1、Designation: D5997 96 (Reapproved 2009)D5997 15Standard Test Method forOn-Line Monitoring of Total Carbon, Inorganic Carbon inWater by Ultraviolet, Persulfate Oxidation, and MembraneConductivity Detection1This standard is issued under the fixed designation D5997; the number immediately following the
2、 designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers t
3、he on-line determination of total carbon (TC), inorganic carbon (IC), and total organic carbon(TOC) in water in the range from 0.5 g/L to 50 000 g/LgL of carbon. Higher carbon levels may be determined by suitableon-line dilution. This test method utilizes ultraviolet-persulfate oxidation of organic
4、carbon coupled with a CO2 selectivemembrane to recover the CO2 into deionized water. The change in conductivity of the deionized water is measured and related tocarbon concentration in the oxidized sample using calibration data. Inorganic carbon is determined in a similar manner withoutthe requireme
5、nt for oxidation. In both cases, the sample is acidified to facilitate CO2 recovery through the membrane. Therelationship between the conductivity measurement and carbon concentration can be described by a set of chemometric equationsfor the chemical equilibrium of CO2, HCO3, H H+, and OH OH, and th
6、e relationship between the ionic concentrations and theconductivity. The chemometric model includes the temperature dependence of the equilibrium constants and the specificconductances resulting in linear response of the method over the stated range of TOC. See Test Method D4519 for a discussionof t
7、he measurement of CO2 by conductivity.1.2 This test method has the advantage of a very high sensitivity detector that allows very low detection levels on relativelysmall volumes of sample. Also, the use of two measurement channels allows determination of IC in the sample independently oforganic carb
8、on. Isolation of the conductivity detector from the sample by the CO2 selective membrane results in a very stablecalibration with minimal interferences.1.3 This test method was used successfully with reagent water spiked with sodium carbonate and various organic compounds.This test method is effecti
9、ve with both deionized water samples and samples of high ionic strength. It is the users responsibilityto ensure the validity of this test method for waters of untested matrices.1.4 This test method is applicable only to carbonaceous matter in the sample that can be introduced into the reaction zone
10、. Theinlet system generally limits the maximum size of particles that can be introduced. Filtration may also be used to remove particles,however, this may result in removal of organic carbon if the particles contain organic carbon.1.5 The values stated in SI units are to be regarded as standard. No
11、other units of measurement are included in this standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicabilit
12、y of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1192 Guide for Equipment for Sampling Water and Steam in Closed Conduits (Withdrawn 2003)3D1193 Specification for Reagent WaterD2777 Practice for Determination of Precision and Bias
13、 of Applicable Test Methods of Committee D19 on Water1 This test method is under the jurisdiction of ASTM Committee D19 on Water and is the direct responsibility of Subcommittee D19.03 on Sampling Water andWater-Formed Deposits, Analysis of Water for Power Generation and Process Use, On-Line Water A
14、nalysis, and Surveillance of Water.Current edition approved Oct. 1, 2009May 1, 2015. Published November 2009August 2015. Originally approved in 1996. Last previous edition approved in 20002009as D5997 96 (2005).(2009). DOI: 10.1520/D5997-96R09.10.1520/D5997-15.2 For referencedASTM standards, visit t
15、heASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document
16、is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appro
17、priate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D3370 Practices for Sampling Water from Closed ConduitsD4519 T
18、est Method for On-Line Determination of Anions and Carbon Dioxide in High Purity Water by Cation Exchange andDegassed Cation Conductivity3. Terminology3.1 Definitions:3.1.1 For definitions of terms used in this test method, refer to Terminology D1129.3.2 Definitions of Terms Specific to This Standar
19、d:3.2.1 inorganic carbon (IC), ncarbon in the form of carbon dioxide, carbonate ion, or bicarbonate ion.3.2.2 refractory material, nthat which cannot be oxidized completely under the test method conditions.3.2.3 total carbon (TC), nthe sum of IC and TOC.3.2.4 total organic carbon (TOC), ncarbon in t
20、he form of organic compounds.4. Summary of Test Method4.1 FundamentalsCarbon can occur in water as inorganic and organic compounds. This test method can be used to makeindependent measurements of IC and TC and can also determine TOC as the difference between TC and IC. If IC is high relativeto TOC,
21、it is desirable to use a vacuum degassing unit to reduce the IC concentration to obtain meaningful TOC values bydifference.4.2 The basic steps of this test method are:4.2.1 Conversion of remaining IC to CO2 by action of acid,4.2.2 Removal of IC, if desired, by vacuum degassing,4.2.3 Split of flow in
22、to two streams to provide for separate IC and TC measurements,4.2.4 Oxidation of TC to CO2 by action of acid-persulfate aided by ultraviolet (UV) radiation in the TC channel,4.2.5 Detection of CO2 by passing each liquid stream over membranes that allow the specific passage of CO2 to high-puritywater
23、 where change in conductivity is measured, and4.2.6 Conversion of the conductivity detector signal to a display of carbon concentration in parts per million (ppm = mgL) orparts per billion (ppb = gL). The IC channel reading is subtracted from the TC channel reading to give a TOC reading.Adiagramof s
24、uitable apparatus is given in Fig. 1.5. Significance and Use5.1 This test method is useful for detecting and determining organic and inorganic carbon impurities in water from a variety ofsources including industrial water, drinking water, and waste water.5.2 Measurement of these impurities is of vit
25、al importance to the operation of various industries such as power, pharmaceutical,semiconductor, drinking water treatment, and waste treatment. Semiconductor and power applications require measurement of verylow organic carbon levels (TOC 18 Mohm-cm. If either the TC or IC channelmeasures 10 g/L, t
26、he resin may need replacement.14.4 The user should confirm that the unit is giving proper response using the sample matrix with compound types of interestand operating under the environmental extremes of interest.D5997 15515. Precision and Bias515.1 Since this test method involves continuous samplin
27、g and measurement, Practice D2777 is not applicable. As specified inthe method, theoretically prepared standards can be used to check the calibration of the analyzer. When measuring levels below500 g/L, g/L, it is difficult to prevent contamination unless on-line sampling is used. Background water l
28、evels should becharacterized and accounted for to prevent introduction of unacceptable bias. Accuracy of 63 % (15 g/L) or 60.5 g/L (15g/L) and relative sample standard deviations of 61 % (15 g/L) or 60.2 g/L (15 g/L) are typical for TOC depending on thematrix (especially IC level) and sample level.
29、Table 2 and Table 3 provide typical performance data at 500 and 25 000 gg/LLC.15.2 Fig. 2 shows instrument response for carbon versus carbon concentration over five orders of magnitude from 0.25 g/Lg/L C to 25 000 g/L C for two instruments calibrated at 25 000 g/L C. The limit of detection (LOD) for
30、 this test method wasestimated by plotting the standard deviation for each of the three lowest concentrations against the analyzed concentration.6 Fromthis data the y-intercept is considered to be the best estimate of the precision at zero concentration (S0). The S0 value was5 Supporting data have b
31、een filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:D19-1163. Contact ASTM CustomerService at serviceastm.org.6 Taylor, J. K., “Quality Assurance of Chemical Measurements,” Louis Publisher, Chelsea, MI, 1987, pp. 7882.NOTE 1Carbon standards prepared from
32、 sucrose in low TOC waterCalibration: 25 000 g/L potassium acid phthalateFIG. 2 Instrument Response Versus Carbon ConcentrationTABLE 4 Detection Limit StudyMeasurementTechniqueNumber ofRepetitions (n)ExpectedValue,g/LMeanMeasuredResponse,g/LStandardDeviation, g/Lg/LGrab from flask 10 25 159 25 143 4
33、3.3Grab from flask 10 495.9 487.1 0.793Grab from flask 10 50.00 50.89 0.279Direct on-line 8 15.68 15.70 0.084Direct on-line 9 6.359 6.996 0.091Grab from flask 10 4.990 5.463 0.102Direct on-line 10 0.519 0.488 0.037Direct on-line 9 0.227 0.223 0.014NOTE 1Sample: Sucrose in waterSample introduced by m
34、etering pump into continuous stream or asstandard addition to flaskCalibration: 25.0 103 g L C as potassium acid phthalate25.0 103 g L C as sodium carbonateD5997 156determined to be 0.020 g/L. The LOD is assigned as three times S0 or 0.060 g/L. This data supports the assigned limit ofquantitations (
35、LOQ) of 0.5 g/L. Measurements of TOC were determined by introducing a known amount of standard directly intoa continuous water sample using a metering pump or by preparing and analyzing flasks containing standards prepared usingvolumetric additions (see Table 4). The data was taken on several differ
36、ent days with each concentration level determined on asingle day. For continuous flow data, the baseline level of TOC was measured before and after the standard addition, and theaverage baseline TOC values were subtracted from the measured TOC values. For analyses taken from flasks, the baseline was
37、measured initially and then subtracted from the response. The number of repetitions of each sample analyzed in order to calculatethe standard deviations is given in Table 4.16. Keywords16.1 carbon; conductivity; inorganic carbon; membrane; on-line; total organic carbonTABLE 2 Precision and Bias at 5
38、00 g/L CTOC Response, g/L C489.7489.8490.5490.2491.5490.1490.6490.8491.8491.9average = 490.7error = 1.769 %standard deviation = 0.162 %D5997 157ANNEX(Mandatory Information)A1. BIBLIOGRAPHYA1.1 Godec, R.D., Kosenka, P.K., Hutte, R.S., “Method andApparatus for the Determination of Dissolved Carbon in
39、Water,” U.S.Patent No. 5,132,094 (July 21, 1992).A1.2 Godec, R., ONeill, K., Hutte, R., “New Technology for TOC Analysis in Water,” Ultrapure Water, Dec. 1992, pp. 1722.A1.3 Deak-Phillips, A., Rathgraber, K., Hutte, R., “On-Line Application of a New TOC Analyzer in the Power Industry,”Proceedings of
40、 the 1993 Chemistry On-Line Process Instrumentation Seminar, Clearwater, FL.A1.4 Barley, R., Hutte, R., ONeill, K., “Application of TOC Monitoring in Semiconductor Manufacturing,” Ultrapure Water,July/August 1994, pp. 2025.BIBLIOGRAPHY(1) Godec, R. D., Kosenka, P. K., and Hutte, R. S., “Method and A
41、pparatus for the Determination of Dissolved Carbon in Water,” U.S. Patent No.5,132,094 (July 21, 1992).(2) Godec, R., ONeill, K., and Hutte, R., “New Technology for TOC Analysis in Water,” Ultrapure Water, Dec. 1992, pp. 1722.(3) Deak-Phillips, A., Rathgraber, K., and Hutte, R., “On-Line Application
42、 of a New TOC Analyzer in the Power Industry,” Proceedings of the1993 Chemistry On-Line Process Instrumentation Seminar, Clearwater, FL.(4) Barley, R., Hutte, R., and ONeill, K., “Application of TOC Monitoring in Semiconductor Manufacturing,” Ultrapure Water, July/August 1994,pp. 2025.NOTE 1Sample:
43、499.5 g/L C as sucrose in DI waterCalibration: 25.0 10 3 g L C as potassium acid phthalate25.0 10 3 g L C as sodium carbonateZero: Low TOC (5 g/L C) DI waterTABLE 3 Precision and Bias at 25 000 g/L CTOC Response, g/L g/L C25 06325 11625 12625 14125 13125 15325 16625 21725 17725 193average = 25 148er
44、ror = 0.062 %standard deviation = 0.172 %NOTE 1Sample: 499.5 g/L C as sucrose in DI waterCalibration: 25.0 10 3 g L C as potassium acid phthalate25.0 10 3 g L C as sodium carbonateZero: Low TOC (5 g/L C) DI waterD5997 158ASTM International takes no position respecting the validity of any patent righ
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