[Bernard Marx]

Maybe there are fields of science other than analytical chemistry where such (incorrect) usage is the norm, but to us analytical chemists, "datum" is singular, and "data" is plural

Yes, I always think of the old Star Trek character Data who properly should have been named Datum. It seems that only some fields of science still use proper English. The system is breaking down. To be consistent, remember that medium is singular, media is plural; gymnasium is singular, gymnasia is plural, and so on. There are lots of other examples. The situation leads to the invention of new plural forms of words that are already plural. As another science-fiction character, a Vulcan, would have said: "It is not logical."

[Wonder Warthog]

"Yes, I always think of the old Star Trek character Data who properly should have been named Datum."

LOL--good point!

"As another science-fiction character, a Vulcan, would have said: "It is not logical.""

Or as another robot put it "This does not compute!".