abstract |
The present invention relates to a method for removing contaminants on a surface which is brought into contact with a surface of an aqueous solution of guanidine of formula (I): Wherein from, R 1, R 2, R 3 and R 4 may be the same or different, R 1, R 2, R 3 and R 4 each represent a hydrogen or hydrocarbyl bilim. |