1、Designation: D5435 13Standard Test Method forDiagnostic Soil Test for Plant Growth and Food ChainProtection1This standard is issued under the fixed designation D5435; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、 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 the determination of quantity(Q) and intensity (I) results for several elements in soils, spoils,
3、fly-ash, and other soil substitutes to ascertain their suitabilityfor the growth of vegetation and possible adverse effects ofmetals on the food chain.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 All measured and calc
4、ulated values shall conform to theguidelines for significant digits and rounding established inPractice D6026.1.4 This standard does not purport to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safet
5、y and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and ContainedFluidsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and R
6、ock asUsed in Engineering Design and ConstructionD6026 Practice for Using Significant Digits in GeotechnicalDataE617 Specification for Laboratory Weights and PrecisionMass Standards3. Terminology3.1 For definitions of common terms used in this standard,refer to Terminology D653.4. Summary of Test Me
7、thod4.1 Arepresentative sample material to be tested is air dried,sieved to pass a 2-mm screen, equilibrated for 16 to 20 h withthe soil test solution containing the optimum activities (I) ofH3O+,Ca+,Mg+,K+and DTPA (diethyl-enetriaminepentaacetate) to render a small exchange of metalsfrom the solid
8、phase to the solution phase. This test method iscalibrated with respect to pH, K, Ca, Mg, H/(Ca + Mg)1/2,Mg/K, Ca/Mg, Mn, Fe, Cu, Zn,Al, Pb, Ni, and Cd. In additionto the exchangeable or labile amounts (Q), or both, of the sameelements, comparable levels of the negative logarithm valuesanalogous to
9、pH may be calculated using the ligand constantsfor the respective elements.5. Significance and Use5.1 The bioavailability of chemical elements is poorlyrelated to the chemical composition of soils and plant growthmedia containing a mineral or any type of adsorbed phase. Thechemical potential (pi for
10、 element, i,) is an intensity parameter(I), and the sorbed amount in equilibrium with the soil solutionis a measure of the quantity (Q). These parameters for eachelement (essential or toxic) should be measured in the presenceof other elements at or near the desired intensity. This testmethod is the
11、only method that generates these results simul-taneously for several elements. The computer software allowsthese values to be related to the total sorbed quantities of thedifferent elements. For many substrates, it has been found thatthe theory for the method holds to the degree that vegetationhas b
12、een established on many non-soil substrates and soil-water-food chain problems have been evaluated by this testmethod. This test method has been used on many sites inPennsylvania and other locations to monitor the effect ofsewage sludge applications on land as a source of essentialelements for plant
13、s with no harmful effects on the food chain.It has also been used to evaluate synthetic soils produced fromfly-ash alone or as a component of coal refuse for theestablishment of vegetation on mine spoils, coal refuse piles,and abandoned mine lands.NOTE 1The quality of the result produced by this sta
14、ndard isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competent1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock
15、and is the direct responsibility of Subcommittee D18.22 on Soil as a Mediumfor Plant Growth.Current edition approved Nov. 1, 2013. Published December 2013. Originallyapproved in 1993. Last previous edition approved in 2008 as D5435 03 (2008).DOI: 10.1520/D5435-13.2For referenced ASTM standards, visi
16、t the ASTM 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 10
17、0 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1and objective testing/sampling/inspection and the like. Users of thisstandard are cautioned that compliance with Practice D3740 does not initself assure reliable results. Reliable results depend on many factors;Practic
18、e D3740 provides a means of evaluating some of those factors.6. Interferences6.1 Quality control in reagent preparation is more difficultthan for methods that involve fewer elements and compounds.External contamination is a problem to be anticipated. Rubberis a source of Zn and Cd contamination. Rub
19、ber gloves used toremove glassware from an acid bath must be removed forsubsequent rinse procedures. The blank solution should betested for Na and other elements. Often the superfloc containsNa which should be removed by use of a cation exchange resin.In addition the filter paper should be checked f
20、or Na.6.2 The cross contamination from glassware is a seriousproblem.All glassware is soaked in 1 + 1 HNO3for 2 h; rinsedwith distilled water three times followed with rinsing indistilled, deionized water three times. Remove rubber glovesafter first rinsing with distilled water to prevent contaminat
21、ionwith Zn.6.3 The testing solution should be prepared fresh everyweek. Limited studies indicate that the relative amounts of thedifferent elements desorbed from soils by DTPA change as theprepared solution ages.6.4 The effect of Ca and other ions on the atomic absorptiondetermination of Cd is signi
22、ficant and requires that an adjust-ment be made. Background correction will eliminate thissource of error.6.5 The TEA (triethanolamine) is used to prevent excessivedissolution of trace metals from high p-H soils. The buffercapacity is not sufficient, however, to prevent a reflection ofsoil acidity o
23、n trace element availability in soil.6.6 For some soils the colorimetric determination of phos-phorus is not adequate because of the development of turbiditywith stannous chloride used as the reducing agent or when P isvery near the detection limit of 1 m/L. Other reducing agentsas proposed byWatana
24、be and Olsen (1)3or the isobutyl alcoholextraction method as proposed for water soluble P have beenused with limited success on these samples.7. Apparatus7.1 2 mm (No. 10 Sieve), constructed from polyethylene.7.2 Erlenmeyer Flasks, 125-mLcapacity with polyethylene-covered rubber stoppers or equivale
25、nt.7.3 Rotating Shaker, 150 rpm for 125-mL flasks.7.4 Filter Funnels, 11 cm.7.5 Filter Paper,415 cm in diameter.7.6 Sample Storage Bottles, 50 mL polyethylene.7.7 pH Meter, with reference and glass electrodes, that isaccurate to 60.02-pH units when standardized against pH 4.01and pH 7.00 buffers.7.8
26、 Precise Automatic Diluter, for use with soil test solu-tions and standards 1:50 in SrCl2solution for Mg and Cadeterminations by flame AA or ICP.7.9 Automatic Diluter, accurate, calibrated, for diluting soiltest solutions that are above the range of the working standards.7.10 Atomic Absorption or IC
27、P Spectrometer , equippedwith background correction.7.11 Colorimeter, with 2-cm light-path cells or autoanalyzerfor colorimetric analyses.7.12 Analytical and Top-Loading Balances, accuracy to beverified using Specification E617 weights.7.13 50-mL Test Tubes, 15-mL Volumetric Pipettes, and 1-mL Measu
28、ring Pipettes, for use in P determinations.7.14 50-mL Erlenmeyer Flasks, 10-mL Volumetric Pipettes,and 1-mL Measuring Pipettes, for S determination.8. Reagents and Materials8.1 Stock SolutionsPrepare the following stock solutionsby dissolving the indicated amount of the pure salt in purewater and di
29、luting to 1 L:Stock Solution Amount of Salt per Litre of Solution0.10 M NaCl 5.84 g of NaCl0.25 M KCl 18.64 g of KCl1.00 M MgCl2203.31 g of MgCl26H2O2.00 M CaCl2294.04 g of CaCl22H2O0.010 M KH2PO41.3609 g of KH2PO41000 mg/1 s 5.435 g of K2SO4The use of the above reagents to prepare stock solutionsen
30、ables a more constant pH to be achieved when TEAis addedthan the use of compounds considered to provide standards ofmore accurate composition. Since the chloride salts are notsuitable for primary standards, they should be compared withreliable, primary standards and the volumes used are adjustedto m
31、eet the required final concentrations.8.2 Primary StandardsUse commercial primary standardsfor AA or ICP applications, or both, or prepare 1000-mg/Lstock solutions of Al, Zn, and Cd by dissolving 1.000 g of thepure metal in 50 mL of 1:1 concentrated HCl-water mixtureand diluting to 1 L with pure wat
32、er. Prepare 1000 mg/L stocksolutions of Mn, Fe, Ni, and Cu by dissolving 1.000 g of thepure metal in 1:1 concentrated HNO3-water mixture anddiluting to 1 L with pure water.8.3 DTPA, diethylenetriaminepentaacetic acid.8.4 TEA (0.0275 M TEA)Dissolve 4.101 g of TEAin purewater and dilute to 1 L.8.5 Sup
33、erfloc-127 Solution, 1%To 700 mL of pure waterin a 1-L beaker on a magnetic stirring unit, slowly add 10.0 gof Superfloc-127, a small portion at a time, with continuousstirring and gentle heating. Cover the beaker with a watch glassand allow this solution to stir overnight. Transfer this solutionqua
34、ntitatively to a 1-L volumetric flask and dilute to 1 L. Storethis solution in the refrigerator. Dilute 10 mL of the solution to3The boldface numbers in parentheses refer to a list of references at the end ofthis standard.4The sole source of supply of the apparatus known to the committee at this tim
35、eisS if not, adjust theamount of 0.0275 M TEA and pure water used to obtain a pHof 7.3 6 0.05 in a final volume of 50.0 mLof soil test solution.Greater precision can be achieved by working with 1-Lvolumes for 20 samples at a time.11.2 Soil Test EquilibrationWeigh 5.000 g of soil ( 2mm) into a 125-mL
36、 Erlenmeyer flask. Add to the flask theamount of pure water needed to obtain a pH of 7.3 6 0.05 anda final volume of 50.0 mL with no soil present as determinedin the blank preparation step (see 11.1).Add 5.0 mLof soil testsolution to the flask. Add to the flask the amount of 0.0275 MTEA needed to ob
37、tain a pH of 7.3 6 0.05 and a final volumeof 50 mL with no soil present as determined in the blankpreparation step (see 11.1). Stopper the blank and sample flaskswith plastic stoppers and place on a rotating shaker for1hat150 oscillations per minute. Allow the flasks to stand for anadditional 21 to
38、23 h and filter the samples through filterpaper.411.3 pHDetermine the pH of an aliquot of sample using apH meter and glass and reference electrodes standardizedagainst pH 4.01 and 7.0 buffers.11.4 Elemental AnalysisThe actual analysis of sample willvary with instrumentation. Na and K may be analyzed
39、 by flameemission spectroscopy; for Ca and Mg by Flame AA, the testsolution and standards may need to be diluted 1:50 in the SrCl2diluting solution using a precise automatic diluter. Both Ca andMg may be determined by Flame AA. All other elements maybe determined by Flame or Flameless AA, or both, d
40、ependingon the concentrations in solution as well as by ICP.11.5 Na and KThese two elements are easily determinedin the blank and soil test solution samples by flame emissionspectroscopy.11.6 Mg and CaDilute the standards and blank and soiltest solutions samples 1:50 in the SrCl2diluting solution us
41、inga precise automatic diluter. Determine the concentrations ofthese elements in the blank and samples by atomic absorptionspectrophotometry or by ICP.11.7 Al, Mn, Fe, Ni, Cu, Zn, and Cd Determine theconcentration of these elements in the blank and soil testsolution samples by atomic absorption spec
42、trophotometry.11.8 PAdd 0.5 mL of the ammonium molybdate reagentto 15.00 mL each of blank and soil test solution samples andeach P standard, and mix.Add 0.3 mL of the stannous chloridereagent, mix, and read the absorbencies on a colorimeter at660-mu using a cell with a 2-cm light path after 6 but be
43、fore 11min.11.9 Sulfate, SAdd 1 mLof acid seed reagent to 10.00 mLof blank and sample soil test solutions and each S standard,mix, and add 0.5 g of BaCl22H2O crystals (20 to 60 mesh). Letstand for exactly 1 min, mix until the crystals are dissolved,and read the absorbencies on a colorimeter at 420 m
44、u between2 and 8 min using a cell with a 2-cm light path.12. Interpretation of Results12.1 Table 2 shows interpretation offered with respect toplant growth and food-chain protection.12.2 The above interpretative data represent “small ex-change” calibration values from the existing data for over 1000
45、0 samples. Critical levels for the quantity values presentedabove, based on field response data, varies with crops and localfield conditions. The low levels are not usually deficient andhigh levels are not usually toxic.13. Effects of Storage13.1 Soil samples may be stored in an air-dry condition fo
46、rprolonged periods with no effect on test levels of the differentelements. However, maintaining samples in a wet condition atroom temperature renders the results for Mn, Fe, Cu, P andpossibly other elements unreliable. Differences between moistand air-dried samples have been found, especially for Mn
47、 andAl.D5435 13414. Report: Test Data Sheet(s)/Form(s)14.1 Record as a minimum the following general informa-tion:14.1.1 Sample/specimen identifying information, such asProject No., Boring No., Sample No., Depth, etc.14.1.2 Any special selection and preparation process, suchas removal of gravel or o
48、ther materials.14.1.3 Technician name, and date.14.1.4 Report the quantities (Q) and intensities (I) of eachtest element.15. Precision and Bias15.1 PrecisionThe within laboratory standard deviationsand maximum allowable differences are as follows:Element Standard Deviation Maximum DifferenceK 0.088
49、0.23Ca 1.691 4.40Mg 0.661 1.72Mn 2.184 5.68Fe 0.176 0.458Cu 0.016 0.042Zn 0.042 0.109Na 0.266 0.692Al 0.096 0.250Ni 0.021 0.055Pb 0.039 0.101Cd 0.042 0.10915.2 BiasThere is no acceptable reference value for thistest method; therefore, bias cannot be determined.16. Keywords16.1 diagnostic soil test; food chain; plantREFERENCES(1) Watanabe, F. S., and Olsen, S. R.,“ Colorimetric Determination ofPhosphorus in Water Extracts of Soil,” Soil Sci. 93, 1962, pp.183188.(2) Sposito, G., and Mattigod, S. V., GEOCHEM: A Computer Programfor the Calculation of Chemical Equil
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