ASTM D6071-96(2000)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D 6071–96 (Reapproved 2000)
Standard Test Method for
Low Level Sodium in High Purity Water by Graphite Furnace
Atomic Absorption Spectroscopy
This standard is issued under the fixed designation D 6071; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope Graphite Furnace Atomic Absorption Spectrophotometry
D 4453 Practice for Handling of Ultra-Pure Water Samples
1.1 This test method covers the determination of trace
sodium in high purity water. The method range of concentra-
3. Terminology
tion is 1 to 40 µg/L sodium. The analyst may extend the range
3.1 Definitions:
once its applicability has been ascertained.
3.1.1 For definitions of terms used in this test method, refer
NOTE 1—It is necessary to perform replicate analysis and take an
to Terminology D 1129.
average to accurately determine values at the lower end of the stated
range.
4. Summary of Test Method
1.2 This test method is a graphite furnace atomic absorption
4.1 Sodium is determined by atomic absorption utilizing a
spectrophotometric method for the determination of trace
graphite furnace for sample atomization.
sodium impurities in ultra high purity water.
4.2 Asamplevolumeofseveralmicrolitres,dependingupon
1.3 This test method has been used successfully with a high
theconcentrationoftheanalyte,isdepositedonagraphitetube
purity water matrix. It is the responsibility of the analyst to
housed within an electrical furnace, and the system is heated in
determine the suitability of the test method for other matrices.
an inert gas environment.The sample is evaporated to dryness,
1.4 This standard does not purport to address all of the
ashed (charred or pyrolyzed), and atomized.
safety concerns, if any, associated with its use. It is the
4.3 Ground-stateatomsareproducedduringtheatomization
responsibility of the user of this standard to establish appro-
stage of the temperature program. The ground-state atoms
priate safety and health practices and determine the applica-
absorb the energy at a specific wavelength produced from a
bility of regulatory limitations prior to use.
source as they are bombarded by the energy. The amount of
energy absorbed is proportional to the concentration of the
2. Referenced Documents
analyte in the sample.
2.1 ASTM Standards:
4.4 The absorption signal produced during atomization is
D 1066 Practice for Sampling Steam
recorded on a chart recorder or stored in microprocessor
D 1129 Terminology Relating to Water
memory and compared to those standards taken through the
D 1192 Specification for Equipment for Sampling Water
same process by means of an analytical curve.
and Steam in Closed Conduits
4.5 A general guide for graphite furnace applications is
D 1193 Specification for Reagent Water
given in Practice D 3919.
D 2777 Practice for Determination of Precision and Bias of
5. Significance and Use
Applicable Test Methods of Committee D19 on Water
D 3370 Practices for SamplingWater from Closed Conduits
5.1 Small quantities of sodium, 1 to 10 µg/L, can be
D 3919 Practice for Measuring Trace Elements in Water by
significantinhighpressureboilersystemsandinnuclearpower
systems. Steam condensate from such systems must have less
than 10 µg/L. In addition, condensate polishing system efflu-
This test method is under the jurisdiction of ASTM Committee D19 on Water
ents should have less than 1 µg/L. Graphite furnace atomic
and is the direct responsibility of Subcommittee D19.03 on Sampling of Water and
absorption spectroscopy (GFAAS) represents technique for
Water-Formed Deposits, Surveillance of Water, and Flow Measurement of Water.
determining low concentrations of sodium.
Current edition approved Dec. 10, 1996. Published March 1997.
RP2712 Sub Program—Grab Sample Method Validation Report Results,
6. Interferences
Electric Power Research Institute, Palo Alto, CA 1987.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.1 No known interferences from other constituents are
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
found in high purity waters.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 6071–96 (2000)
6.2 Foracompletediscussiononinterferenceswithgraphite Other grades may be used, provided it is first ascertained that
furnace procedures, refer to Practice D 3919. the reagent is of sufficiently high purity to permit its use
6.3 Sodium is a common contaminant in many reagents. without lessening the accuracy of the determination.
The analyst must ensure that the quality of the reagent used in 8.2 Purity of Water— All references to water in this test
the procedure is sufficiently high to determine trace levels of method shall be understood to mean reagent water conforming
sodium. to Specification D 1193, Type I.
6.4 All plasticware and apparatus must be cleaned and 8.3 Sodium Solution, stock (1 mL = 1000 µg Na)—Dissolve
maintained to eliminate high background levels of sodium 2.542 g of sodium chloride in water and dilute to 1 L.
when determining trace levels. 8.4 Sodium Solution, intermediate (1 mL = 10.0 µg Na)—
6.5 Airborne particulates are a potential interference with Dilute 10.0 mL of stock sodium solution from 8.3 to 1 L with
the analysis of sodium by GFAAS. The user must ensure that water.
all plasticware and other equipment is capped or stored in air 8.5 Sodium Solution, standard (1 mL = 0.05 µg Na)—Dilute
tight containers. 5 mL of intermediate sodium solution from 8.4 to 1 L with
water.
7. Apparatus
NOTE 3—Alternatively, the analyst may purchase a commercially
7.1 AtomicAbsorption Spectrophotometer,withthecapabil-
available standard (1 mL = 1000 µg Na). Additional dilution will be
ity of setting the following instrumental parameters:
necessary to obtain the stock sodium solution concentration in 8.3.
Metal Wavelength, nm Slit width (SBW), nm
8.6 Argon, 99.99 % pure.
Sodium 589.0 0.5
NOTE 2—The manufacturer’s instructions should be followed for all
9. Sampling
instrument parameters.
9.1 Collect the sample in accordance with Practices D 1066
7.2 Hollow Cathode Lamp, for sodium.
and D 3370 or Specification D 1192.
7.2.1 Multielement hollow cathode lamps may be used if
9.2 Samples should be collected in polystyrene, TFE-
the analyst ensures the necessary sensitivity is available for the
fluorocarbon or polypropylene bottles only. Do not use glass or
low level determination.
polyethylene containers. The containers should be rinsed with
7.3 Graphite Furnace, capable of reaching temperatures
Type I water. The container should be stored prior to use by
sufficient to atomiz
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