ASTM D5996-05(2009)
(Test Method)Standard Test Method for Measuring Anionic Contaminants in High-Purity Water by On-Line Ion Chromatography
Standard Test Method for Measuring Anionic Contaminants in High-Purity Water by On-Line Ion Chromatography
SIGNIFICANCE AND USE
In the power-generation industry, high-purity water is used to reduce corrosion from anions, such as sulfate, chloride, and fluoride. These anions are known to be detrimental to materials of construction used in steam generators, reactor vessel internals and recirculation piping, heat exchangers, connective piping, and turbines. Most electric generating plants try to control these anions to 1.0 μg/L in the steam generator feed water. Some nuclear power plants have been able to control anion contaminants at less than 0.02 μg/L.
These anions and others cause low product yields in semiconductor manufacturing. They are also monitored and controlled at similarly low levels as in the electric power industry.
Low molecular weight organic acids (acetate, formate, propionate) have been detected in steam generator feed water. These low molecular weight organic materials are believed to be high-temperature degradation products of chemicals used to control cycle water pH and organic contaminants in cycle makeup water.
In the semiconductor industry, anion contaminants may come from the breakdown of low molecular weight organic materials by ultraviolet light radiation, which is frequently used to produce bacteria-free water. These organic compounds may also contribute to low product yield.
The production of high-purity water for process makeup and use frequently employs the use of demineralizers to remove unwanted anion contaminants. Also in the electric power industry, demineralizers are used in the process stream to maintain low levels of these contaminants. As such, it is important to monitor this process to ensure that water quality standards are being met. These processes can be monitored for the above-mentioned anions.
On-line measurements of these contaminants provide a greater degree of protection of the processes by allowing for frequent on-line measurement of these species. Early detection of contaminant ingress allows for quicker corrective action to locate, ...
SCOPE
1.1 This test method covers on-line analysis of high-purity water by the ion chromatography technique. This test method is applicable for measuring various anionic contaminants in high-purity water, typically in the range of 0.01 to 100 μg/L. This test method is used to determine the concentration of acetate, formate, chloride, fluoride, phosphate, nitrate, and sulfate in a continuously flowing sample. The range of the test method is only as good as the reagent water available for preparing standards. At extremely low concentrations, 1.0 μg/L, preparing standards is difficult, and extra care must be taken in their preparation. The sample may have to be conditioned from higher pressures and temperatures to conditions that are suitable for use by on-line instruments.
1.2 Online sample analysis of flowing streams does not lend itself to collaborative studies due to the nature of the sample and the possibility of contamination that may result from handling the sample as part of the collaborative study. Therefore this standard test method is not based on the results of a collaborative study but is intended to provide the best possible guidance for doing this type of analysis.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: D5996 − 05(Reapproved 2009)
Standard Test Method for
Measuring Anionic Contaminants in High-Purity Water by
On-Line Ion Chromatography
This standard is issued under the fixed designation D5996; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D1192Guide for Equipment for Sampling Water and Steam
in Closed Conduits (Withdrawn 2003)
1.1 This test method covers on-line analysis of high-purity
D1193Specification for Reagent Water
water by the ion chromatography technique. This test method
D2777Practice for Determination of Precision and Bias of
is applicable for measuring various anionic contaminants in
Applicable Test Methods of Committee D19 on Water
high-purity water, typically in the range of 0.01 to 100 µg/L.
D3370Practices for Sampling Water from Closed Conduits
This test method is used to determine the concentration of
D3864Guide for On-Line Monitoring Systems for Water
acetate, formate, chloride, fluoride, phosphate, nitrate, and
Analysis
sulfate in a continuously flowing sample.The range of the test
D4453Practice for Handling of High Purity Water Samples
method is only as good as the reagent water available for
D5542Test Methods for TraceAnions in High Purity Water
preparing standards. At extremely low concentrations, <1.0
by Ion Chromatography
µg/L, preparing standards is difficult, and extra care must be
D5810Guide for Spiking into Aqueous Samples
taken in their preparation. The sample may have to be
D5847Practice for Writing Quality Control Specifications
conditioned from higher pressures and temperatures to condi-
for Standard Test Methods for Water Analysis
tions that are suitable for use by on-line instruments.
1.2 Onlinesampleanalysisofflowingstreamsdoesnotlend
3. Terminology
itself to collaborative studies due to the nature of the sample
3.1 Fordefinitionsoftermsusedinthistestmethod,referto
and the possibility of contamination that may result from
Terminology D1129.
handling the sample as part of the collaborative study. There-
fore this standard test method is not based on the results of a 3.2 Definitions of Terms Specific to This Standard:
collaborative study but is intended to provide the best possible 3.2.1 analytical column, n—a column used to separate the
guidance for doing this type of analysis.
anions of interest.
1.3 This standard does not purport to address all of the 3.2.2 analytical column set, n—a combination of one or
safety concerns, if any, associated with its use. It is the
more guard columns followed by one or more analytical
responsibility of the user of this standard to establish appro- columns.
priate safety and health practices and determine the applica-
3.2.3 anion suppressor device, n—a device that is placed
bility of regulatory limitations prior to use.
between the analytical columns and the detector. Its purpose is
to inhibit detector response to the ionic constituents in the
2. Referenced Documents
eluant, so as to lower the detector background and at the same
2.1 ASTM Standards:
time enhance detector response to the ions of interest.
D1066Practice for Sampling Steam
3.2.4 breakthrough volume, n—the maximum sample vol-
D1129Terminology Relating to Water
ume that can be passed through a concentrator column before
the least tightly bound ion of interest is eluted. All of the
columns in series contribute to the overall capacity of the
This test method is under the jurisdiction ofASTM Committee D19 on Water
analytical column set.
and is the direct responsibility of Subcommittee D19.03 on Sampling Water and
Water-Formed Deposits,Analysis of Water for Power Generation and Process Use,
3.2.5 concentrator column, n—an ion exchange column
On-Line Water Analysis, and Surveillance of Water.
used to concentrate the ions of interest and thereby increase
Current edition approved Oct. 1, 2009. Published November 2009. Originally
method sensitivity.
approved in 1996. Last previous edition approved in 2005 as D5996–05. DOI:
10.1520/D5996-05R09.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5996 − 05 (2009)
3.2.6 eluant, n—theionicmobilephaseusedtotransportthe 5.4 In the semiconductor industry, anion contaminants may
sample through the analytical column. come from the breakdown of low molecular weight organic
materials by ultraviolet light radiation, which is frequently
3.2.7 guard column, n—acolumnusedbeforetheanalytical
used to produce bacteria-free water.These organic compounds
column to protect it from contaminants, such as particulate
may also contribute to low product yield.
matter or ionic species that may chemically foul the resins and
degrade their performance. 5.5 Theproductionofhigh-puritywaterforprocessmakeup
and use frequently employs the use of demineralizers to
3.2.8 ion chromatography, n—a form of liquid chromatog-
remove unwanted anion contaminants. Also in the electric
raphy in which ionic constituents are separated by ion ex-
power industry, demineralizers are used in the process stream
change followed by a suitable detection means.
to maintain low levels of these contaminants. As such, it is
3.2.9 resolution, n—the ability of an analytical column to
important to monitor this process to ensure that water quality
separate constituents under specific test conditions.
standards are being met.These processes can be monitored for
the above-mentioned anions.
4. Summary of Test Method
5.6 On-line measurements of these contaminants provide a
greater degree of protection of the processes by allowing for
4.1 A continuously flowing sample is injected into the
frequent on-line measurement of these species. Early detection
instrument through a sample injection valve. The sample is
of contaminant ingress allows for quicker corrective action to
pumped through a concentrator column where the anions of
locate,reduce,oreliminate,orcombinationthereof,thesource.
interest are collected on ion-exchange resin. After a suitable
Grab samples will not provide the same level of protection
volume of sample has been passed through the concentrator
because of their intermittent nature and the longer time
column, sample flow is diverted and an eluant is pumped
required to obtain and then analyze the sample.
throughtheconcentratorcolumntoremovethetrappedanions.
This eluant then flows through an analytical column set where
5.7 Additionally, on-line monitoring significantly reduces
theanionsareseparatedbasedontheretentioncharacteristicof
the potential for contamination of high-purity water samples, a
each anion relative to the eluant used. The eluant stream
significant problem when sampling and testing high-purity
containing the anions of interest passes through a suppressor
water.
device where the cations from the eluant are exchanged for
6. Interferences
hydrogen ions, converting the anions to their acid form. After
the suppressor device, the eluant solution passes through a
6.1 When working with low concentration samples, blanks,
conductivity detector where the separated anions are detected.
and standards, contamination can be a serious problem. Ex-
Detectionlimitsfortheanionsareenhancedbecausetheanions
treme care must be exercised in all phases of this test method.
are in the acid form rather than the salt.
6.2 Improper sample line material or sample lines that have
4.2 The anions are identified based on the retention time as
not been properly conditioned can give results that may not be
compared to known standards. By measuring peak height or
truly representative of the process stream. Absorption/
area and comparing the detector response to known standards,
desorption of anions on sample line wall deposits can change
the anions can be quantified.
analytical results. Maintaining a minimum sample flow of 1.8
m/s(6ft/s)willminimizedepositbuilduponsamplelinewalls,
5. Significance and Use
reducing the potential for absorption/desorption of anions.
5.1 In the power-generation industry, high-purity water is 6.3 A single anion present at a concentration significantly
usedtoreducecorrosionfromanions,suchassulfate,chloride, higher than other anions could mask closely adjacent peaks on
and fluoride. These anions are known to be detrimental to the chromatogram.
materials of construction used in steam generators, reactor
6.4 Low breakthrough volumes may be experienced when
vessel internals and recirculation piping, heat exchangers,
continuouslymonitoringforanionsinwaterthathashaditspH
connectivepiping,andturbines.Mostelectricgeneratingplants
raised by ammonia, morpholine, or other additives. This
try to control these anions to <1.0 µg/Lin the steam generator
interference can be eliminated by taking the sample from the
feed water. Some nuclear power plants have been able to
effluent of a cation resin column.
control anion contaminants at less than 0.02 µg/L.
6.5 Identification of the anion is based on retention time of
5.2 These anions and others cause low product yields in
the anion of interest. An interfering anion having the same
semiconductor manufacturing. They are also monitored and
retention time as one of the anions of interest will result in
controlled at similarly low levels as in the electric power
erroneously high values for that anion.
industry.
6.6 When loading a concentrator column, high concentra-
5.3 Low molecular weight organic acids (acetate, formate, tions of interfering anions may cause low breakthrough vol-
propionate) have been detected in steam generator feed water. umes of other anions. These interfering anions may act as an
These low molecular weight organic materials are believed to eluantanddisplaceotheranionsfromtheconcentratorcolumn.
behigh-temperaturedegradationproductsofchemicalsusedto SeeAnnexA1todeterminebreakthroughvolume.Donotload
control cycle water pH and organic contaminants in cycle a sample volume greater than 80% of the breakthrough
makeup water. volume.
D5996 − 05 (2009)
7. Apparatus 8.5 Fluoride Solution, Stock (1.00 mL=1.00 mg F)—Dry
sodiumfluorideat110°Cfor2 60.5handcoolinadesiccator.
7.1 Ion chromatograph with the following components:
Dissolve 2.210 g of dried salt in water and dilute to 1 L.
7.1.1 Eluant Introduction System—The wetted portion of
8.6 Acetate Solution, Stock (1.00 mL=1.00 mg acetate)—
the eluant pump should be nonmetallic or of a corrosion-
Dissolve 1.389 g of sodium acetate in water and dilute to 1 L
resistantmetaltopreventcontaminationofthechromatography
with water. Store in a brown glass bottle with a TFE-
columns.
fluorocarbon lined cap in a refrigerator.
7.1.2 Sample Injection System—The wetted portion of the
sample pump should be nonmetallic or of a corrosion-resistant
8.7 Formate Solution, Stock (1.00 mL=1 mg formate)—
metal to prevent metal contamination of the chromatography
Dissolve 1.511 g sodium formate in water and dilute to 1 L
columns.
with water. Store in a brown glass bottle with a TFE-
7.1.3 Anion Suppressor Device.
fluorocarbon lined cap in a refrigerator.
7.1.4 Conductivity Cell, low dead volume (1 µL). Tempera-
8.8 Chloride Solution, Stock (1.00 mL=1.00 mg Cl)—Dry
ture compensated or corrected flow through conductivity
sodium chloride (NaCl) for 2 6 0.5 h at 110°C and cool in a
detectorshouldbecapableofmeasuringconductivityfrom0to
desiccator. Dissolve 1.648 g of the dry salt in water and dilute
1000 µS/cm. If temperature controlled conductivity detector is
to1L.
used, temperature control should be at 60.5°C or better.
8.9 Phosphate Solution, Stock (1.00 mL=1.00 mg PO )—
7.1.5 Suppressor Device Regenerant System—Some manu-
Dissolve 1.433 g of potassium dihydrogen phosphate
facturers provide integrated regenerant systems that reduce the
(KH PO ) in water and dilute to 1 L with water.
2 4
consumption of eluant. Electrochemical suppressor regenerant
systems can be used, eliminating the need to prepare regener- 8.10 Sulfate Solution, Stock(1.00mL=1.00mgSO )—Dry
ant solutions. sodium sulfate for 2 6 0.5 h at 110°C and cool in a desiccator.
Dissolve 1.479 g of the dried salt in water and dilute to 1 L.
8. Reagents
8.11 Nitrate Solution, Stock (1.00 mL=1.00 mg NO )—
Dryapproximately2gofsodiumnitrate(NaNO )at105°Cfor
8.1 Purity of Reagents—Reagent grade chemicals shall be
48 h. Dissolve exactly 1.371 g of the dried salt in water and
used in all tests. Unless otherwise indicated, it is intended that
dilute to 1 L with water.
all reagents conform to the specifications of the Committee on
Analytical Reagents of theAmerican Chemical Society where
8.12 Anion Intermediate Solutions—Prepare a 1000 µg/L
such specifications are available. Other grades may be used,
standard of each anion by diluting 1.00 mL of each stock
provided it is first ascertained that the reagent is of sufficiently
solution to 1 L. If acetate, formate, or phosphate are included
high purity to permit its use without lessening the accuracy of
in the standard, the solution must be prepared daily. It is
the determination.
recommendedthatthesestandardsbepreparedseparatelyfrom
the rest of the anions.
8.2 Purity of Water—Unless otherwise indicated, reference
to water shall be understood to mean reagent water as defined
8.13 Anion Working Solutions—Prepare a blank and at least
by Specification D1193 Type 1 and shall contain less than 0.2
three different working solutions from the anion intermediate
µg/Loftheanionsofinterest.Freshlypreparedwatershouldbe
solution,containingtheanionsofinterest.Prepareindedicated
used for making the low-level standards used for calibration.
volumetric flasks and transfer to sample containers in accor-
Detection limits will be limited by the purity of the water and
dance with Practice D4453. Prepare fresh daily. The range of
reagents used to make standards. The purity of the water used
the working solutions prepared should bracket the analytical
shall be checked by the use of Test Methods D5542.
range of interest.Atypical range would be 5, 10, and 25 µg/L
for each anion or consistent with analytical range of interest.
8.3 Prepare eluant for the specific columns used and for the
Systems equipped with sample preparation modules are ca-
anions of interest in accorda
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
An American National Standard Designation: D5996 – 05 (Reapproved 2009)
Designation:D 5996–96 (Reapproved 2000)
Standard Test Method for
Measuring Anionic Contaminants in High-Purity Water by
On-Line Ion Chromatography
This standard is issued under the fixed designation D5996; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1This test method covers on-line analysis of high-purity water by the ion chromatography technique. This test method is
applicable for measuring various anionic contaminants in high-purity water, typically in the range of 0.02 to 100 µg/L. This test
method is used to determine the concentration of acetate, formate, chloride, fluoride, phosphate, nitrate, and sulfate in a
continuously flowing sample.The range of the test method is only as good as the reagent water available for preparing standards.
Atextremelylowconcentrations,<1.0µg/L,preparingstandardsisdifficult,andextracaremustbetakenintheirpreparation.The
sample may have to be conditioned from higher pressures and temperatures to conditions that are suitable for use by on-line
instruments. The range of the test method is only as good as the reagent water available for standard preparation.
1.2
1.1 This test method covers on-line analysis of high-purity water by the ion chromatography technique. This test method is
applicable for measuring various anionic contaminants in high-purity water, typically in the range of 0.01 to 100 µg/L. This test
method is used to determine the concentration of acetate, formate, chloride, fluoride, phosphate, nitrate, and sulfate in a
continuously flowing sample.The range of the test method is only as good as the reagent water available for preparing standards.
Atextremelylowconcentrations,<1.0µg/L,preparingstandardsisdifficult,andextracaremustbetakenintheirpreparation.The
sample may have to be conditioned from higher pressures and temperatures to conditions that are suitable for use by on-line
instruments.
1.2 Online sample analysis of flowing streams does not lend itself to collaborative studies due to the nature of the sample and
thepossibilityofcontaminationthatmayresultfromhandlingthesampleaspartofthecollaborativestudy.Thereforethisstandard
test method is not based on the results of a collaborative study but is intended to provide the best possible guidance for doing this
type of analysis.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
D1066 Practice for Sampling Steam
D1129 Terminology Relating to Water
D1192 SpecificationGuide for Equipment for Sampling Water and Steam in Closed Conduits
D1193 Specification for Reagent Water
D2777 Practice for the Determination of Precision and Bias of Applicable Test Methods of Committee D-19D19 on Water
D3370 Practices for Sampling Water from Closed Conduits
D3864 Guide for Continual On-Line Monitoring Systems for Water Analysis
D4453 Practice for Handling of Ultra-Pure Water Samples
D5542 Test Methods for TraceAnions in High Purity Water by Ion Chromatography Test Methods for TraceAnions in High
Purity Water by Ion Chromatography
D5810 Guide for Spiking into Aqueous Samples
This test method is under the jurisdiction of ASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.03 on Sampling of Water and
Water-Formed Deposits, Surveillance of Water, and Flow Measurement of Water.
Current edition approved July 10, 1996. Published October 1996.on Sampling Water and Water-Formed Deposits, Analysis of Water for Power Generation and Process
Use, On-Line Water Analysis, and Surveillance of Water.
Current edition approved Oct. 1, 2009. Published November 2009. Originally approved in 1996. Last previous edition approved in 2005 as D5996–05. DOI:
10.1520/D5996-05R09.
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.For Annual Book of ASTM Standards
, Vol 11.01.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.
D5996 – 05 (2009)
D5847 Practice for Writing Quality Control Specifications for Standard Test Methods for Water Analysis
3. Terminology
3.1 For definitions of terms used in this test method, refer to Terminology D 1129D1129.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 analytical column,analytical column, n—a column used to separate the anions of interest.
3.2.2 analytical column set,analytical column set, n—a combination of one or more guard columns followed by one or more
analytical columns.
3.2.3 anion suppressor device,anion suppressor device, n—a device that is placed between the analytical columns and the
detector. Its purpose is to inhibit detector response to the ionic constituents in the eluant, so as to lower the detector background
and at the same time enhance detector response to the ions of interest.
3.2.4 breakthrough volume,breakthrough volume, n—the maximum sample volume that can be passed through a concentrator
column before the least tightly bound ion of interest is eluted.All of the columns in series contribute to the overall capacity of the
analytical column set.
3.2.5 concentratorcolumn,concentratorcolumn,n—anionexchangecolumnusedtoconcentratetheionsofinterestandthereby
increase method sensitivity.
3.2.6 eluant,eluant, n—the ionic mobile phase used to transport the sample through the analytical column.
3.2.7 guard column,guard column, n—a column used before the analytical column to protect it from contaminants, such as
particulate matter or ionic species that may chemically foul the resins and degrade their performance.
3.2.8 ion chromatography,ion chromatography, n—a form of liquid chromatography in which ionic constituents are separated
by ion exchange followed by a suitable detection means.
3.2.9 resolution,resolution, n—the ability of an analytical column to separate constituents under specific test conditions.
4. Summary of Test Method
4.1 A continuously flowing sample is injected into the instrument through a sample injection valve. The sample is pumped
throughaconcentratorcolumnwheretheanionsofinterestarecollectedonion-exchangeresin.Afterasuitablevolumeofsample
has been passed through the concentrator column, sample flow is diverted and an eluant is pumped through the concentrator
columntoremovethetrappedanions.Thiseluantthenflowsthroughananalyticalcolumnsetwheretheanionsareseparatedbased
on the retention characteristic of each anion relative to the eluant used. The eluant stream containing the anions of interest passes
throughasuppressordevicewherethecationsfromtheeluantareexchangedforhydrogenions,convertingtheanionstotheiracid
form. After the suppressor device, the eluant solution passes through a conductivity detector where the separated anions are
detected. Detection limits for the anions are enhanced because the anions are in the acid form rather than the salt.
4.2 The anions are identified based on the retention time as compared to known standards. By measuring peak height or area
and comparing the detector response to known standards, the anions can be quantified.
5. Significance and Use
5.1 In the power-generation industry, high-purity water is used to reduce corrosion from anions, such as sulfate, chloride, and
fluoride. These anions are known to be detrimental to materials of construction used in steam generators, reactor vessel internals
and recirculation piping, heat exchangers, connective piping, and turbines. Most electric generating plants try to control these
anions to <1.0 µg/L in the steam generator feed water. Some nuclear power plants have been able to control anion contaminants
at less than 0.02 µg/L.
5.2 These anions and others cause low product yields in semiconductor manufacturing.They are also monitored and controlled
at similarly low levels as in the electric power industry.
5.3 Lowmolecularweightorganicacids(acetate,formate,propionate)havebeendetectedinsteamgeneratorfeedwater.These
low molecular weight organic materials are believed to be high-temperature degradation products of chemicals used to control
cycle water pH and organic contaminants in cycle makeup water.
5.4 In the semiconductor industry, anion contaminants may come from the breakdown of low molecular weight organic
materialsbyultravioletlightradiation,whichisfrequentlyusedtoproducebacteria-freewater.Theseorganiccompoundsmayalso
contribute to low product yield.
5.5 The production of high-purity water for process makeup and use frequently employs the use of demineralizers to remove
unwanted anion contaminants.Also in the electric power industry, demineralizers are used in the process stream to maintain low
levels of these contaminants.As such, it is important to monitor this process to ensure that water quality standards are being met.
These processes can be monitored for the above-mentioned anions.
5.6 On-linemeasurementsofthesecontaminantsprovideagreaterdegreeofprotectionoftheprocessesbyallowingforfrequent
on-linemeasurementofthesespecies.Earlydetectionofcontaminantingressallowsforquickercorrectiveactiontolocate,reduce,
or eliminate, or combination thereof, the source. Grab samples will not provide the same level of protection because of their
intermittent nature and the longer time required to obtain and then analyze the sample.
5.7 Additionally, on-line monitoring significantly reduces the potential for contamination of high-purity water samples, a
significant problem when sampling and testing high-purity water.
D5996 – 05 (2009)
6. Interferences
6.1 When working with low concentration samples, blanks, and standards, contamination can be a serious problem. Extreme
care must be exercised in all phases of this test method.
6.2 Impropersamplelinematerialorsamplelinesthathavenotbeenproperlyconditionedcangiveresultsthatmaynotbetruly
representative of the process stream.Absorption/desorption of anions on sample line wall deposits can change analytical results.
Maintainingaminimumsampleflowof1.8m/s(6ft/s)willminimizedepositbuilduponsamplelinewalls,reducingthepotential
for absorption/desorption of anions.
6.3 A single anion present at a concentration significantly higher than other anions could mask closely adjacent peaks on the
chromatogram.
6.4 LowbreakthroughvolumesmaybeexperiencedwhencontinuouslymonitoringforanionsinwaterthathashaditspHraised
byammonia,morpholine,orotheradditives.Thisinterferencecanbeeliminatedbytakingthesamplefromtheeffluentofacation
resin column.
6.5 Identificationoftheanionisbasedonretentiontimeoftheanionofinterest.Aninterferinganionhavingthesameretention
time as one of the anions of interest will result in erroneously high values for that anion.
6.6 When loading a concentrator column, high concentrations of interfering anions may cause low breakthrough volumes of
other anions. These interfering anions may act as an eluant and displace other anions from the concentrator column. See Annex
A1 to determine breakthrough volume. Do not load a sample volume greater than 80% of the breakthrough volume.
7. Apparatus
7.1 Ion chromatograph with the following components:
7.1.1 Eluant Introduction System—The wetted portion of the eluant pump should be nonmetallic or of a corrosion-resistant
metal to prevent contamination of the chromatography columns.
7.1.2 Sample Injection System—Thewettedportionofthesamplepumpshouldbenonmetallicorofacorrosion-resistantmetal
to prevent metal contamination of the chromatography columns.
7.1.3 Anion Suppressor Device.
7.1.4 Conductivity Cell, low dead volume (1 µL). Temperature compensated or corrected flow through conductivity detector
should be capable of measuring conductivity from 0 to 1000 µS/cm. If temperature controlled conductivity detector is used,
temperature control should be at 60.5°C or better.
7.1.5 Suppressor Device Regenerant System—Some manufacturers provide integrated regenerant systems that reduce the
consumption of eluant. Electrochemical suppressor regenerant systems can be used, eliminating the need to prepare regenerant
solutions.
8. Reagents
8.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where such
specificationsareavailable. Othergradesmaybeused,provideditisfirstascertainedthatthereagentisofsufficientlyhighpurity
to permit its use without lessening the accuracy of the determination.
8.2 Purity of Water—Unless otherwise indicated, reference to water shall be understood to mean reagent water as defined by
Specification D 1193D1193 Type 1 and shall contain less than 0.2 µg/L of the anions of interest. Freshly prepared water should
be used for making the low-level standards used for calibration. Detection limits will be limited by the purity of the water and
reagents used to make standards. The purity of the water used shall be checked by the use of Test Methods D 5542D5542.
8.3 Prepare eluant for the specific columns used and for the anions of interest in accordance with manufacturer’s directions.
8.4 Prepare regenerant for the specific suppressor used in accordance with the manufacturer’s directions if required.
NOTE 1—There are numerous combinations of analytical columns, suppressors, eluants, and regenerants that may be used with this method. It is not
practicable to list all the combinations. Users should use the appropriate combination of concentrator column, analytical column, suppressor, eluant, and
regenerant to achieve the desired resolution and detection.
8.5 Fluoride Solution, Stock (1.00 mL = 1.00 mg F)—Dry sodium fluoride at 110°C for 2 6 0.5 h and cool in a desiccator.
Dissolve 2.210 g of dried salt in water and dilute to 1 L.
8.6 Acetate Solution, Stock (1.00 mL = 1.00 mg acetate)—Dissolve 1.389 g of sodium acetate in water and dilute to 1 L with
water. Store in a brown glass bottle wi
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