LaMotte SMART Spectro Spectrophotometer - Manual (Page 154)

IRON
I,I0-PHENANTHROLINE METHOD • CODE 3668-SC
QUANTITY CONTENTS CODE
15 mL * Acid Phenanthroline Indicator *2776-E
5 g * Iron Reducing Reagent *2777-C
1 Spoon, 0.1 g, plastic 0699
*WARNING: Reagents marked with a * are considered to be potential health hazards. To view
or print a Material Safety Data Sheet (MSDS) for these reagents see MSDS CD or
www.lamotte.com. To obtain a printed copy, contact LaMotte by e-mail, phone or fax.
Most natural waters contain some iron. Its presence may vary from small traces
to very large amounts in water which is contaminated by acid mine wastes. For
domestic use, the concentration should not exceed 0.2 ppm and for some
industrial applications not even a trace of iron can be tolerated. There are
many means available for removing or reducing the iron content. Water
softening resins are effective for removing small amounts of iron and special
ion exchange materials are selective for iron removal. High concentrations of
iron can be removed by such chemical processes as oxidation and lime or
lime-soda softening. Because of the many means of removing or reducing the
amount of iron in water, the particular method employed will depend largely
on the form of iron which is present and the end use of the treated water.
APPLICATION: Drinking, surface, and saline waters; domestic and industrial
wastes.
RANGE: 0.00–4.50 ppm Iron
METHOD: Ferric iron is reduced to ferrous iron and subsequently forms
a colored complex with phenanthroline for a quantitative
measure of total iron.
SAMPLE
HANDLING &
PRESERVATION The sample container should be cleaned with acid and rinsed
with deionized water. Addition of acid to adjust the sample
to pH 2–3 will prevent deposition of iron on the container
walls. Samples should be analyzed as soon as possible after
collection since ferrous iron undergoes oxidation to ferric
iron.
INTERFERENCES: Strong oxidizing agents, cyanide, nitrite, and phosphates,
chromium, zinc in concentrations exceeding 10 times that of
iron; cobalt and copper in excess of 5 mg/L, and nickel in
excess of 2 mg/L. Bismuth, cadmium, mercury, , and silver
precipitate phenanthroline.
SMART SPECTRO TEST PROCEDURES 01.07 Iron–I,I0-Phenanthroline Method 1/2