elvisd - 7-5-2010 at 04:22
Would iron chloride work as a stock solution for a spectrophotometer analysis for iron in water?
JohnWW - 7-5-2010 at 05:10
Probably not, because it is too susceptible to hydrolysis, except in VERY acid solution (with an excess of HCl). Fe in water can be colorimetrically
or spectrophotometrically determined as an intensely-colored (usually red) complex, which stabilizes it in solution, most often as the
o-phenanthroline complex. The spectrophotometer is calibrated using a series of standard solutions of known concentration of Fe in solution as the
complex.
Ozone - 7-5-2010 at 07:59
EM sells Fe standard for ICP as 1000 ug/mL FeCl3 in dilute HCl. Note that only Fe2+ forms the tris-o-phenanthroline complex. This is why hydroxylamine
or some other reductor is usually applied to reduce the total iron to 2+. The difference between the absorbance at 510nm with and without
hydroxylamine is the Fe3+. The calibration range for this assay is between 1-5 ug/mL total Fe.
Cheers,
O3