The method is improved for measuring formaldehyde in air by the method of pararosaniline hydrochloride using toxic mercury reagent.
盐酸副玫瑰苯胺法测定空气中甲醛，使用了有毒的汞试剂，为此对该法进行了改进。
2
The solution in ampoules has been measured by formaldehyde absorbing-pararosaniline spectrophotometric method without significant difference between preparing value and measuring value.
配制完成后使用甲醛吸收-副玫瑰苯胺分光光度法对其进行了多次重复测量，结果表明，测量值与配制值一致。
3
To study the determination of sulfite in food by pararosaniline hydrochloric spectrophotometry, then according to the sample characteristic, the treatment select soak, ultrasonic and distill.