[quote="chem geek":hor6s0ek]
Bloomfield said:
It's short for the name of the chemical dye. The names are as follows:
OTO -
Ortho
tolidine - in R-0600 Taylor reagent indicator dye
DPD - N,N-
diethyl-p-
phenylene
diamine - R-0003 Taylor indicator dye
FAS -
Ferrous
Ammonium
Sulfate - R-0871 Taylor titrating reagent