A question for chemists and those who create developers:
Why did Ryuji Suzuki and others use Salicylic acid and TEA to chelate iron, when DTPA will work?

Here's some interesting info about DTPA: www.dow.com/scripts/litorder.asp?filepath=/113-01343.pdf
Notice that Fe (iron) is included in the list of metals chelated. Iron is the curse of ascorbate developers because it eventually destroys all ascorbate via the Fenton reaction. Hence the motive to chelate iron. DTPA is used in XTOL (1 g/L, according to the patent), so I'm wondering why others don't use it.

Mark Overton