1、Designation: D 5435 03 (Reapproved 2008)Standard Test Method forDiagnostic Soil Test for Plant Growth and Food ChainProtection1This standard is issued under the fixed designation D 5435; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, 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. Scope*1.1 This test method covers the determination of quantity(Q) and intensity (I) results for several eleme
3、nts in soils, spoils,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 as thestandard.1.3 This standard does not purport to address all of thesafe
4、ty problems, 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 653 Terminology Relating to So
5、il, Rock, and ContainedFluidsD 3740 Practice for Minimum Requirements for AgenciesEngaged in the Testing and/or Inspection of Soil and Rockas Used in Engineering Design and ConstructionE 617 Specification for Laboratory Weights and PrecisionMass Standards2.2 EPA Standard:U.S. EPA Method 3050 A33. Su
6、mmary of Test Method3.1 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 metal
7、sfrom the solid 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 val
8、uesanalogous to pH may be calculated using the ligand constantsfor the respective elements.4. Significance and Use4.1 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 p
9、otential (pi for 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 te
10、stmethod is the 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
11、 vegetationhas been 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 essentialel
12、ements for plants 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.4.2 The quality of the result produc
13、ed by this standard isdependent on the competence of the personnel performing it,and the suitability of the equipment and facilities used.Agencies that meet the criteria of Practice D 3740 are generallyconsidered capable of competent and objective testing/sampling/inspection and the like. Users of t
14、his standard arecautioned that compliance with Practice D 3740 does not in1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.22 on Soil as a Mediumfor Plant Growth.Current edition approved Feb. 1, 2008. Published Marc
15、h 2008. Originallyapproved in 1993. Last previous edition approved in 2003 as D 5435 03.2For 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 standards Document Summa
16、ry 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.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harb
17、or Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.itself assure reliable results. Reliable results depend on manyfactors; Practice D 3740 provides a means of evaluating someof those factors.5. Interferences5.1 Quality control in reagent preparation is more difficultthan for meth
18、ods that involve fewer elements and compounds.External contamination is a problem to be anticipated. Rubberis a source of Zn and Cd contamination. Rubber gloves used toremove glassware from an acid bath must be removed forsubsequent rinse procedures. The blank solution should betested for Na and oth
19、er elements. Often the superfloc containsNa which should be removed by use of a cation exchange resin.In addition the filter paper should be checked for Na.5.2 The cross contamination from glassware is a seriousproblem.All glassware is soaked in 1 + 1 HNO3for 2 h; rinsedwith distilled water three ti
20、mes followed with rinsing indistilled, deionized water three times. Remove rubber glovesafter first rinsing with distilled water to prevent contaminationwith Zn.5.3 The testing solution should be prepared fresh everyweek. Limited studies indicate that the relative amounts of thedifferent elements de
21、sorbed from soils by DTPA change as theprepared solution ages.5.4 The effect of Ca and other ions on the atomic absorptiondetermination of Cd is significant and requires that an adjust-ment be made. Background correction will eliminate thissource of error.5.5 The TEA (triethanolamine) is used to pre
22、vent excessivedissolution of trace metals from high p-H soils. The buffercapacity is not sufficient, however, to prevent a reflection ofsoil acidity on trace element availability in soil.5.6 For some soils the colorimetric determination of phos-phorus is not adequate because of the development of tu
23、rbiditywith stannous chloride used as the reducing agent or when P isvery near the detection limit of 1 m/L. Other reducing agentsas proposed byWatanabe and Olsen (1)4or the isobutyl alcoholextraction method as proposed for water soluble P (see section12.9) have been used with limited success on the
24、se samples.6. Apparatus6.1 No. 10 Sieve, (U.S. Sieve Series Standard 2 mm)constructed from polyethylene.6.2 Erlenmeyer Flasks, 125-mLcapacity with polyethylene-covered rubber stoppers or equivalent.6.3 Rotating Shaker, 150 rpm for 125-mL flasks.6.4 Filter Funnels,11cm.6.5 Filter Paper,515 cm in diam
25、eter.6.6 Sample Storage Bottles, 50 mL polyethylene.6.7 pH Meter, with reference and glass electrodes, that isaccurate to 60.02-pH units when standardized against pH 4.01and pH 7.00 buffers.6.8 Precise Automatic Diluter, for use with soil test solu-tions and standards 1:50 in SrCl2solution for Mg an
26、d Cadeterminations by flame AA or ICP.6.9 Automatic Diluter, accurate, calibrated, for diluting soiltest solutions that are above the range of the working standards.6.10 Atomic Absorption or ICP Spectrometer, equippedwith background correction.6.11 Colorimeter, with 2-cm light-path cells or autoanal
27、yzerfor colorimetric analyses.6.12 Analytical and Top-Loading Balances, accuracy to beverified using Specification E 617 weights.6.13 50-mL Test Tubes, 15-mL Volumetric Pipettes, and 1-mL Measuring Pipettes, for use in P determinations.6.14 50-mL Erlenmeyer Flasks, 10-mL Volumetric Pipettes,and 1-mL
28、 Measuring Pipettes, for S determination.6.15 Various Beakers, Erlenmeyer flasks, graduated cylin-ders, volumetric pipettes, flasks, storage bottles, magneticheating and stirring unit, refrigerator, and other equipment asrequired for preparing and storing stock solutions, soil testsolutions, reagent
29、s, and standards.6.16 Computer FacilitiesComputer software that is com-patible with IBM-PC and mainframe computers is available toproduce the chemical potentials (negative logarithm of theactivity of respective ions in soil or substrate solutions) isavailable. The software is beneficial in producing
30、 output thatprovides decision support for users of this test method.7. Reagents and Materials7.1 Stock SolutionsPrepare the following stock solutionsby dissolving the indicated amount of the pure salt in purewater and diluting to 1 L:Stock Solution Amount of Salt per Litre of Solution0.10 M NaCl 5.8
31、4 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 solutionsenables a more constant pH to be achieved when TEAis addedthan the use of compound
32、s 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 meet the required final concentrations.7.2 Primary StandardsUse commercial primar
33、y 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 water. Prepare 1000 mg/L stocksolutions of Mn, Fe, Ni, and Cu by dissolving 1.000 g
34、 of thepure metal in 1:1 concentrated HNO3-water mixture anddiluting to 1 L with pure water.7.3 DTPA, diethylenetriaminepentaacetic acid.7.4 TEA (0.0275 M TEA)Dissolve 4.101 g of TEAin purewater and dilute to 1 L.7.5 Superfloc-127 Solution, 1 %To 700 mL of pure waterin a 1-L beaker on a magnetic sti
35、rring 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 glass4The boldface numbers in parentheses refer to a list of references at the end ofthis test method.5The sole source of supply of the apparatus known
36、to the committee at this timeisS 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.10.2 Baker Soil Test Equilibration Weigh 5
37、.000 g of soil( 2 mm) into a 125-mL 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 10.1).Add 5.0 mLof soil testsolution to the flask. Add to the flask the
38、amount of 0.0275 MTEA needed to obtain 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 10.1). Stopper the blank and sample flaskswith plastic stoppers and place on a rotating shaker for1hat150 oscillations per minute. Allow the flask
39、s to stand for anadditional 21 to 23 h and filter the samples through filterpaper.510.3 pHDetermine the pH of an aliquot of sample using apH meter and glass and reference electrodes standardizedagainst pH 4.01 and 7.0 buffers.10.4 Elemental AnalysisThe actual analysis of samplewill vary with instrum
40、entation. Na and K may be analyzed byflame emission spectroscopy; for Ca and Mg by FlameAA, thetest solution and standards may need to be diluted 1:50 in theSrCl2diluting solution using a precise automatic diluter. BothCa and Mg may be determined by Flame AA. All otherelements may be determined by F
41、lame or Flameless AA, orboth, depending on the concentrations in solution as well as byICP.10.5 Na and KThese two elements are easily determinedin the blank and soil test solution samples by flame emissionspectroscopy.10.6 Mg and CaDilute the standards and blank and soiltest solutions samples 1:50 i
42、n the SrCl2diluting solution usinga precise automatic diluter. Determine the concentrations ofthese elements in the blank and samples by atomic absorptionspectrophotometry or by ICP.10.7 Al, Mn, Fe, Ni, Cu, Zn, and CdDetermine theconcentration of these elements in the blank and soil testsolution sam
43、ples by atomic absorption spectrophotometry.10.8 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
44、2-cm light path after 6 but before 11min.10.9 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).Let stand for exactly 1 min, mix until the crystals are dissolved,and read the absorben
45、cies on a colorimeter at 420 mu between2 and 8 min using a cell with a 2-cm light path.11. Calculation11.1 Report the results in the units of the standards for P, K,Ca, and Mg. For the trace elements, report the soil levels arereported (solution levels: x 10.0). If filtrates are diluted, thedilution
46、 factor must be applied.11.2 Computer programs are available to perform the itera-tive calculations required to produce values for pH, pK, pCa,pMg, pFe, pMn, etc.The validity of these conversions has beenverified using numerous samples from research investigationsand thousands of user samples. Use o
47、f this computerized expertsystem provides an intensity value, and a desorbed quantityamount for most elements and relative intensity values for K,Ca, Mg, and H. In addition, data for Total Sorbed Metals by theD 5435 03 (2008)4U.S. Environmental Protection Agency (EPA) method is in-cluded. See Footno
48、te7for information regarding the computerprogram. The iterative procedure may also be performed usingprogram GEOCHEM-PC (2, 3).7See Footnote 10 for informa-tion regarding the computer program to provide the decisionsupport output from the database for the method.12. Interpretation of Results12.1 For
49、 those that do not have access to the computerprograms Table 2 shows interpretation offered with respect toplant growth and food-chain protection.12.2 As indicated in 11.2, the Baker Soil Test8softwareallows the inclusion of total sorbed metals by U.S. EPAMethod 3050A. The above interpretative data represent “smallexchange” calibration values from the existing data for over10 000 samples. The numbers given here do not refer to totalmetal content of a soil sample or the results by U.S. EPAMethod 3050A, and should not be compared with previouslypublished ranges of s
