Could you at least take the time to define "trivial both in content and in testing"? I have a feeling that if you were to take the time you might find that 20 Mule Team Borax would pass the tests. There is no specific requirement for Chloride or Sulfate. I found it surprising that passing the carbonate test means that carbonate is less than about 1%.
Originally Posted by Photo Engineer
The foreword states that "This is one of a series of standards that establishes criteria of purity for chemicals used in processing photographic materials."
I'm of the opinion that what you are really saying is "Don't confuse me with the facts. My mind's made up."
I'm not saying you should use any particular brand or grade of anything. The cheap stuff does pass the test for iron. Whether its content of chloride and sulfate would cause it to fail the ammoniacal silver test, I do not know. Perhaps you could inform us on the basis of known specs in what ways the best is better than the technical powder for processing film.