By using sulpho acid to dissociate samples, using spectrophotometric method to determine micro-chrome in drainage sedimentary is very easy and simple with low cost.

采用王水分,分光光度法测定水系沉积物中微量铬,法简便,易作,成本低。

Recent method of synthesizing 3,5-xylenol is sulpho alkaline fusion of dimethylbenzene,it is a very complicated procedure with serious pollution and low-pure products.

国内目前生产工艺是间二甲苯的磺化碱熔法,法工艺过程复杂、污染严重,并且产纯度不高。