1、Designation: G 144 01 (Reapproved 2006)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 G 144; the number immediately following the desig
2、nation 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the de
3、termination of residualcontamination in an aqueous sample by the use of a totalcarbon (TC) analyzer. When used in conjunction with PracticeG 131 and G 136, this procedure may be used to determine thecleanliness of systems, components, and materials requiring ahigh level of cleanliness, such as oxyge
4、n systems. 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 ad
5、dress 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:2D 1193 Speci
6、fication for Reagent WaterD 2579 Test Method for Total Organic Carbon in Water3F 331 Test Method for Nonvolatile Residue of SolventExtract from Aerospace Components (Using Flash Evapo-rator)G 121 Practice for Preparation of Contaminated Test Cou-pons for the Evaluation of Cleaning AgentsG 131 Practi
7、ce for Cleaning of Materials and Componentsby Ultrasonic TechniquesG 136 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 partic
8、ulate 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 method
9、, 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), na piece of mat-ter in a solid state with observable length, width, and thickness.3.1.5 DiscussionThe size of
10、a particle is usually definedby its greatest dimension and is specified in micrometres.3.1.6 molecular contaminant (non-particulate contamina-tion), nthe molecular contaminant may be in a gaseous,liquid, or solid form.4. Summary of Test Method4.1 A test method is described for the quantitative analy
11、sisof 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 G 131 and Practice G 136, areanalyzed u
12、sing 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 tocomple
13、tely pyrolyze the sample. The sample is combusted in1This test method is under the jurisdiction of ASTM Committee G04 onCompatibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and isthe direct responsibility of Subcommittee G04.01 on Test Methods.Current edition approved Oct. 1, 20
14、06. Published December 2006. Originallyapproved in 1996. Last previous edition approved in 2001 as G 144 01.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the stan
15、dards Document Summary page onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.the catalytic combustion chamber and the products are carriedby the oxygen or air stream into a nondispersive infrared(NDIR) de
16、tector where the amount of carbon dioxide in the gasstream is determined. Additional information on the use andoperation of carbon analyzers is provided in Test MethodsD 2579.4.2 Experience has shown that the bulk of the contaminantsare oils and greases; therefore, the samples will typically beemuls
17、ions 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 will be suitable forthe quantitative determination of total carbon in water that hasbeen used to clean,
18、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 analyzer4that typically utilizes a syringe injection port tointroduce the sample into the analyzer, a fur
19、nace containing ahigh-temperature catalytic combustion tube to oxidize carbonto carbon dioxide, a NDIR detector to quantitatively determinethe carbon dioxide, associated tubing to connect the functionalanalytical modules, and a display and control device. Aminimum sensitivity of 60.2 mgC/L is requir
20、ed.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 predeterminedvalue. The combustion tube contains a catalytic bed to oxidizeany organic carbon to carbon dioxide.
21、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 the TC analyzer.6.3 BottleAmber borosilicate for storage of the calibra-tion solutions.6.4 Parts PanStai
22、nless 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 D 1193, Type II containing less than 0.2 mgC/L. TestMethod D 2579 provides detailed instructions if it may becomenec
23、essary 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. Oxygen of higherpurity may be used if desired. Air that has a hydrocarbon levelless than 1.0 ppm may
24、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 onAnalytical Reagents of the American Chemical Society wheresuch specification are available.5Other grades
25、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 Phthalate(KC8H5O4).7.3.2 Concentrated Phosphoric Acid.7.3.3 Concentrated Sulfuric Acid.7.3.4 Concentrate
26、d 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 the natural abundance ofcarbon in the environment. The following recommendationsare provided for s
27、ample handling during collection, pretreat-ment, and analysis.8.2 All glassware including syringes, should be treated priorto use to remove traces of residual carbon. Typical treatmentsinclude sodium hydroxide, hot nitric acid, or hot sulfuric acid.Drain, cool, and rinse with Type II reagent water.8
28、.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. Preparation of Standard Solutions9.1 Use Specification D 1193, Type II water for the prepa-rati
29、on 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-mL volumetric flask. Add 50 to 75 mL of Type II water todissolve the chemical. Add about 0.1 mL
30、 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 used to calculate the mgC/L:mgC/L 5N 3 12.01 3 wtMW3 104(1)where:mgC/L = milligrams of carbon
31、per litre of solution,N = number of carbon atoms per standard (phthalate)molecule,4Satisfactory equipment is the DC-190 TCAnalyzer from RosemountAnalyticalInc., Dohrmann Division, 3240 Scott Blvd., P.O. Box 58007, Santa Clara, CA95052-8007.5Reagent Chemicals, American Chemical Society Specifications
32、 , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, In
33、c. (USPC), Rockville,MD.G 144 01 (2006)212.01 = atomic weight of carbon,wt = weight of carbon-containing compound, g, andMW = molecular weight of the carbon-containing com-pound.Store the stock solutions in amber borosilicate bottles withPTFE-lined closures at 4C.9.2.1 Replace the solution monthly.
34、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 sample concentrations less than 5.0mgC/L. If sample concentrations are expected to exceed 5.0m
35、gC/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 calibration total carbon standardsolutions at 4C in borosilicate bottles with PTFE-lined clo-
36、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 accordancewith the manufacturers instructions.NOTE 1It has been found that many manufacturers
37、 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 be determinedfor the particular instrument selected for this analysis. One indication ofa
38、n 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 instrument havebeen found to be in excess of 800C.11. Start-up and Calibration Procedure11.1
39、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 in the morning.11.2 The TC analyzers may usually be calibrated using aone- or two-point p
40、rocedure. 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-mgC/L standards.Aminimum of three injections shall be performed for eachsolution and the re
41、sults 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. If the value exceeds1.0 mgC/L, reclean the parts pan and repeat the blank valuedeterminatio
42、n. 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 and4.85.2 mgC/L, respectively. If the values for the calibrationstandards do not fall within the
43、 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 extracted with Type II water in accordancewith Practice G 131 or Practice G 136.12.1.1 Agitate t
44、he 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 water into the TC analyzerfollowing the instrument operating instructions and record theT
45、C 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 verification, an NVR value may be calculated fromthe TC value. In order to calculate the NVR,
46、 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 manufacturer knows the identity of the materials used in theprocesses, that is, cutting oil
47、s, 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 of materials used in processes aremixtures and the actual contaminant should be used to
48、 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 record as the SFM. The SFMmay be derived bythe following:SFM5 TC/S (2)where:SFM= sensitivity
49、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 the coupon is ultrasonically agitatedin a known amount of heated water. The coupon is dried
