ASTM: D1068A: Iron by Atomic Absorption, Direct
|
Official Method Name
|
Standard Test Methods for Iron in Water |
|---|---|
|
Current Revision
| 1996 |
|
Media
|
WATER |
|
Instrumentation
|
Flame Atomic Absorption |
|
Method Subcategory
|
Inorganic |
|
Method Source
|
|
|
Citation
|
|
|
Brief Method Summary
|
Iron is determined by atomic absorption spectrophotometry. Dissolved iron is determined by atomizing the filtered sample directly with no pretreatment. Total recoverable iron is determined by atomizing the sample following hydrochloric-nitric acid digestion and filtration. |
|
Scope and Application
|
These test methods cover the determination of iron in water. Procedures are given for determining total iron, dissolved iron, and ferrous iron. Undissolved iron may be calculated from the total iron and dissolved iron determinations. |
|
Applicable Concentration Range
|
0.1 - 5.0 mg/L |
|
Interferences
|
Sodium, potassium, barium, chloride and sulfate (5000 mg/L each), calcium, magnesium, chromium, manganese, cobalt, nickel, copper, zinc, palladium, silver, cadmium, tin, lead, lithium, mercury, selenium, aluminum, antimony, arsenic, vanadium, boron, and molybdenum (100 mg/L) do not interfere. Background correction (or chelation-extraction) may be necessary to determine low levels of iron in some waters. |
|
Quality Control Requirements
|
|
|
Sample Handling
|
Collect the sample in accordance with Practice D 1066, Specification D 1192, or Practices D 3370, as applicable. Samples should be preserved with HNO3 or HCl (sp gr 1.42) to a pH of 2 or less immediately at the time of collection. If only dissolved iron is to be determined, the sample shall be filtered through a 0.45-um membrane filter before acidification. |
|
Maximum Holding Time
|
The holding time for samples can be calculated in accordance with Practice D 4841. If ferrous iron is to be determined, the sample should be analyzed as soon as possible after collection and contact with atmospheric oxygen should be minimized. |
|
Relative Cost
|
Unknown |
|
Sample Preparation Methods
|
