EPA Method 7131-A

Summit Environmental Technologies prides itself in its expansive testing capabilities in a variety of different fields. To find out if Summit conducts this test, contact us at 330-253-8211 today.

PDF IconView Actual EPA Method 7131-A (PDF File)


EPA Method 7131-A:
Cadmium by GFAA. Official Name: Cadmium by Graphite Furnace Atomic Absorption

Summary:
Although methods have been reported for the analysis of solids by graphite furnace atomic absorption spectrophotometry, the technique generally is limited to metals in solution or solubilized through some form of sample processing. Preliminary treatment of wastes, both solid and aqueous, is always necessary because of the complexity and variability of sample matrix. Solids, slurries, and suspended material must be subjected to a solubilization process before analysis. This process may vary because of the metals to be determined and the nature of the sample being analyzed.Note: This method was integrated into General GFAA Method 7010 Jan-98.

Scope:
This method is used for the determination of cadmium in drinking water, surface water, saline waters, and domestic and industrial wastes. Drinking water free of particulates may be analyzed directly. Ground water, other aqueous samples, EP extracts, industrial wastes, soils, sludges, sediments, and other solid wastes require digestion by Methods 3005-3050 prior to analysis for both total and acid leachable metals. When analyzing for dissolved metals, acid digestion is not necessary for samples that have been filtered and preserved.

Citation:
SW-846 Online: Test Methods for Evaluating Solid Waste, Physical/Chemical Methods

Interferences:
(A) Cadmium analysis can suffer from severe nonspecific absorption and light scattering caused by matrix components during atomization. Simultaneous background correction is required to avoid erroneously high results.(B) Excess chloride may cause premature volatilization of cadmium. Ammonium phosphate used as a matrix modifier minimizes this loss.(C) Plastic pipet tips (yellow) contain cadmium. Use "cadmium-free" tips.(D) See Method 7010 if interferences are suspected.

QC Requirements:
(see SW-846 Method 7010 for general QC requirements)

Maximum Holding Time:
See SW-846 Chapter Three for information.

Media:
VARIOUS

Subcategory:
Inorganic

Concentration:
DL - * (* Upper detection limit is defined as the highest calibration point, as determined by analyst.)

Sample Prep:
See Method 7010

Precision:
-

Detection:
DL is the detection level specified in the method.

Revision Number:
Sep-94