NEMI Method Summary


Method Summary Information

Method Number:

I-7800

Media:

WATER

Revision:

1972

Method Source:

U.S. Geological Survey (USGS)

Subcategory:

INORGANIC

Analytes in this method

Official Name:

Strontium, atomic absorption spectrometric, direct

Descriptive Name

Strontium, suspended recoverable, atomic absorption spectrometric

Source Info:

USGS Branch of Information Services
Box 25286, MS 417
Federal Center
Denver, CO 80225-0286
Phone: 303-202-4700

Citation:

USGS Methods, Volume A1

250967

Byte file

Brief Method
Summary:

Strontium is determined by atomic absorption spectrometry. Lanthanum chloride and excess potassium chloride are added to mask interferences and control ionization of strontium in the flame (Fishman and Downs, 1966). This procedure may be automated by the addition of a sampler, a proportioning pump, and a strip-chart recorder or a printer or both (fig. 1).

Scope And
Application:

This method may be used to analyze water, brines, and water-suspended sediment containing from 10 to 5,000 ug/L of strontium. Samples containing more than 5,000 ug/L need to be diluted.
Suspended recoverable strontium is calculated by subtracting dissolved strontium from total recoverable strontium.
Total recoverable strontium in water-suspended sediment needs to undergo preliminary digestion-solubilization by method I-3485.
Samples containing more than 2,500 mg/L of total solutes need first to be diluted. If the strontium concentration in the diluted sample is below detection, the undiluted sample needs to be analyzed by the standard-addition method.

Applicable
Conc Range:

Interferences:

Sodium and potassium decrease the strontium ionization in the flame. To control the ionization, 1,000 mg/L of potassium are added to both standards and samples.
Aluminum, phosphate, and silica interfere but are masked by the addition of lanthanum.
Nitrate interferes, but in the presence of lanthanum chloride-potassium chloride solution at least 2,000 mg/L can be tolerated. The addition of nitric acid in the field to preserve samples causes no problem.
Low strontium values result even in the presence of potassium and lanthanum if the dissolved-solids concentration exceeds 2,500 mg/L. For this reason, brines and highly mineralized waters must either be diluted or analyzed by the standard-addition method. For the standard-addition method, the dissolved solids content of the samples must be reduced to less than 20,000 mg/L.

QC Requirements:

No QC requirements. Suspended recoverable strontium is a calculation.

Sample Handling:

Max Holding Time:

Relative Cost:

Less than $50

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Method Summary Information