USGS Test Method I-2193-02


Method information displayed is provided for informational purposes only.
ALS - Columbia may or may not offer methods shown. Please contact us to learn about ALS - Columbia's latest available methods. No warranty (express or implied) is made as to the website accuracy, completeness, or applicability (such as the age of a method and whether or not it applies to your project).

Analytical testing dots

PDF IconView Actual USGS Method I-2193-02 (PDF File)


Source:
USGS

Method Name:
Laboratory arsenic speciation, nitric acid mobile phase, ICP-MS detection, dissolved. Official Name: Laboratory arsenic speciation, nitric acid mobile phase, ICP-MS detection, dissolved

Description:
This method includes modifications of a method described by Jackson and others (2000) for the separation and determination of arsenite (As(III)), arsenate (As(V)), monomethylarsonate (MMA), and dimethylarsinate (DMA) using high performance liquid chromatography with ICP-MS detection. Nitric acid is used as the mobile phase to chromatographically separate arsenic species making it possible to analyze acid mine drainage.

Scope:
This method is used to determine dissolved arsenite (As(III)), arsenate (As(V)), monomethylarsonate (MMA), and dimethylarsinate (DMA) in water including acid mine drainage. Addition of 2% (by volume) of methanol to the mobile phase also allows for the separation and determination of roxarsone.

Citation:
Garbarino, J.R., Bednar, A.J., and Burkhart, M.R., Methods of Analysis of the U.S. Geological Survey National Water Quality Laboratory -- Arsenic Speciation in Natural-Water Samples Using Laboratory and Field Methods, U.S. Geological Survey Water-Resources Investigations Report 02-4144, 47 p.

Interferences:
Chemical and spectral interferences can affect the accuracy of determining arsenic species unless appropriate procedures are followed. Iron and manganese oxyhydroxide precipitates provide sorption sites for dissolved arsenic species that might negatively biasing arsenic speciation results. This effect can be minimized by decreasing the pH to stabilize the cations or by complexation of the cations. Use of an EDTA preservative works best for a wide range of sample matrices.As(III) can be oxidized to As(V) by photolytically prodcued free radicals. Opaque polyethylene sample bottles are used to elminate this effect.Spectral interference from argon-chloride molecular ion at m/z 75 when using ICP-MS to determine arsenic has been documented and suitable correction methods have been established. However, chromatographic separation minimizes chloride interference.

QC Requirements:
Calibrate instrument using calibration standards (CAL); quality control samples (QCS); and laboratory blanks (LB) analyzed at a minimum of 1 for every 10 samples.

Maximum Holding Time:
90 days

Media:
WATER

Subcategory:
Inorganic

Concentration:
MDL to 100

Precision:
The bias and variability of the laboratory-speciation methods were established using reference materials, laboratory solutions having known arsenic species concentrations in reagent-water matrix, and test samples from ground-water, acid mine drainage, and surface-water sites.

Detection:
The MDL was determined using the methodology described in USEPA Report Part 136, Appendix B.

Revision Number:
2002

Analytical testing dots

Related Methods:
Test Method 500001    Test Method 500007    Test Method 500021    Test Method 500061    Test Method 500071    Test Method 500076    Test Method 500081    Test Method 500086    Test Method 500090    Test Method 500201   


<-- Search again



*Method information displayed is provided as a convenience only. No warranty (express or implied) is made as to its accuracy, completeness, or applicability (such as the age of a method and whether or not it applies to your project).

Suggestions? The test methods page continues to expand and improve. If you have suggestions for improvement, we would enjoy hearing from you. Please contact the webmaster here.


Analytical testing dots