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

络合指示剂是在碱性条件下、甲醛和亚氨二乙酸缩合。

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

用百里酚蓝-甲酚红、溴甲酚绿-甲红混和指示剂的测试效果较差。