Initial heating of the phenol and formaldehyde (in the presence of an acid or base to get the reaction going) produced a shellac-like liquid good for coating surfaces like a varnish.
开始加热，酚和甲醛(需有酸或碱促使其反应进行)便产生了像紫胶样的液体，能像清漆一样涂于物体表面。
2
The formaldehyde contents in tofu filtrate, liquid separated from beancurd and the distillate of beancurd were measured by acid-base titration.
制作过程中加入吊白块，用酸碱滴定法分别测定水豆腐压滤液、离浆液和蒸馏液中甲醛含量。
3
Set up the liquid chromatography method for determining hydrolyzed free formaldehyde in textiles.