ASTM D7359-2008 346 Standard Test Method for Total Fluorine Chlorine and Sulfur in Aromatic Hydrocarbons and Their Mixtures by Oxidative Pyrohydrolytic Combustion followed by Ion .pdf

1、Designation: D 7359 08Standard Test Method forTotal Fluorine, Chlorine and Sulfur in AromaticHydrocarbons and Their Mixtures by OxidativePyrohydrolytic Combustion followed by IonChromatography Detection (Combustion IonChromatography-CIC)1This standard is issued under the fixed designation D 7359; th

2、e number immediately following the 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.

3、Scope1.1 This test method covers the individual determination oftotal fluorine, chlorine and sulfur in aromatic hydrocarbons andtheir mixtures. Samples containing 0.1 to 50 mg/kg of eachelement can be analyzed.1.2 This method can be applied to sample types outside therange of the scope by dilution o

4、f the sample in an appropriatesolvent to bring the total concentrations of fluorine, chlorineand sulfur within the range covered by the test method.However, it is the responsibility of the analyst to verify thesolubility of the sample in the solvent and that the dilutedsample results conform to the

5、precision and accuracy of themethod.1.3 In determining the conformance of the test results usingthis method to applicable specifications, results shall berounded off in accordance with the rounding-off method ofPractice E29.1.4 The values stated in SI units are to be regarded asstandard. No other un

6、its of measurement are included in thisstandard.1.5 This standard does not purport to address 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 reg

7、ulatory limitations prior to use. See Section 8.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 6809 Guide for Quality Control and Quality AssuranceProcedures for Aromatic Hydrocarbons and Related Ma-terialsE29 Practice for Using Significant Digits in Test Data toD

8、etermine Conformance with Specifications2.2 Other Documents:OSHA Regulations 29 CFR paragraphs 1910.1000 and1910.120033. Summary of Test Method3.1 A sample of known weight or volume is placed into asample boat and introduced at a controlled rate into a hightemperature combustion tube. There the samp

9、le is combustedin an oxygen rich pyrohydrolytic environment. The gaseousby-products of the combusted sample are trapped in anabsorption medium where the hydrogen halides (HX) formedduring combustion disassociate into their respective ions, X-while the sulfur oxides (SOX) formed are further oxidized

10、toSO42-in the presence of an oxidizing agent. An aliquot ofknown volume of the adsorbing solution is then automaticallyinjected into an ion chromatograph (IC) by means of a sampleinjection valve. The halide and sulfate anions are separated intoindividual elution bands on the separator column of the

11、IC. Theconductivity of the eluent is reduced with an anion suppressiondevice prior to the ion chromatographs thermal conductivitydetector, where the anions of interest are measured. Quantifi-cation of the fluorine, chlorine and sulfur in the originalcombusted sample is achieved by first calibrating

12、the systemwith a series of standards containing known amounts offluorine, chlorine and sulfur and then analyzing unknownsamples under the same conditions as the standards. Thecombined system of pyrohydrolytic combustion followed by1This test method is under the jurisdiction of ASTM Committee D16 onA

13、romatic Hydrocarbons and Related Chemicals and is the direct responsibility ofSubcommittee D16.04 on Instrumental Analysis.Current edition approved Oct. 15, 2008. Published November 2008.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servicea

14、stm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.1Copyright

15、ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.ion chromatographic detection is referred to as Combustion IonChromatography (CIC).4. Significance and Use4.1 The total fluorine, chlorine and sulfur contained inaromatic hydrocarbon matrices can

16、contribute to emissions, beharmful to many catalytic chemical processes, and lead tocorrosion. This test method can be used to determine totalsulfur and halogens aromatic hydrocarbon matrices, in finishedproducts and can be used for compliance determinations whenacceptable to a regulatory authority

17、using performance basedcriteria.5. Interferences5.1 Substances that co-elute with the anions of interest willinterfere. A high concentration of one anion can interfere withother constituents if their retention times are close enough toaffect the resolution of their peak.6. Apparatus6.1 Autosampler (

18、Optional), capable of accurately deliver-ing 10 to 80 L of sample into the sample boat. Theautosampler may be used as long as the accuracy and perfor-mance of the method is not degraded.NOTE 1Multiple rinsing with clean solvent between sample injectionsand/or sampling between different sample vials

19、to minimize carryovercontamination from previous samples is recommended. A solvent flushfrom a vial separate from the solvent wash, providing clean, uncontami-nated solvent may also be used. These features may be used as long asthey do not degrade the performance and accuracy of the method.6.2 Balan

20、ce, analytical, with sensitivity to 0.0001 g.6.3 Boat Inlet SystemThe system provides a samplingport for the introduction of liquid and solid samples into thesample boat and is connected to the inlet of the PyrohydrolyticCombustion Tube. The system is swept by a humidified inertcarrier gas and shall

21、 be capable of allowing the quantitativedelivery of the material to be analyzed into the pyrohydrolyticoxidation zone at a controlled and repeatable rate.6.4 Boat Inlet Cooler (Optional)Sample volatility andinjection volume may require an apparatus capable of coolingthe sample boat prior to sample i

22、ntroduction. Thermoelectriccoolers (peltier) or recirculating refrigerated liquid devices arestrongly recommended. Switching sample boats between eachanalysis may prove effective, provided sample size is not toolarge.6.5 Flow ControlThe apparatus must be equipped withflow controllers capable of main

23、taining a constant supply andflow of oxygen and argon gas.6.6 Furnace which can maintain a minimum temperature of900C.6.7 Gas Adsorption Unit, having an adsorption tube ofeither 10 or 20 mL which is automatically filled with a knownvolume of absorption solution by a built-in burette or othersimilar

24、device. The GasAdsorption Unit is interfaced to the IonChromatograph and injects an aliquot of the adsorption solu-tion into the Ion Chromatograph after the sample is combustedand the by-products of combustion are absorbed. The GasAdsorption Unit rinses out the gas lines with Type I reagentwater (7.

25、2) from the pyrohydrolytic combustion tube after thecompletion of the sample combustion to ensure all the com-bustion by-products (HX and SO2) are absorbed. The GasAdsorption Unit rinses the gas lines and adsorption tube withType I reagent water (7.2) prior to sample combustion and afterthe absorpti

26、on solution is injected into the Ion Chromatographto minimize cross contamination from the previous analysis.6.8 Gas-Tight Sampling Syringe, capable of accurately de-livering 10 to 80 L of standard or sample.6.9 Pyrohydrolytic Combustion Tube made of quartz andconstructed such that when the sample i

27、s combusted in thepresence of humidified oxygen, the by-products of combustionare swept into the humidified pyrohydrolytic combustion zone.The inlet end shall allow for the stepwise introduction andadvancement of a sample boat into the heated zone and shallhave a side arm for the introduction of the

28、 humidified carriergas and oxygen. The pyrohydrolytic combustion tube must beof ample volume, and have a heated zone with quartz wool orother suitable medium providing sufficient surface area so thatthe complete pyrohydrolytic combustion of the sample isensured.6.10 Humidifier Delivery System, capab

29、le of deliveringType 1 reagent water (7.2) to the combustion tube at acontrolled rate sufficient to provide a pyrohydrolytic environ-ment.6.11 Ion Chromatograph (IC)4, equipped with:6.11.1 High Performance inert PEEK-(polyetheretherketone) flow path system is required.6.11.2 High Pressure eluent pum

30、p, capable of delivering0.0 to 5 mL/min (without eluent generator; 0.1 to 3 mL/min(with eluent generator), in 0.01 mL/min increments. Flow rateaccuracy of 290Equivalents/column with alkanol quartenary ammoniumfunctional groups.6.11.6 Guard Column AG11HC (4X50mm) or equivalent,packed with same materi

31、al for protection of the anion separatorcolumn and constructed of PEEK.6.11.7 Post-Column Chemical Suppression Device, capableof reducing the absolute conductivity of eluent concentrationsof up to 200 mM KOH (or NaOH). Delivery of hydronium ionsfor suppression by electrolysis of recycled eluent thro

32、ugh acation exchange membrane.4Many different companies manufacture automatic ion chromatographs. Consultthe manufacturer for details in setup and operation. Other systems may be used aslong as precision is shown to be as good as or better than the precision in themethod.D73590826.11.8 Eluent Genera

33、tor (Optional), an eluent generatorcapable of producing eluents of 10 to 100 mM KOH withcontinuous eluent purification can be employed.6.11.9 Data Acquisition System, such as an integrator orcomputer data handling system capable of integrating the peakareas of ion chromatograph.6.12 Quartz or Cerami

34、c Sample Boats of sufficient size tohold 10 to 80 L or mg of sample.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents shall conform to the specification of the Committeeon Analytical Reagents

35、of the American Chemical Society,where such specifications are available.5Other grades may beused, provided that the reagent is of sufficiently high purity topermit its use without lessening the accuracy of the determi-nation.7.2 Purity of WaterUnless otherwise indicated, referencesto water shall be

36、 understood to mean Type 1 conforming toSpecification D 1193.7.3 Quartz Wool, (fine grade) or other suitable medium.7.4 Argon, carrier gas minimum 99.9 % purity.NOTE 2Purification scrubbers to ensure the removal of containmentsare recommended such as moisture (molecular sieve) and hydrocarbontrap fi

37、lters (activated charcoal or equivalent) are recommended.7.5 Oxygen, combustion gas minimum 99.6 % purity.7.6 Gas Regulators, two-stage, gas regulators capable ofregulating the pressures to 40 to 60 psi must be used for thecarrier and combustion gases.7.7 Calibration Standards, certified calibration

38、 standardsfrom commercial sources or calibration standards prepared inthe laboratory containing the elements of interest at theconcentrations of interest.NOTE 3Other calibration standard sources and diluents may be usedif precision and accuracy are not degraded.NOTE 4Calibration standards are typica

39、lly re-mixed and re-certifiedon a regular basis depending upon frequency of use and age. Calibrationstandards can have a useful life of about 6 to 12 months if properly storedin a cool, dark place.NOTE 5A correction for chemical impurity can be used if deemednecessary.7.8 Dibenzothiophene, FW 184.26

40、, 17.399 % S.7.9 Flurobenzoic Acid, FW 96.10, 13.56 % F.7.10 2,4,5 Trichlorophenol, FW 197.46, 53.87 % Cl.7.11 Hydrogen Peroxide 30 %, FW 34.01 H2O2(see Section8 regarding Hazards).7.12 Potassium Hydroxide, for eluent preparation (see Sec-tion 8 regarding Hazards).7.13 Toluene, Xylene, Isooctane or

41、Methanol, Reagentgrade. (Other solvents similar to those occurring in samples tobe analyzed are also acceptable.) Correction for contaminatelevels of elements of interest must be corrected for (solventblank). Alternatively, using a solvent with non-detectablecontamination relative to the sample make

42、s the blank correc-tion unnecessary.7.14 Volumetric Flasks-Type Class A, at the volume speci-fied to use in this method to prepare standards, reagents andsolutions.7.15 Stock Standard Solutions of approximately-1000 ug/mLPrepare a stock standard solution by accurately weighingto within 10 % of the t

43、arget weights for any or all of the targetstandard compound(s) listed in 7.15.1, 7.15.2, and 7.15.3 intoa 100 mL class A volumetric flask. Dilute to volume with theselected solvent described in 7.13. Calculate the actual con-centration of the stock standard solution(s) for each element byusing the e

44、quation below with the actual recorded weight of thetarget compound used for each element. This stock standardsolution can be further diluted to other desired concentrations.Other suitable materials, weights and volumes may be substi-tuted in preparing stock calibration standards as long as theperfo

45、rmance of the method is not degraded.Target Standard Compound(s)7.15.1 Flurobenzoic Acid, (Fluorine), 0.7375 g targetweight.7.15.2 2,4,5 Trichlorophenol, (Chlorine), 0.1856 g targetweight.7.15.3 Dibenzothiophene, (Sulfur), 0.5748 g target weight.Calculation FormulaStock Standard Solution g/ml! 5 A!

46、B! 106! / C! K! (1)where:A = weight of the target compound actually weighed ingrams, g,B = % concentration of the elements in the respective targetcompounds listed in 7.8, 7.9, and 7.10,C = final diluted volume, mL, andK = 100 (factor correction for %).7.16 Phosphate Stock Solution (1.00 mL = 1.00 m

47、gPhosphate)Weigh to within 10 % 1.433 g of potassiumdihydrogen phosphate (KH2PO4) in water and dilute to 1 Lwith water in a class A volumetric flask and mix well.7.17 Absorbing SolutionDilute the Phosphate Stock So-lution with water in a class A volumetric flask to a finalconcentration of approximat

48、ely 1.00 ppm. The concentration ofphosphate in the absorbing solutions is used as an internalstandard by the Ion Chromatograph.8. Hazards8.1 Consult the current version of OSHA regulations, sup-pliers Material Safety Data Sheets, and local regulations for allmaterials used in this test method.8.2 Hi

49、gh temperature and flammable hydrocarbons occur inthe test method. Use materials that are rated for containingthese hydrocarbons in all sample containers and sample trans-fer apparatus. Exercise extra care when using flammablematerials near the oxidative furnace.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 LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopei