EPA-NERL: 245.2: Mercury by CVAA (Automated)
|
Official Method Name
|
Mercury (Automated Cold Vapor Technique) |
|---|---|
|
Current Revision
| Issued 1974 |
|
Media
|
WATER |
|
Instrumentation
|
Cold Vapor Atomic Absorption |
|
Method Subcategory
|
Inorganic |
|
Method Source
|
|
|
Citation
|
|
|
Brief Method Summary
|
Inorganic mercury in a sample is reduced to the elemental state (using SnSO4 or SnCl2) and aerated from solution. The mercury vapor passes through a cell positioned in the light path of a cold vapor atomic absorption (CVAA) spectrophotometer. The concentration of mercury is measured using the CVAA spectrophotometer. To detect total mercury (inorganic and organic mercury), the sample is treated with potassium permanganate and potassium persulfate to oxidize organic mercury compounds. After oxidation, the samples are analyzed as inorganic mercury. |
|
Scope and Application
|
This method determines mercury in surface waters and in certain saline waters, wastewaters, effluents, and domestic sewages. Inorganic mercury or total mercury can be determined. |
|
Applicable Concentration Range
|
0.2 -20.0 ug/L |
|
Interferences
|
(A) Ions and metals: Sulfide, chloride, copper, and tellurium are reported interferences. (B) Volatile organic materials: Certain volatile organic compounds which absorb in the range of mercury are reported interferences. A preliminary run under oxidizing conditions, without stannous sulfate, would determine if certain volatile organic materials are present. (C) Interferences: All interferences can be overcome by use of the Manual Mercury Method. (D) Contamination: Avoid contact with materials that may contain mercury (e.g., glassware that was in contact with a mercury reagent). |
|
Quality Control Requirements
|
Not Provided |
|
Sample Handling
|
Preserve samples to pH < 2 with nitric acid upon collection. If dissolved mercury is desired, filter the sample. |
|
Maximum Holding Time
|
Not Provided |
|
Relative Cost
|
$51 to $200 |
|
Sample Preparation Methods
|
