1、Designation: D7319 12D7319 13Standard Test Method forDetermination of Existent and Potential Sulfate andInorganic Chloride in Fuel Ethanol and Butanol by DirectInjection Suppressed Ion Chromatography1This standard is issued under the fixed designation D7319; the number immediately following the desi
2、gnation 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. Scope*1.1 This test method covers a dir
3、ect injection ion chromatographic procedure for determining existent and potential inorganicsulfate and total inorganic chloride content in hydrous and anhydrous denatured ethanol and butanol to be used in motor fuelapplications. It is intended for the analysis of ethanol and butanol samples contain
4、ing between 1.020 1.0 to 20 mg/kg of existentor potential inorganic sulfate and 1.050 1.0 to 50 mg/kg of inorganic chloride.NOTE 1Tertiary butanol is not included in this test method. 1-butanol, 2-butanol, and isobutanol are included in the testing and research report forthis test method.1.2 The val
5、ues stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 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
6、safety and health practices and determine the applicability of regulatorylimitations prior to use. Material Safety Data Sheets are available for reagents and materials. Review them for hazards prior tousage.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD4052 Test Me
7、thod for Density, Relative Density, and API Gravity of Liquids by Digital Density MeterD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD5827 Test Method for Analysis of Engine Coolant for Chloride and Othe
8、r Anions by Ion ChromatographyD6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-ment System PerformanceD6792 Practice for Quality System in Petroleum Products and Lubricants Testing LaboratoriesD7318 Test Method for Existent Inor
9、ganic Sulfate in Ethanol by Potentiometric TitrationD7328 Test Method for Determination of Existent and Potential Inorganic Sulfate and Total Inorganic Chloride in Fuel Ethanolby Ion Chromatography Using Aqueous Sample Injection2.2 European Norm Standards:3EN 15492 Ethanol as a blending component fo
10、r petrol - Determination of inorganic chloride and sulfate content - Ionchromatographic method3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 existent inorganic sulfate, ninorganic sulfate species actually present in the sample at the time of analysis with nooxidation treatmen
11、t.1 This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products and Lubricants and is the direct responsibility of Subcommittee D02.03 onElemental Analysis.Current edition approved Dec. 1, 2012May 1, 2013. Published December 2012August 2013. Originally approved in 2007. La
12、st previous edition approved in 20112012as D7319D7319 12.111. DOI: 10.1520/D7319-12.10.1520/D7319-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Do
13、cument Summary page on the ASTM website.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes ha
14、ve 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 appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official do
15、cument.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.2 inorganic chloride, nchloride present as hydrochloric acid, ionic salts of this acid, or mixtures of these.3
16、.1.3 inorganic sulfate, nsulfate (SO4-2) species present as sulfuric acid, ionic salts of this acid, or mixtures of these.3.1.4 potential sulfate, ninorganic sulfate species present after the sample has been reacted with an oxidizing agent.4. Summary of Test Method4.1 For existent inorganic sulfate
17、and total chloride, a small volume of an ethanol or butanol sample is directly injected into asuitably configured ion chromatograph in accordance with manufacturers recommendations for this test method. For potentialsulfate, 0.5 mL of 30?%30 % hydrogen peroxide solution is added to 9.5 mL of the eth
18、anol or butanol sample, and then injectedinto the ion chromatograph. Ions are separated based on their affinity for exchange sites of the resin with respect to the resinsaffinity for the eluent.The suppressor increases the sensitivity of the test method by both increasing the conductivity of the ana
19、lytesand decreasing the conductivity of the eluent. It also converts the eluent and analytes to the corresponding hydrogen forms ofanions. Anions are quantified by integration of their responses compared with an external calibration curve, and are measured asmilligrams/litre, then converted to milli
20、grams/kilograms. The calibration standards are prepared in an aqueous matrix.4.1.1 The use of acid suppression technology is more significant for the precision of sulfate measurement than for chloride.Sulfate precision will be worse if acid suppression is not used.4.2 Similar methods for chloride an
21、d sulfate determinations can be found in EN 15492 for total chloride, in Test Method D7328for total chloride and existent and potential inorganic sulfate by ion chromatography with aqueous sample injection, and in TestMethod D7318 for existent inorganic sulfate by potentiometric lead titration and T
22、est Method D5827 for chloride and other anionsin engine coolants by ion chromatography.NOTE 2Butanol has limited solubility in water, do not dilute samples with water prior to analysis. In addition, any remnant water from the sampledelivery device or glassware may lead to low recoveries of sulfate a
23、nd chloride. Avoid unintended water contamination of the sample. Added water canlead to phase separation of the sample. The chloride and sulfate ions can migrate to the water dominate phase and lower the recovery from the butanol.5. Significance and Use5.1 Sulfates and chlorides can be found in filt
24、er plugging deposits and fuel injector deposits. The acceptability for use of thefuel components and the finished fuels depends on the sulfate and chloride content.5.2 Existent and potential inorganic sulfate and total chloride content, as measured by this test method, can be used as onemeasure of t
25、he acceptability of gasoline components for automotive spark-ignition engine fuel use.6. Interferences6.1 Interferences can be caused by substances with similar ion chromatographic retention times, especially if they are in highconcentration compared to the analyte of interest. Sample dilution can b
26、e used to minimize or resolve most interference problems.6.2 A water dip (system void, negative peak as shown in Fig. 1) can cause interference with some integrators. Usually, forchloride and sulfate determinations, the water dip should not be a problem since the chloride and sulfate peaks are far a
27、way fromthe water dip.6.3 Given the trace amounts of chloride and sulfate determined in this test method, interferences can be caused by contaminationof glassware, eluent, reagents, and the like. For example, sodium leaching from glassware can precipitate with sulfate giving lowsulfate results. Take
28、 care to ensure that contamination is kept at the lowest possible levels. The use of powder-free gloves is highlyrecommended to prevent sample contamination.7. Apparatus7.1 Analytical Balance, capable of weighing up to 100 g accurately to 0.0001 g.7.2 Drying Oven, controlled at 110 6 5C for drying s
29、odium sulfate and sodium chloride.7.3 Desiccator, containing freshly activated silica gel (or equivalent desiccant) with moisture content indicator.7.4 Pipets or Volumetric Transferring Devices, appropriately sized Class A glass pipets or their equivalent or variable volumeautomatic pipets fitted wi
30、th disposable polypropylene tips.7.5 Volumetric Flasks (with Glass Stoppers), Class A of 10, 25, 50, 100, 1000, 2000cc capacity.7.5.1 Container, equipped with a closure to prevent ethanol evaporation, 1 L (for sample collection). See 6.3 for additionalinformation.7.6 Ion Chromatograph, analytical sy
31、stem with all required accessories including syringes, columns, suppressor, anddetector.detector which can be demonstrated to obtain the precision and detection limits and requirements of the method.7.6.1 Injection System, capable of delivering 20 L with a precision better than 1?%,1 %, or as recomm
32、ended for thisdetermination by the manufacturer.7.6.2 Pumping System, capable of delivering mobile phase flows between 0.2 and 2.5 mL/min with a precision better than2%,2 %, or as recommended for this determination by the manufacturer.D7319 1327.6.3 Guard Column, for protection of the analytical col
33、umn from strongly retained constituents. Better separations are obtainedwith additional theoretical plates.7.6.4 Anion Separator Column, 100?%100 % solvent compatible and capable of producing satisfactory analyte (sulfate andchloride) separation (Fig. 1).7.6.5 Anion Suppressor Device, vendor specifi
34、c and capable of using acid suppression technology.7.6.5.1 Tri-Chamber Approach, 100?%100 % solvent compatible tri-chamber micro packed bed with cation exchange resin (orequivalent). Suppressor device should simultaneously be on-line continuously chemically regenerated to its hydrogen form usingany
35、mineral acid providing H+ ion.7.6.5.2 Continuous Approach, The regenerant channels are flushed with a mineral acid (sulfuric) to supply hydronium ionsrequired for the suppression reaction. The solvent ?compatiblecompatible ion exchange membranes provide the transport pathwayfor the hydronium ions in
36、to the eluent channel and the transport of sodium and other cations out of the eluent channel.7.6.6 Conductivity Detector, (low volume), temperature controlled to 0.01C, capable of at least 0 to 1000 S/cm on a linearscale.7.6.7 Integrator or Chromatography Data System Software, capable of measuring
37、peak areas and retention times, and correctingthe data in accordance with the baseline of the chromatogram.7.7 Gloves, powder-free examination type.8. Reagents8.1 Purity of ReagentsReagent grade or higher purity chemicals shall be used for the preparation of all samples, standards,eluent, and regene
38、rator solutions. Unless otherwise indicated, it is intended that all reagents conform to the specifications of theCommittee onAnalytical Reagents of theAmerican Chemical Society, where such specifications are available.4 Other grades maybe used, provided it is first ascertained that the reagent is o
39、f sufficiently high purity to permit its use without lessening the accuracyof the determination.8.2 Purity of WaterUnless otherwise indicated, reference to water shall be understood to mean reagent water as defined byType II or better in Specification D1193. For eluent preparation and handling, comp
40、ly with all ion chromatograph instrument andcolumn vendor requirements (for example, filtering, degassing, and the like).4 Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed bythe American Chem
41、ical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and NationalFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.NOTE 1Chromatogram retention times may be different depending on instruments or columns used
42、.FIG. 1 Typical Ion Chromatogram of a Solution Containing 1 mg/L of Various Anions in WaterD7319 1338.3 Eluent Buffer Stock SolutionSodium bicarbonate (NaHCO3) 1.0 mM and sodium carbonate (Na2CO3) 3.2 mM. Dissolve8.4 6 0.0005 g of NaHCO3 and 33.92 6 0.0005 g of Na2CO3 in reagent water in a 1-L Type
43、A volumetric flask and dilute tovolume. Dilute 10.0 mL of this stock solution to 1 L in a 1-L Type A volumetric flask with degassed reagent water. The eluentsolution used may be different if other system or analytical columns are used.NOTE 3Other volumes of stock solution can be prepared using appro
44、priate ratios of reagents. Follow the specific guidelines for this solution fromthe vendor of the column being used. Alternatively, this solution can be purchased from a qualified vendor.8.4 Suppressor Regenerant Solution for Suppressor0.1 M sulfuric acid. Carefully add 334 mL of reagent grade sulfu
45、ric acid(relative density 1.84) to approximately 500 mL reagent water in a 1-L volumetric flask. (WarningThis will generate a very hotsolution. Allow it to cool before diluting to 1000 mL volume. Never add water to concentrated acid.) Dilute to 1000 mL withreagent water, and label this solution as 1
46、0.0 M sulfuric acid. Dilute 10.0 mL of this concentrate to 1000 mL with reagent waterfor the final 0.1 M working suppressor solution.The regenerate solution used may be different if other system or analytical columnsare used.NOTE 4Other volumes of this solution can be prepared using appropriate rati
47、os of reagents. Follow the specific guidelines for this solution from thevendor of the suppressor being used.8.5 Sodium Sulfateanhydrous, reagent grade, 99?%99 % minimum purity. (WarningDo not ingest. Avoid unnecessaryexposure.)8.6 Sodium ChlorideACS or reagent grade, 99?%99 % minimum purity.8.7 Tet
48、rabutylamonium BisulfateTechnical or reagent grade, 99 % minimum purity.8.8 Tetrabutylammonium ChlorideTechnical or reagent grade 97 % minimum purity.8.9 ButanolACS, 99 % minimum purity. Could consist of isobutanol, sec butanol, or n-butanol. (WarningFlammable,toxic, and may be harmful if ingested o
49、r inhaled. Affects central nervous system similar to excessive alcohol exposure.)8.10 Ethanoldenatured with methanol, formula 3A or histological grade ethanol, anhydrous, denatured with ethyl acetate,methylisobutyl ketone and hydrocarbon naphtha. (WarningFlammable, toxic, and may be harmful or fatal if ingested or inhaled.Avoid skin contact.)8.11 Hydrogen PeroxideACS reagent grade, 30 wt % in water.8.12 Hydrogen Peroxide Solution, 30?%30 %commercially available 30?%30 % hydrogen peroxide solution.9. Preparation of Standard Solutions9.1 Stock
