1、Designation: D1318 00 (Reapproved 2011)D1318 16Standard Test Method forSodium in Residual Fuel Oil (Flame Photometric Method)1This standard is issued under the fixed designation D1318; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision
2、, 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 Scope*1.1 This test method covers the determination of sodium in residual fuel oil by means of a flame phot
3、ometer. Its precision inlow ranges limits its application to samples containing more than 1515 mg mg/kg kg sodium. Other elements commonly foundin residual fuel oil do not interfere.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this s
4、tandard.1.3 This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of theuser of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitationsprior to use. For specific haza
5、rd statements see 6.3, 6.5, 6.7, 8.2, 6.8, 6.9, and Note 3.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD6299 Practice for
6、 Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-ment System Performance3. Summary of Test Method3.1 Aweighed sample is reduced to a carbonaceous ash under controlled conditions. The residual carbon is removed by heatingin a muffle furnace at 550
7、C.550 C. The ash is dissolved, diluted to volume, and the sodium determined by means of a flamephotometer.4. Significance and Use4.1 Excessive amounts of sodium can indicate the presence of materials that cause high wear of burner pumps and valves, andcontribute to deposits of boiler heating surface
8、s.5. Apparatus5.1 Flame Photometer, capable of isolating the sodium doublet at 589 nm 589 nm and stable enough to give repeatablemeasurements that do not vary more than 5 % of their mean in the 22 mgkg to 2020 mg mg/kg kg range of sodium.5.2 Platinum Dish, 100-mL100 mL capacity, approximately 35 mm
9、35 mm in depth.5.3 Electric Muffle Furnace, capable of operating over a variable range from 200200 C to 600C600 C and of maintaining atemperature of 550550 C 6 50C.50 C.6. Reagents and Materials6.1 Purity of ReagentsReagent grade chemicals shall be used in all tests. Unless otherwise indicated, it i
10、s intended that allreagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where1 This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products Products, Liquid Fuels, and Lubricantsand is the direct responsibili
11、ty ofSubcommittee D02.03 on Elemental Analysis.Current edition approved May 1, 2011July 1, 2016. Published May 2011July 2016. Originally approved in 1954. Last previous edition approved in 20052011 as D1318 00(2005).(2011). DOI: 10.1520/D1318-00R11.10.1520/D1318-16.2 For referencedASTM standards, vi
12、sit theASTM 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.This document is not an ASTM standard and is intended only to provide the user of an ASTM stand
13、ard 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 appropriate. In all cases only the current versionof the standard as published by ASTM
14、 is to be considered the official document.*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 States1such specifications are available.3 Other grades can be used, provided it is f
15、irst ascertained that the reagent is of sufficiently highpurity to permit its use without lessening the accuracy of the determination.6.2 Purity of WaterUnless otherwise indicated, references to water shall be understood to mean reagent water as defined byType II or III of Specification D1193.6.3 Hy
16、drochloric Acid (sp gr 1.19)Concentrated hydrochloric acid (HCl). (WarningWarningPoison. Causes severeburns. Harmful or fatal if swallowed or inhaled.)6.4 Hydrochloric Acid (1+9)Mix 1 volume of HCl (sp gr 1.19) with 9 volumes of water.6.5 Hydrofluoric Acid (48 %)Concentrated hydrofluoric acid (HF).
17、(WarningWarningPoison. Causes severe burns.Harmful or fatal if swallowed or inhaled.)6.6 Sodium Solution, Standard (1000 mg Na/L)Dissolve 3.0883.088 g 6 0.005 g 0.005 g of dried sodium sulfate (Na2SO4)in water and dilute to 1 L 1 L in a volumetric flask. Store in a polyethylene bottle.6.7 Sulfuric A
18、cid (1+1)Carefully add, while stirring, 1 volume of concentrated sulfuric acid (H2SO4, sp gr 1.84) to 1 volumeof water. (WarningWarningPoison. Causes severe burns. Harmful or fatal if swallowed or inhaled.)6.8 Ethyl Alcohol, C2H6O, 95 % reagent grade. (WarningFlammable.)6.9 2-Propanol, C3H8O, 99 % r
19、eagent grade (WarningFlammable.)7. Sampling7.1 Sampling shall be done in accordance with Practices D4057 or Test Method D4177.7.2 Use a clear, clean glass pint bottle, previously rinsed twice with HCl (1+9) and once with water and allowed to dry, forsampling the bulk material or plant streams. Obtai
20、n a representative sample but do not fill the bottle more than about two-thirdsfull. Warm viscous samples until they can be mixed readily. Stir up any material that has settled out and shake the sample for 3min 3 min just prior to weighing it out.7.3 Optimum sample size for most instruments is that
21、which contains from 0.50.5 mg to 1.0 mg 1.0 mg of sodium. Estimatethe sample size as follows (see Note 1):Sample size,g5750/estimated sodium content,mg/kg (1)NOTE 1An estimate of the maximum amount of sodium in a sample can be obtained from its ash value. For example, an ash of 0.01 % wouldundoubted
22、ly have less than 0.005 % sodium (50 ppm). (50 ppm). If there is no estimate as to the probable sodium range in a sample, it is more expedientto weigh out a large amount, for example 60 g, because the test method provides for dilution of sample solutions that are more concentrated than thestandards.
23、8. Calibration8.1 Dilute the sodium solution (1000 mg(1000 mg Na Na/L) L) so as to obtain solutions containing 2,2 mg 4,L, 4 mg 6,L,6 mg 8,L, 8 mg 10,L, 10 mg 12,L, 12 mg 15,L, 15 mg 18,L, 18 mgL, and 2020 mg mg/L L (approximately equivalent tomg/kg). Store all dilute sodium solutions in polyethylen
24、e bottles.8.2 Prepare the flame photometer for use as described in the manufacturers instruction manual. Carefully adjust the pressureof the gases (WarningWarningDangerous.) used for flame combustion in the order described by the manufacturer untiloptimum control is achieved. Select a standard appro
25、ximately in the middle of the optimum range of the instrument being used.While atomizing this medium-range standard, adjust the wavelength selector to the greatest response for the sodium doublet atabout 589 nm 589 nm and adjust all controls of the instrument to optimum performance. Finally, adjust
26、the sensitivity control togive a proper scale reading.8.3 Atomize each of the standard solutions and record the scale response for each. Run repeat checks on the medium-rangestandard selected in 6.2 after each of these standards to determine whether the flame photometer is functioning properly. Make
27、 theindicated adjustments, if required, and rerun the standards.8.4 Prepare a working curve by plotting the milligrams of sodium per litre against the scale readings.9. Procedure9.1 Preparation of Sample:9.1.1 Weigh into a thoroughly clean, dry 100-mL100 mL platinum dish the appropriate size sample
28、(7.3) with an accuracy ofat least 1 part per 100 parts of sample (Note 2). Samples larger than 75 g 75 g require a second filling of the platinum dish; forsuch samples, obtain the sample weight from the difference between the initial and final weights of the sample bottle. Place the3 Reagent Chemica
29、ls, American Chemical Society Specifications, American Chemical Society, Washington, DC. For suggestions on the testing of reagents not listed bythe American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and Nationa
30、lFormulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.D1318 162platinum dish containing the fuel oil on a silica triangle properly supported, and heat with a bunsen burner until the contents igniteand burn readily (Note 3). Continue heating with the burner in such a manner that the s
31、ample burns at a uniform and moderaterate and only ash and carbon remain after burning ceases. For samples larger than 75 g, 75 g, cool the dish and fill it approximatelytwo-thirds full with additional well-shaken sample, and burn as above.NOTE 2Handle the platinum dish only with platinum-tip tongs
32、and do not touch it with the fingers during the test. Carefully dust the bottom of thedish with a clean camel-hair brush before each weighing.NOTE 3If sample contains an appreciable amount of water, as indicated by spattering when heated, add a few millilitres of ethyl-alcohol (95 %)(WarningWarningF
33、lammable) or isopropyl alcohol (99 %) (WarningWarningFlammable) before heating. Include the alcohol in the blankdetermination.9.1.2 Place the dish in a muffle furnace at no more than 200C200 C (Note 3). Slowly raise the temperature to 550550 C 650C.50 C. Leave the muffle door slightly ajar until onl
34、y a little carbon remains in the dish; then close the door and continue theignition until no carbon is visible.NOTE 4The platinum dishes should be placed on silica plates or silica triangles on the floor of the muffle furnace. Particular care must be exercisedto avoid contamination of the sample wit
35、h particles from the roof, walls, and the door of the furnace. During the initial ignition, the opening of the muffledoor must be carefully adjusted so that the air flow into the muffle is not excessive. Too great an air flow causes high temperatures in the burning carbonand also possible loss of as
36、h from the dish.9.1.3 Cool the dish to room temperature, add 1 mL1 mLof H2SO4 (1+1) and about 1 mL1 mLof HF to the platinum dish (Note5), evaporate to dryness under a hood, and replace the dish in the muffle furnace at 550550 C 6 50C50 C for 15 min.15 min.NOTE 5Unless the silica is removed, low valu
37、es will result from the occlusion of sodium in the insoluble residue.9.1.4 Cool the platinum dish, wash down its sides with about 10 mL 10 mL of water and, by means of a dropper, add 2 dropsof H2SO4 (1+1). Heat the dish on a steam bath, to effect the solution of the sodium salts, until approximately
38、 1 mL 1 mL of liquidremains. Remove from the steam bath, add 55 mL to 10 mL 10 mL of water, and filter the solution through an acid-washed filterpaper or an acid-washed, sintered-glass filter into a 100-mL100 mLvolumetric flask. Wash the dish and filter with water, collectingthe wash water in the vo
39、lumetric flask. Dilute to 100 mL 100 mL with water and mix. If the ashed sample is known to containless than 0.5 mg 0.5 mg of sodium, make a proportionately smaller dilution to obtain 55 mg to 10 mg 10 mg of sodium per litrein the final solution.9.2 Photometric Measurement:9.2.1 Put the flame photom
40、eter into operation, using the identical burner and instrument settings that were determined duringcalibration in accordance with 8.2. Vaporize the medium-range standard solution (8.2) and adjust the sensitivity control to give thesame scale reading that was obtained when the calibration curve was p
41、repared.9.2.2 Atomize a portion of the sample solution prepared in 9.1.4 in the flame photometer. If it is in the optimum range for theinstrument in use, proceed as directed in 9.2.3. If it is too concentrated, place a few millilitres in a graduated cylinder, dilute toa known volume with water, and
42、atomize. If necessary, repeat this operation to determine the correct dilution. When this isestablished, make the proper accurate dilution by pipetting an aliquot from the original 100-mL100 mL volumetric flask intoanother volumetric flask and dilute to the mark with water.9.2.3 Atomize the properly
43、 diluted sample solution, record the scale reading, and obtain the sodium concentration in milligramsper litre by reference to the standard curve prepared in 8.4.Also atomize standards just lower and higher than the unknown to checkthe validity of the calibration curve.9.2.4 Perform a blank determin
44、ation on all of the reagents, including the water, in accordance with the procedure just described.10. Quality Control10.1 Confirm the performance of the test procedure by analyzing a quality control sample that is stable and representative ofthe sample of interest.10.1.1 When the quality control/qu
45、ality assurance protocols are already established in the testing facility, these may be used toconfirm the reliability of the test results.10.1.2 When there is no quality control/quality assurance protocol established in the testing facility, Appendix X1 can be usedto perform this function.11. Calcu
46、lation and Report11.1 Calculate the sodium concentration, in parts per million as follows:Sodium,mg in sample5A 2B! 3CE#/1000D (2)Sodium,mg/kg5mg of sodium31000!/Wwhere:A = sodium concentration of the sample solution, mg/L,B = sodium concentration in the reagent blank, mg/L,D1318 163C = volume to wh
47、ich ashed sample was originally diluted, mL,D = volume of aliquot taken from original dilution, mLE = volume to which aliquot D was diluted, mL andW = weight of sample used, g,11.2 Report the results to the nearest 1 1 mgmg/kg.kg.12. Precision and Bias12.1 PrecisionThe following criteria should be u
48、sed for judging the acceptability of results (95 % confidence):12.1.1 RepeatabilityThe difference between successive test results, obtained by the same operator with the same apparatusunder constant operating conditions on identical test material, would, in the long run in the normal and correct ope
49、ration of thetest method, exceed the following values only in one case in twenty:Sodium, mg/kg Repeatability, mg/kg15 to 40 440 to 85 612.1.2 ReproducibilityThe difference between two single and independent results, obtained by different operators working indifferent laboratories on identical test material, would, in the long run in the normal and correct operation of the test method,exceed the following values only in one case in twenty:Sodium, ppm Reproducibility, ppm15 to 25 925 to 50 1550 to 90 2312.2 BiasSince
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