Iron Test Kits
|Range||MDL||Method||Type||Kit Cat. No.||Refill|
|0.0 - 1.0 & 1 - 10 ppm||0.05 ppm||Phenanthroline (total & ferrous)||CHEMets||K-6210||R-6201|
|0 - 30 & 30 - 300 ppm||5 ppm||Phenanthroline (total & ferrous)||VACUettes||K-6210D||R-6201D|
|0.0 -1.0 & 1 - 10 ppm||0.05 ppm||Phenanthroline (total & soluble)||CHEMets||K-6010||R-6001|
|0 - 30 & 30 - 300 ppm||5 ppm||Phenanthroline (total & soluble)||VACUettes||K-6010D||R-6001D|
|0 - 60 & 60 - 600 ppm||10 ppm||Phenanthroline (total & soluble)||VACUettes||K-6010A||R-6001A|
|0 - 120 & 120 - 1,200 ppm||20 ppm||Phenanthroline (total & soluble)||VACUettes||K-6010B||R-6001B|
|0 - 1,200 & 1,200 - 12,000 ppm||200 ppm||Phenanthroline (total & soluble)||VACUettes||K-6010C||R-6001C|
|0 - 100 & 100 - 1,000 mg/l||5 mg/l||Ferric Thiocyanate (Iron in brine)||CHEMets||K-6002||R-6002|
|Range||Method||Type||Kit Cat. No.|
|0 - 2.50 ppm||PDTS (total)||Vacu-vials||K-6023|
|0 - 6.00 ppm||Phenanthroline (total & ferrous)||Vacu-vials||K-6203|
|0 - 6.00 ppm||Phenanthroline (total & soluble)||Vacu-vials||K-6003|
The CHEMetrics test kits for the determination of Iron in aqueous solutions are based on patented Self-Filling Reagent Ampoule technology, and employ the phenanthroline, PDTS and ferric thiocyanate methods, delivering sensitivity and accuracy within two minutes or less. Premixed. Premeasured. Precise. Each kit contains 30 tests. Suitable for potable and surface water as well as oil field brine testing.
The Phenanthroline Method (total & soluble; total & ferrous)
With the Phenanthroline method, ferrous iron reacts with 1,10-phenanthroline to form an orange-coloured chelate. To determine total iron, thioglycolic acid solution is added to reduce ferric iron to the ferrous state. The reagent formulation minimises interferences from various metals. Results are expressed as ppm (mg/l) Fe.
APHA Standard Methods, 22nd Ed., Method 3500-Fe B - 1997.
ASTM D 1068-77, Iron in Water, Test Method A.
J.A. Tetlow and A.L. Wilson, "The Absorptiometric Determination of Iron in Boiler Feed-water," Analyst. Vol. 89, p. 442 (1964).
The PDTS Method (total)
CHEMetrics' colourimetric method for determining total iron uses thioglycolic acid to dissolve particulate iron and to reduce iron from the ferric to the ferrous state. Ferrous iron then reacts with PDTS (3-(2-pyridyl)-5,6- bis(4-phenylsulfonic acid)-1,2,4-triazine disodium salt) in acid solution to form a purple-coloured chelate. Results are expressed as ppm (mg/l) Fe.
G. Frederick Smith Chemical Co., The Iron Reagents, 3rd ed., p. 47 (1980).
J. A. Tetlow and A. L. Wilson, "The Absorptiometric Determination of Iron in Boiler Feed-water," Analyst. Vol. 89, p. 442 (1964).
The Ferric Thiocyanate Method (Iron in Brine)
The Iron in Brine test employs the ferric thiocyanate chemistry. In an acidic solution, hydrogen peroxide oxidises ferrous iron. The resulting ferric iron reacts with ammonium thiocyanate forming a red-orange colored thiocyanate complex, in direct proportion to the iron concentration.
Results, expressed in mg/l, can be converted to mg/kg by dividing by the density of the brine.
D. F. Boltz and J. A. Howell, eds., Colorimetric Determination of Nonmetals, 2nd ed., Vol. 8, p. 304 (1978).
Carpenter, J.F. "A New Field Method for Determining the Levels of Iron Contamination in Oilfield Completion Brine", SPE International Symposium (2004).
Iron is present in nature in the form of its oxides, or in combination with silicon or sulphur. High concentrations in surface waters can indicate the presence of industrial effluents or runoff. The soluble iron content of surface waters rarely exceeds 1 mg/l, while ground waters often contain higher concentrations. Elevated levels in drinking water supplies are most commonly the result of corrosion of old cast iron water pipes.
The drinking water standards for iron are generally set more for aesthetic reasons and taste than health concerns. Higher iron concentrations can result in discoloured water with an undesirable brown or orange colour. The US National Secondary Drinking Water Standard for iron is 0.3 mg/l, as iron concentrations in excess of this level impart a foul taste and cause staining. The Prescribed Concentration or Value (PCV) for Iron in drinking water supplies in the UK is 200µg/l or ppb (0.2 mg/l). The Indicator Parametric Value for Iron in drinking water in Ireland is the same.
Iron contamination in oil field brines are typically a result of corrosion processes of iron-containing metallic components and equipment. Accumulation of insoluble iron salts in a brine completion fluid can result in substantial formation damage and can significantly affect the productivity of an oil well. Quantifying total iron in brine is critical.