for calibration.
Lead (as Pb), not more than 20 parts per million.
Arsenic (as As), not more than 3 parts per million.
Mercury (as Hg), not more than 1 part per million.
Total color, not less than 85 percent.
21 C.F.R. §74.1710