NEMI Method Summary

Method Summary Information

Method Number: I-5800 Media: SOILS/SEDIMENT
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, recoverable-from-bottom-material, dry wt, 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 bottom material containing at least 1.0 ug/g of strontium. If the sample solution contains more than 5,000 ug/L of strontium, it must be diluted.
Recoverable strontium from bottom material needs to undergo preliminary digestion-solubilization by method I-5485 before being determined.
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:
 10 to 5000 ug/L
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: Calibrate instrument using calibration standards (CAL); quality control samples (QCS); and laboratory blanks (LB) analyzed at a minimum of 1 for every 10 samples.
Sample Handling: Container description: Bottom Material (stream bed sediment) 500 mL wide mouth propylene bottle; no treatment or preservation requirements.
Max Holding Time:
Sample Prep Met I-5485
Relative Cost: Less than $50
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