1、Designation: G144 01 (Reapproved 2014)Standard Test Method forDetermination of Residual Contamination of Materials andComponents by Total Carbon Analysis Using a HighTemperature Combustion Analyzer1This standard is issued under the fixed designation G144; the number immediately following the designa
2、tion 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 the deter
3、mination of residualcontamination in an aqueous sample by the use of a totalcarbon (TC) analyzer. When used in conjunction with PracticeG131 and G136, this procedure may be used to determine thecleanliness of systems, components, and materials requiring ahigh level of cleanliness, such as oxygen sys
4、tems. Thisprocedure is applicable for aqueous-based cleaning and sam-pling methods only.1.2 This test method is not suitable for the evaluation ofparticulate contamination, or contaminants that are not solublein or that do not form an emulsion with water.1.3 This standard does not purport to address
5、 all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1193 Specificati
6、on for Reagent WaterD2579 Test Method for Total Organic Carbon in Water(Withdrawn 2002)3F331 Test Method for Nonvolatile Residue of Solvent Ex-tract from Aerospace Components (Using Flash Evapora-tor)G121 Practice for Preparation of Contaminated Test Cou-pons for the Evaluation of Cleaning AgentsG13
7、1 Practice for Cleaning of Materials and Components byUltrasonic TechniquesG136 Practice for Determination of Soluble Residual Con-taminants in Materials by Ultrasonic Extraction3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 contaminant (contamination), nunwanted molecularand
8、 particulate matter that could affect or degrade the perfor-mance of the components upon which they reside.3.1.2 nonvolatile residue (NVR), nmolecular and particu-late matter remaining following the filtration and controlledevaporation of a liquid containing contaminants.3.1.3 DiscussionIn this test
9、 method, the NVR may beuniformly distributed as in a solution or an emulsion, or in theform of droplets. Molecular contaminants account for most ofthe NVR.3.1.4 particle (particulate contaminant), n a piece ofmatter in a solid state with observable length, width, andthickness.3.1.5 DiscussionThe siz
10、e of a particle is usually definedby its greatest dimension and is specified in micrometres.3.1.6 molecular contaminant (non-particulatecontamination), nthe molecular contaminant may be in agaseous, liquid, or solid form.4. Summary of Test Method4.1 A test method is described for the quantitative an
11、alysisof aqueous samples and may be used in the determination ofcontamination on parts, components, and materials used insystems requiring a high degree of cleanliness. The residueremoved during aqueous cleaning or sampling, using cleaningmethods such as Practice G131 and Practice G136, are ana-lyze
12、d using a high-temperature combustion analyzer with asensitivity of 60.2 mgC/L (milligrams of carbon per litre). Anaqueous sample is injected into the sample port. A stream ofoxygen or air carries the sample into the catalytic combustionchamber, which is maintained at a temperature high enough tocom
13、pletely pyrolyze the sample. The sample is combusted inthe catalytic combustion chamber and the products are carriedby the oxygen or air stream into a nondispersive infrared1This test method is under the jurisdiction of ASTM Committee G04 onCompatibility and Sensitivity of Materials in Oxygen Enrich
14、ed Atmospheres and isthe direct responsibility of Subcommittee G04.01 on Test Methods.Current edition approved April 1, 2014. Published April 2014. Originallyapproved in 1996. Last previous edition approved in 2006 as G144 01(2006).DOI: 10.1520/G0144-01R14.2For referenced ASTM standards, visit the A
15、STM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM Inter
16、national, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1(NDIR) detector where the amount of carbon dioxide in the gasstream is determined. Additional information on the use andoperation of carbon analyzers is provided in Test MethodsD2579.4.2 Experience has show
17、n that the bulk of the contaminantsare oils and greases; therefore, the samples will typically beemulsions rather than solutions. Thus, proper handling andpreparation techniques are necessary in order to obtain goodsample homogeneity.5. Significance and Use5.1 It is expected that this test method wi
18、ll be suitable forthe quantitative determination of total carbon in water that hasbeen used to clean, extract, or sample parts, components,materials, or systems requiring a high degree of cleanliness,that is, oxygen systems.6. Apparatus6.1 A total carbon analyzer consists of a high-temperatureTC ana
19、lyzer4that typically utilizes a syringe injection port tointroduce the sample into the analyzer, a furnace containing ahigh-temperature catalytic combustion tube to oxidize carbonto carbon dioxide, a NDIR detector to quantitatively determinethe carbon dioxide, associated tubing to connect the functi
20、onalanalytical modules, and a display and control device. Aminimum sensitivity of 60.2 mgC/L is required.6.1.1 Injection PortProvides a method for the introduc-tion of the sample into the analyzer.6.1.2 High-Temperature FurnaceThe high-temperaturefurnace maintains the combustion tube at a predetermi
21、nedvalue. The combustion tube contains a catalytic bed to oxidizeany organic carbon to carbon dioxide.6.1.3 NDIR DetectorThe nondispersive infrared detectordetermines the quantity of carbon dioxide that is eluted fromthe combustion tube.6.2 SyringeAsampling syringe for injection of the sampleinto th
22、e TC analyzer.6.3 BottleAmber borosilicate for storage of the calibrationsolutions.6.4 Parts PanStainless steel container, typically with avolume between 1 and 4 L, used to contain the parts duringcleaning.7. Reagents7.1 Deionized Water, (reagent water), conforming to Speci-fication D1193, Type II c
23、ontaining less than 0.2 mgC/L. TestMethod D2579 provides detailed instructions if it may becomenecessary to purge dissolved carbon dioxide from the water inorder to achieve this level of carbon in the water.7.2 Carrier Gas, high-purity oxygen, 99.990 %, 1 ppmCO and CO2, 1 ppm total hydrocarbons. Oxy
24、gen of higherpurity may be used if desired. Air that has a hydrocarbon levelless than 1.0 ppm may also be used.7.3 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalyti
25、cal Reagents of the American Chemical Society wheresuch specification are available.5Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.7.3.1 Anhydrous Potassium Hydrogen Phthal
26、ate(KC8H5O4).7.3.2 Concentrated Phosphoric Acid.7.3.3 Concentrated Sulfuric Acid.7.3.4 Concentrated Nitric Acid.7.3.5 Sodium Hydroxide.8. Sample Handling8.1 Sample handling is of critical importance in carbonanalysis to avoid contaminating the sample. Good laboratorytechniques are imperative due to
27、the natural abundance ofcarbon in the environment. The following recommendationsare provided for sample handling during collection,pretreatment, and analysis.8.2 All glassware including syringes, should be treated priorto use to remove traces of residual carbon. Typical treatmentsinclude sodium hydr
28、oxide, hot nitric acid, or hot sulfuric acid.Drain, cool, and rinse with Type II reagent water.8.3 Use a dedicated syringe for each particular carbonrange. When the syringe becomes contaminated, as may beindicated by incomplete wetting of the inner surface, reapplytreatment in accordance with 8.2.9.
29、 Preparation of Standard Solutions9.1 Use Specification D1193, Type II water for the prepa-ration of all standard solutions. The water shall have a TC levelof less than 0.2 mgC/L.9.2 Prepare a standard total carbon stock solution. Weighout 2.126 g of potassium hydrogen phthalate and place into a100-
30、mL volumetric flask. Add 50 to 75 mL of Type II water todissolve the chemical. Add about 0.1 mL of concentratedsulfuric or phosphoric acid to adjust the pH below 3, and fill tothe 100-mL mark with Type II water. This will provide asolution concentration of 10 000 mgC/L. The following for-mula may be
31、 used to calculate the mgC/L:mgC/L 5N 312.01 3 wtMW3104(1)where:mgC/L = milligrams of carbon per litre of solution,N = number of carbon atoms per standard (phthalate)molecule,12.01 = atomic weight of carbon,4Satisfactory equipment is the DC-190 TCAnalyzer from RosemountAnalyticalInc., Dohrmann Divis
32、ion, 3240 Scott Blvd., P.O. Box 58007, Santa Clara, CA95052-8007.5Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemical
33、s, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.G144 01 (2014)2wt = weight of carbon-containing compound, g, andMW = molecular weight of the carbon-containingcompound.Store the stock solutions in amb
34、er borosilicate bottles withPTFE-lined closures at 4C.9.2.1 Replace the solution monthly. Date the solution whenprepared or list the expiration date on the label.9.3 Prepare total carbon working standard solutions fromthe standard stock solution prepared in 9.2, of 1.0 and 5.0mgC/L for expected samp
35、le concentrations less than 5.0mgC/L. If sample concentrations are expected to exceed 5.0mgC/L, a standard solution at least twice the expected concen-tration shall be prepared. It is recommended that 1 Lof solutionbe prepared for total carbon values of 10 mgC/L and below.9.3.1 Store the working cal
36、ibration total carbon standardsolutions at 4C in borosilicate bottles with PTFE-lined clo-sures.9.3.2 Replace the working calibration solutions weekly.Date the solution when prepared or list the expiration date onthe label.10. Preparation of Apparatus10.1 Prepare the TC analyzer for operation in acc
37、ordancewith the manufacturers instructions.NOTE 1It has been found that many manufacturers of this type ofequipment do not specify a high enough temperature to completelypyrolyze the sample to carbon dioxide. Therefore, it is recommended thatthe minimum operating temperature to effect full pyrolysis
38、 be determinedfor the particular instrument selected for this analysis. One indication ofan insufficient combustion temperature is a non-repeatability of values fora calibration solution. Typical temperatures required for the pyrolysis offluorinated hydrocarbons to carbon dioxide in this type of ins
39、trument havebeen found to be in excess of 800C.11. Start-up and Calibration Procedure11.1 Follow the manufacturers instructions for start-up.NOTE 2Many units may be left in a standby mode overnight. In thiscase the start-up procedure is usually greatly simplified and operationsmay be quickly resumed
40、 in the morning.11.2 The TC analyzers may usually be calibrated using aone- or two-point procedure. Follow the manufacturers in-structions for calibration using the working standards preparedin 9.3.11.3 To verify that the instrument is operating properly,perform functional tests using 1.0- and 5.0-m
41、gC/L standards.Aminimum of three injections shall be performed for eachsolution and the results averaged to determine the calibrationvalue.11.3.1 Determine the blank value for the Type II water andclean parts pan used in the cleaning process and record as TCb.The blank value should read 1.0 mgC/L. I
42、f the value exceeds1.0 mgC/L, reclean the parts pan and repeat the blank valuedetermination. If the value again exceeds 1.0 mgC/L, freshreagent water shall be obtained and used for the analysis.11.3.2 The average value for the 1.0- and 5.0-mgC/Lcalibration standards should read 0.851.15 mgC/L and4.8
43、5.2 mgC/L, respectively. If the values for the calibrationstandards do not fall within the specified ranges, discard andprepare new calibration standards. The standard deviationshould not exceed 60.2 mgC/L.12. Procedure12.1 Determine the TC content of samples obtained fromparts that have been extrac
44、ted with Type II water in accordancewith Practice G131 or Practice G136.12.1.1 Agitate the parts pan from which the water samplewill be withdrawn to obtain as homogeneous a solution oremulsion as possible.12.1.2 Draw a sample of water from the sampling pan witha syringe.12.1.3 Inject the sample of w
45、ater into the TC analyzerfollowing the instrument operating instructions and record theTC results.12.1.4 Repeat the analysis two times, and record the resultsfor each injection and the average for the three analyses as TCSin mgC/L.12.2 For samples taken from parts for the purpose ofcleanliness verif
46、ication, an NVR value may be calculated fromthe TC value. In order to calculate the NVR, a sensitivity factor(SF) must be determined. This requires some knowledge of thecomposition of the contaminant. For use of this technique in amanufacturing facility, the problem is easily resolved becausethe man
47、ufacturer knows the identity of the materials used in theprocesses, that is, cutting oils, adhesives, solder flux, and soforth. For an independent cleaning facility, the problem be-comes much more difficult.NOTE 3The contaminant may be a single compound or a mixture ofseveral compounds. The majority
48、 of materials used in processes aremixtures and the actual contaminant should be used to determine SF.12.2.1 To determine the SF based on the mass of a knowncontaminant, disperse 1.0 mg of the contaminant in a 500-mLvolume of water. Perform the carbon analysis 20 times, averagethe results, and recor
49、d as the SFM. The SFMmay be derived bythe following:SFM5 TC/S (2)where:SFM= sensitivity factor (mgC/mg of contaminant),TC = average total carbon value of the sample (mgC/L),andS = contaminant solution concentration (mg/L).Many contaminants are not soluble in water. Heating thewater and ultrasonic agitation may be required to adequatelyemulsify the contaminant.12.2.1.1 Some contaminants are very difficult to emulsifydirectly. Some success has been achieved by applying a knownamount of contaminant to a small, thin, lightweight couponsuch as shim stock. Then th
