Sterilization - (May/20/2014 )

How do I know the steilization method of a chemical, but its details is  not known?

Due to the ambiguity of english I'm not sure if you are asking how a chemical can sterilize something (e.g. peroxide used to fumigate) or if you are asking how to sterilize the chemical itself.

In both cases, the answer lies in the chemistry of the chemical.  For instance, a lot of chemicals can be sterilized by autoclaving, but this won't work for alcohols as they will evaporate, and some compounds will decay (e.g. DEPC).  In this cases, filter sterilization may be more appropriate, but you need to ensure that the filter won't get dissolved by the chemical you are trying to filter.

The method of action of sterilization by a chemical is dependent on the chemistry - some dissolve membranes and precipitate proteins (e.g. alcohols and chloroform), some oxidise (peroxide etc.) some cross link proteins (formaldehyde), some do more than one mode of action and some do things that I don't know about (e.g. trigene - it's a mixture I know, so probably multiple actions).

How about potassium phosphate dibasic, calcium chloride and choline dihydrogen citrate? Are they all sterilized by filter? Why?

Potassium phosphate and Calcium chloride can both be autoclaved.  No idea about choline.  If in doubt, filter sterilize.  I doubt choline will dissolve any of the common filters.