Alizarin complexone is obtained by the condensation of alizarin with formaldehyde solution and iminodiacetic acid in the presence of alkaline conditions.

茜素络合指示剂是在碱性条件茜素、甲醛和亚氨二乙酸缩合而成。

So the mixed indicator of phenolphthalein with alizarin red-methyl red could be used as the new indicator for the alkalify water determination.

里酚蓝-甲酚红、溴甲酚绿-甲红混和指示剂的测试效果较差。