Ralph

If you prefer a low pH level HCA try this

EDTA4Na 12g or DTPA pentasodium salt (solution) 25ml
Sodium sulfite 200g
Sodium bisulfite 6g
Sodium citrate 4g

to make 1000ml stock solution
dilute 1+9 for working solution

Wolfgang Moersch
www.moersch-photochemie.de