Standard Test Method for On-Line Measurement of Residue After Evaporation of High-Purity Water

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1.1 This test method covers the determination of dissolved organic and inorganic matter and colloidal material found in high-purity water used in the semiconductor, aerospace, and other industries. This material is referred to as residue after evaporation (RAE). The range of the test method is from 0.1 g/L(ppb) to 20 mg/L (ppm).
1.2 This test method uses a continuous, real time monitoring technique to measure the concentration of RAE. A pressurized sample of high-purity water is supplied to the test method's apparatus continuously through ultra-clean fittings and tubing. Contaminants from the atmosphere are therefore prevented from entering the sample. General information on the test method and a literature review on the continuous measurement of RAE has been published.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.4 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. For specific hazards statements, see Section 8.

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Publication Date
14-Sep-1994
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ASTM D5544-94(2004) - Standard Test Method for On-Line Measurement of Residue After Evaporation of High-Purity Water
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
An American National Standard
Designation:D5544–94(Reapproved2004)
Standard Test Method for
On-Line Measurement of Residue After Evaporation of High-
Purity Water
This standard is issued under the fixed designation D5544; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope Applicable Methods of Committee D19 on Water
D3370 PracticesforSamplingWaterfromClosedConduits
1.1 This test method covers the determination of dissolved
D3864 Practice for Continual On-line Monitoring Systems
organic and inorganic matter and colloidal material found in
for Water Analysis
high-purity water used in the semiconductor, aerospace, and
D3919 Practice for Measuring Trace Elements in Water by
other industries. This material is referred to as residue after
Graphite Furnace Atomic Absorption Spectrophotometry
evaporation (RAE). The range of the test method is from 0.1
E 1184 Practice for Electrothermal (Graphite Furnace)
µg/L(ppb) to 20 mg/L (ppm).
Atomic Absorption Analysis
1.2 Thistestmethodusesacontinuous,realtimemonitoring
technique to measure the concentration of RAE.Apressurized
3. Terminology
sample of high-purity water is supplied to the test method’s
3.1 Definitions—For definitions of terms used in this test
apparatus continuously through ultra-clean fittings and tubing.
method, refer to Terminology D1129.
Contaminants from the atmosphere are therefore prevented
3.2 Definitions of Terms Specific to This Standard:
from entering the sample. General information on the test
3.2.1 aerosol, n—any solid or liquid particles, with a
methodandaliteraturereviewonthecontinuousmeasurement
2 nominal size range from 10 nm to 100 µm, suspended in a gas
of RAE has been published.
(usually air).
1.3 The values stated in SI units are to be regarded as the
3.2.2 colloidal suspension, n— any material in suspension
standard. The values given in parentheses are for information
(for example, silica) with a nominal particle size less than 100
only.
nm.
1.4 This standard does not purport to address all of the
3.2.3 condensation nucleus counter (CNC), n—instrument
safety concerns, if any, associated with its use. It is the
for detecting very small aerosol particles in a size range from
responsibility of the user of this standard to establish appro-
approximately 10 nm to 2 to 3 µm. The CNC cannot differen-
priate safety and health practices and determine the applica-
tiate between particles of varying size within this size range; it
bility of regulatory limitations prior to use.Forspecifichazards
reports the number of particles with a size greater than that
statements, see Section 8.
defined by its detection efficiency curve. Detection is indepen-
2. Referenced Documents dent of particle composition.
3.2.4 detection effıciency, n— in this test method, detection
2.1 ASTM Standards:
efficiencyrepresentsacurverelatingparticlesizetoacounter’s
D1129 Terminology Relating to Water
ability to detect that size.
D1193 Specification for Reagent Water
3.2.5 diffusion screen, n—a fine mesh screen used to filter
D2777 Practice for Determination of Precision and Bias of
residue particles of a particular size.
3.2.6 high-purity water, n—within the context of this test
method, high-purity water is defined as water containing
This test method is under the jurisdiction ofASTM Committee D19 on Water
residue after evaporation in the range from 0.1 µg/L to 20
and is the direct responsibility of Subcommittee D19.03 on Sampling of Water and
Water-Formed Deposits,Analysis of Water for Power Generation and Process Use,
mg/L.
On-Line Water Analysis, and Suveillance of Water.
3.2.7 polydisperse, adj—a size population, in this case of
Current edition approved Sept. 15, 1994. Published November 1994.
2 aerosol particles, composed of many different sizes; the oppo-
Blackford, D. B., and Kerrick, T. A., Proceeding of Microcontamination ’91,
site of monodisperse, a distribution of just one size.
San Jose, CA, 1991, pp. 39–51. Published by Canon Communications Inc., 3340
Ocean Park Blvd., Suite 1000, Santa Monica, CA 90405.
3.2.8 realtime, n—the time that an event is occurring plus
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
the response time; in this case, the response time is 3 to 5 min.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Therefore,contaminationisrecorded3to5minafteritoccurs.
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.
D5544–94 (2004)
3.2.9 residue after evaporation, n—contaminantsremaining manganese, ammonium, bicarbonates, sulfates, nitrates, chlo-
after all water is evaporated; sometimes known as nonvolatile ride and fluoride ions, ferric and ferrous ions, and silicates;
residue or total dissolved and suspended solids. dissolved organic substances such as pesticides, herbicides,
plasticizers, styrene monomers, deionization resin material;
4. Summary of Test Method
andcolloidalsuspensionssuchassilica.Whilethistestmethod
4.1 This test method consists of continuously removing a
facilitates the monitoring of these contaminants in high-purity
representative sample of high-purity water from a pressurized
water, in real time, with one instrument, this test method is not
supply line (refer to Practices D3370, Practice C on Continual
capable of identifying the various sources of residue contami-
Sampling, and Practice D3864). The temperature of the
nation or detecting dissolved gases or suspended particles.
incominghigh-puritywatershouldideallybeatroomtempera-
5.2 Thistestmethodiscalibratedusingweighedamountsof
ture, but not more than 50°C. The high-purity water is
an artificial contaminant (potassium chloride). The density of
subsequently cooled to a constant temperature of 18°C. An
potassiumchlorideisreasonablytypicalofcontaminantsfound
atomizer is supplied with the cooled high-purity water at a
in high-purity water; however, the response of this test method
constantflowrate,andasourceofcompressedair,ornitrogen,
is clearly based on a response to potassium chloride. The
ataconstantflowrateandpressure,togenerateastableaerosol
response to actual contaminants found in high-purity water
of high-purity water droplets. Under these conditions, the may differ from the test method’s calibration.This test method
atomizer produces a polydisperse size distribution of droplets
is not different from many other analytical test methods in this
withamediansizeofapproximately1µm,andaconcentration respect.
7 12
of approximately 10 droplets/s, or 10 droplets/mL
5.3 Together with other monitoring methods, this test
4.2 The droplets enter a drying column; are rapidly mixed method is useful for diagnosing sources of RAE in ultra-pure
withdried,filtered,heated(normallyat120°C)compressedair,
water systems. In particular, this test method can be used to
or nitrogen; and dried within the first few centimetres of the detect leakages such as colloidal silica breakthrough from the
drying column. The temperature of the drying column can be
effluentofaprimaryanionormixed-beddeionizer.Inaddition,
set at lower temperatures (95, 70, or 45°C) if information
thistestmethodhasbeenusedtomeasuretherinse-uptimefor
concerning the dissolved organic fraction of residue is re-
newliquidfiltersandhasbeenadaptedforbatch-typesampling
quired. Each atomizer droplet produces a particle of nonvola-
(this adaptation is not described in this test method).
tile residue. As the residue particles emerge from the drying
5.4 Obtaining an immediate indication of contamination in
column, a small percentage is removed and passed through a
high-purity water has significance to those industries using
diffusion screen before being counted by a condensation
high-purity water for manufacturing components; production
nucleus counter (CNC). Different combinations of diffusion
can be halted immediately to correct a contamination problem.
screens modify the detection efficiency of the CNC, allowing
The biomedical and power-generating industries will also
detection in the 0.1-µg/L to 20-mg/L range.
benefit from this information.
4.3 The CNC works as follows: The residue particles enter
6. Apparatus
a saturator and pass through a heated, volatile liquid-soaked
6.1 The schematic arrangement of the system is shown in
wick. The wick dips into the liquid reservoir and continually
Fig.1.Theapparatusisavailableasacompleteinstrument, or
drawsupliquidthroughaninclinedtube.Theliquidevaporates
the individual components described in 6.4, 6.6, and 6.7 can
and saturates the aerosol stream with vapor. N-butyl alcohol
be purchased separately.
has been used successfully as the volatile liquid in this test
6.2 Flow Controller, made of a non-contaminating material
method. The vapor-saturated aerosol passes into a vertical
such as perfluoroalkoxy (PFA), necessary to supply the atom-
condenser tube, cooled by a thermoelectric device. The vapor
izer with high-purity water at the desired flow rate. The flow
cools, becomes super-saturated, and begins to condense on the
controller must contain a pressure regulator to ensure that
particle nuclei to form large droplets that can then be counted
water is delivered to the atomizer at a stable flow rate, despite
with a relatively simple optical particle counter. A more
external fluctuations. High-purity water must be delivered to
elaborate description of the CNC’s method for distinguishing
the flow controller and atomizer through ultra-clean tubes and
between clean and dirty water is described in Appendix X1.
fittings made from PFA polytetrafluor-oethylene. Atomizers
4.4 A calibration technique (described in detail in Section
usually require a very low flow rate, approximately 1 mL/min,
10) uses concentration standards of high-purity potassium
for efficient operation. However, such a low flow rate is
chloride (KCl) to convert the CNC count concentration in
inadequate for routine monitoring because it results in a long
particles per cubic centimetre into RAE concentration in
response time. This test method is designed to overcome the
microgramsperlitreormilligramsperlitre.Agraphitefurnace
problem of long response times by using a flow controller to
atomicabsorptionspectrometer(GFAAS)canbeusedtocheck
deliver approximately 70 mL/min of high-purity water to the
the concentration of KCl in this test method standard (see
monitoring site and then to divert 1 mL/min of the flow to the
Practices D3919 and E1184).
atomizerthroughashorttube.Thisshorttubefacilitatesashort
5. Significance and Use
response time.
5.1 Even so-called high-purity water will contain contami-
nants. While not always present, these contaminants may
Available from TSI Inc., 500 Cardigan Rd., Shoreview, MN 55126.
contribute one or more of the following: dissolved active ionic
Available from Particle Measuring Systems, 5475 Airport Blvd., Boulder, CO
substances such as calcium, magnesium, sodium, potassium, 80301.
D5544–94 (2004)
FIG. 1 Schematic Diagram of Apparatus Required for This Test Method
6.3 Cooling Block,necessarytocoolthewaterandmaintain (referred to as a 400 mesh in the Tyler equivalent designation)
it at a stable temperature before it enters the atomizer (18°C is
has worked well in this test method.
adequate). The cooling block incorporates a thermoelectric
6.7 Condensation Nucleus Counter (CNC), containing a
devicecapableofmaintainingthecoolingblockattherequired
saturator, condenser, and optical particle counter to enlarge the
temperature.
particlestoauniformsizeandcounttheminparticlespercubic
6.4 Atomizer, required to produce a polydisperse size dis-
centimetre. The flow rate through the CNC is 2.8 L/min.
tributionofdropletswithamediansizeofapproximately1µm
7 6.7.1 Inside the saturator is a wick soaked in a volatile
and a concentration of approximately 10 droplets/s. The
liquid.Thewickdipsintoaliquidreservoiranddrawsupliquid
atomizer must be supplied with clean, dried filtered com-
continuallythroughaninclinedtube.Theliquidevaporatesand
pressed air or nitrogen and must be machined from a material
saturates the aerosol stream with vapor.
that will not contaminate the high-purity water. Passivated 316
stainless steel has been used successfully in this test method. 6.7.2 The vapor-saturated aerosol passes into a vertical
Details of how to passivate stainless steel can be found in the
condenser tube, cooled by a thermoelectric device. Aerosol
Metal Finishing Guidebook.
particles of a certain size and above (nominally 10-nm diam-
6.5 Mixing Chamber and Drying Column, for mixing the
eter)actasnucleationsitesuponwhichthevaporcancondense
water droplets from the atomizer with dried, heated (at 120°C
to form droplets (nominally 10-µm diameter). Droplets pass
or, if required, 95, 70, or 45°C) dilution air or nitrogen. The
from the condenser tube through a nozzle into the optical
water droplets and dilution air pass through a drying column
detector.
that evaporates all of the water from the droplets. The residue
6.7.3 TheCNC’sfocusingopticsconsistofalaserdiodeand
from each droplet is left as a particle. A drying column
beam-shaping optics. This combination forms a beam of laser
approximately 2.5 cm in diameter and 30 cm in length has
light above the aerosol exit nozzle. The sensor’s collecting
worked well in this test method, with a ratio of dilution air to
optics collect the light scattered by the droplets and focus this
atomizer air of approximately 10:1.
light onto a low-noise photo-detector.
6.6 Diffusion Screens—Fifty-millimetre diameter diffusion
screensmadeofafinestainlesssteelwireclothusedtoshiftthe
7. Reagents and Materials
detectionefficiencyoftheCNCtolargersizes.Wireclothwith
awirediameterof25µmandasquareweaveopeningof38µm
7.1 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
Metal Finishing Guidebook, Elsevier Science, New York, NY, 60th ed., 1992. Analytical Reagents of theAmerican Chemical Society where
D5544–94 (2004)
such specifications are available. Other grades may be used, fluctuations will affect the size of water droplets produced by
provided it is first ascertained that the reagent is of sufficiently the atomizer, making the calibration inaccurate.
high purity to permit its use without lessening the accuracy of 9.4 The at
...

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