1、July 2009DEUTSCHE NORM English price group 10No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 13.080.10!$XC$“1533201www
2、.din.deDDIN ISO 19730Soil quality Extraction of trace elements from soil using ammonium nitrate solution(ISO 19730:2008)English version of DIN ISO 19730:2009-07Bodenbeschaffenheit Extraktion von Spurenelementen aus Bden mit Ammoniumnitratlsung (ISO 19730:2008)Englische Fassung DIN ISO 19730:2009-07S
3、upersedesDIN 19730:1997-06www.beuth.deDocument comprises pages16Contents Page National foreword 3 Introduction 5 1 Scope7 2 Normative references7 3 Principle7 4 Reagents.8 5 Apparatus.8 6 Procedure.8 6.1 Sample preparation .8 6.2 Determining water content .9 6.3 Extraction .9 6.4 Phase separation.9
4、6.5 Stabilization of extract 9 6.6 Blank test9 7 Calculation .9 8 Expression of results10 9 Test report10 Annex A (informative) Information on method of determining selected elements and treatment of particular types of soil 11 Annex B (informative) Precision12 Annex C (informative) Notes on homogen
5、ization, initial sample mass and extraction.14 Bibliography15 DIN ISO 19730:2009-07 2National foreword This standard has been prepared by Technical Committee ISO/TC 190 “Soil quality”, Subcommittee SC 3 “Chemical methods and soil characteristics”. The responsible German body involved in its preparat
6、ion was the Normenausschuss Wasserwesen (Water Practice Standards Committee), Technical Committee NA 119-01-02-02 UA Chemische und physikalische Verfahren. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. DIN shall not be held resp
7、onsible for identifying any or all such patent rights. Expert assistance and specialized laboratories will be required to perform the sampling procedures described in this standard. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 3696 D
8、IN ISO 3696 ISO 5725-1 DIN ISO 5725-1 ISO 5725-2 DIN ISO 5725-2 ISO 5725-3 DIN ISO 5725-3 ISO 5725-4 DIN ISO 5725-4 ISO 5725-5 DIN ISO 5725-5 ISO 5725-6 DIN ISO 5725-6 ISO 11047 DIN ISO 11047 ISO 11464 DIN ISO 11464 ISO 11465 DIN ISO 11465 ISO 17294-2 DIN EN ISO 17924-2 ISO 20280 E DIN ISO 20280 ISO
9、 22036 DIN ISO 22036 Amendments This standard differs from DIN 19730:1997-06 as follows: a) The title of the standard has been modified. b) The standard has been revised in form and substance. c) Annex A (informative) has been extended to include standardized methods for the determination of trace e
10、lements in ammonium nitrate extracts. Previous editions DIN V 19730: 1993-02 DIN 19730: 1997-06 DIN ISO 19730:2009-07 3National Annex NA (informative) Bibliography DIN ISO 3696, Water for analytical laboratory use Specification and test methods DIN ISO 5725-1, Accuracy (trueness and precision) of me
11、asurement methods and results Part 1: General principles and definitions DIN ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method DIN ISO 5725-3, Accuracy (tru
12、eness and precision) of measurement methods and results Part 3: Intermediate measures of the precision of a standard measurement method DIN ISO 5725-4, Accuracy (trueness and precision) of measurement methods and results Part 4: Basic methods for the determination of the trueness of a standard measu
13、rement method DIN ISO 5725-5, Accuracy (trueness and precision) of measurement methods and results Part 5: Alternative methods for the determination of the precision of a standard measurement method DIN ISO 5725-6, Accuracy (trueness and precision) of measurement methods and results Part 6: Use in p
14、ractice of accuracy values DIN ISO 11047, Soil quality Determination of cadmium, chromium, cobalt, copper, lead, manganese, nickel and zinc in aqua regia extracts of soil Flame and electrothermal atomic absorption spectrometric methods DIN ISO 11464, Soil quality Pretreatment of samples for physico-
15、chemical analyses DIN ISO 11465, Soil quality Determination of dry matter and water content on a mass basis Gravimetric method DIN EN ISO 17294-2, Water quality Application of inductively coupled plasma mass spectrometry (ICP-MS) Part 2: Determination of 62 elements E DIN ISO 20280, Soil quality Det
16、ermination of arsenic, antinomy and selenium in aqua regia soil extracts with electrothermal or hydride-generation atomic absorption spectrometry DIN ISO 22036, Soil quality Determination of trace elements in extracts of soil by inductively coupled plasma-atomic emission spectrometry (ICP-AES) DIN I
17、SO 19730:2009-07 4Introduction 0.1 General The displacement of trace elements in soil cannot be described solely in terms of their solubility in water, since solid and dissolved compounds interact with one another in a large number of processes. Processes that proceed in one direction (e.g. weatheri
18、ng, mineralization) are accompanied by equilibrium reactions between solid and dissolved forms (e.g. adsorption/desorption, precipitation/dissolution). Factors that determine whether substances dissolve include the pH value, the redox potential, the concentration of ions in a soil solution and its c
19、omplexing agent content, all of which result in the soil solution varying with location and time. To be able to compare increases in easily soluble trace element concentrations in soil by a standardized method, soil extraction with ammonium nitrate is used, which is applicable to all those compounds
20、 of elements in a soil that may contribute to the concentration of dissolved elements under the prevailing site conditions (water-soluble compounds, exchangeably bound ions, readily soluble metal complexes). Extraction with ammonium nitrate solution fulfils the criteria to be satisfied by an extract
21、ant for routine analyses. a) It can be applied to a wide spectrum of soils and elements in a wide concentration range. b) Disposal of the spent ammonium nitrate solution is environmentally friendly. c) The determination of the elements in the solution has low susceptibility to interference. The conc
22、entrations of elements in extracts obtained with other unbuffered salt solutions (such as calcium chloride or sodium nitrate solution) often correlate well with those in ammonium nitrate extracts, but the absolute concentrations are different and, at some sites, there may be concentrations deviating
23、 substantially from average values. In addition, critical concentrations may be in the region of the limit of determination in the case of some extraction methods. In conjunction with extraction methods for determining the reserves of elements in soil (e.g. extraction with aqua regia), the proportio
24、ns by mass determined by extraction with ammonium nitrate solution can serve as a basis for site investigations and for making recommendations with regard to use and restoration of soil containing critical concentrations of elements. 0.2 Prediction of impact 0.2.1 General The concentrations determin
25、ed by extraction with ammonium nitrate solution only provide an indication of the effects of trace elements, since it is necessary also to consider numerous site factors and sometimes the amounts of elements present in the soil in order to predict impact. Thus, designations such as “biologically ava
26、ilable”, “available to plants” or “components capable of migration” are not appropriate. In soil that is sometimes poorly aerated (e.g. water-logged soil), variations in the redox potential need to be considered when assessing the potential of arsenic and manganese to migrate. Soil quality Extractio
27、n of trace elements from soil using ammonium nitrate solution DIN ISO 19730:2009-07 50.2.2 Migration of elements Extraction with ammonium nitrate solution has been found to be a suitable method of assessing easily soluble trace element fractions of a soil, whose element concentrations should be dete
28、rmined from samples of undisturbed soil taken from adequately distant sites and at different times. Major factors governing the transport of elements via seepage water are: their chemical and physical properties; the thickness of the unsaturated zone; the distribution of easily soluble elements over
29、 the depth of the soil; and the actual speed with which the seepage water travels. The easily soluble trace element fractions in soil vary with time and location. Increased variability can generally be expected with varying soil acidity (e.g. in soil covered by forest vegetation) or hydromorphic mod
30、ification (e.g. in warp soil), and can also be expected where the amounts of elements in the soil vary (e.g. due to mineralization). This should be considered when designing a sampling programme. DIN ISO 19730:2009-07 61 Scope This International Standard specifies a method of extracting trace elemen
31、ts from soil using a 1 mol/l NH4NO3solution (see the Introduction). NOTE Information on determining selected elements and treatment of particular types of soil is given in Annex A. 2 Normative references The following referenced documents are indispensable for the application of this document. For d
32、ated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3696:1987, Water for analytical laboratory use Specification and test methods ISO 11464:1994, Soil quality Pretreatment of samples for physic
33、o-chemical analyses ISO 11465, Soil quality Determination of dry matter and water content on a mass basis Gravimetric method 3 Principle The soil sample with particle size 99 %, whose purity has been established in preliminary tests) in water and make the solution up to 1 l with water. As an alterna
34、tive, ready-to-use 1 mol/l high purity ammonium nitrate solution may be used. 4.3 Nitric acid, wHNO3= 65 %, HNO3 1,4 g/ml. 4.4 Nitric acid, diluted, = 5 %. Dilute 50 ml of nitric acid (4.3) up to 1 l with water. 5 Apparatus The following equipment shall be used. 5.1 Forced-circulation drying oven, c
35、apable of being maintained at a temperature of (30 2) C. 5.2 Pestle and mortar, made of porcelain or sintered corundum. 5.3 Screens, having an aperture size of 2 mm for air-dried samples and of 5 mm to 8 mm for freshly collected samples, and which do not cause contamination by the elements to be det
36、ermined. 5.4 Balance, of accuracy 0,01 g. 5.5 Conical test tubes with screw caps, of nominal capacity 50 ml, made of polypropylene (or high density polyethylene, polytetrafluoroethylene, perfluoroalkoxyalkane, or tetrafluoroethylene/hexafluoropropylene copolymer). Before use, check cleanliness of tu
37、bes and caps. If cleaning is necessary, fill the test tubes with dilute nitric acid (4.4) and allow to stand for 24 h, then wash with water and dry. 5.6 End-over-end shaker, capable of (20 2) r/min, placed in a thermostatically controlled room (20 2) C. 5.7 In-line membrane filter, for connection wi
38、th a disposable syringe. Connect an in-line membrane filter of pore size 0,45 m to a disposable syringe with Luer-lock joint. If necessary, clean the membrane filter and the syringe by rinsing with dilute nitric acid (4.4). If colloids are present in the filtrate, use a 0,2 m membrane filter. High d
39、ensity filter papers can be used if they are tested and proved to be free of the elements to be determined. 5.8 Disposable plastic syringe, of nominal volume 10 ml or 20 ml, with Luer-lock joint. 5.9 Centrifuge, able to centrifuge the test tubes (5.5) at 1 000 g to 3 000 g. 6 Procedure 6.1 Sample pr
40、eparation The soil sample should be pretreated in accordance with ISO 11464. Use the soil fraction with grain size 2 mm. Extract soil samples from organic horizons (having more than 30 % by mass of organic matter, such as bog soil or topsoil and samples from reductomorphic horizons horizons affected
41、 by backwater or ground water such as coastal marsh soil or gley soil) in the freshly collected state and homogenize as described in Annex C. 6.2 Determining water content Determine the water content in accordance with ISO 11465. DIN ISO 19730:2009-07 86.3 Extraction Extract the soil at (20 2) C wit
42、h 1 mol/l NH4NO3solution, using a mass-to-volume ratio of 1:2,5. Using a pipette, add 25,0 ml of ammonium nitrate solution (4.2) to (10,00 0,01) g of air-dried or freshly collected soil (6.1) into a 50 ml conical test tube with screw caps (5.5). Close the test tube with a screw cap, mount it to an e
43、nd-over-end shaker (5.6) and extract the soil at (20 2) r/min for (120 5) min. See Annex C for instructions on extracting organic or reductomorphic horizons. 6.4 Phase separation Place the closed test tubes into a centrifuge and separate the solid phase by centrifugation with about 1 000 g for 10 mi
44、n. Rinse the membrane filter and the syringe with 1 ml of extract solution and discard the rinsing solution. Filter 10 ml of the supernatant solution directly from the sample test tube into a 10 ml syringe equipped with a 0,45 m disposable in-line membrane filter. Store the filtered ammonium nitrate
45、 extract in a clean conical test tube. 6.5 Stabilization of extract After filtration, stabilize the extract with nitric acid (4.3) by adding about 1 % of its volume of nitric acid (e.g. 0,1 ml of nitric acid to 10 ml of extract). This can also be done in connection with a dilution step (especially n
46、ecessary if ICP techniques are applied for analysis). Transfer a fixed volume of the filtrate (e.g. 10,0 ml) using a pipette into a 50 ml volumetric flask, add 0,5 ml nitric acid (4.3) and fill up to the mark with water. Dilutions can be made also by mass. 6.6 Blank test Subject at least one blank t
47、o the same extraction procedure. 7 Calculation After subtracting the blank concentration of an element from the concentration of the sample solution, calculate the extractable element fraction, wx, expressed in g/kg of dry matter, determined in accordance with ISO 11465. For air-dried soil samples,
48、use Equation (1) and for wet, freshly collected samples use Equation (2) air-dried sample: ()2BHOx0100100VF wwm +=(1) wet, fresh sample: 22HOxBdHO100wVwFm=+(2) with water content, in %:20dHOd100mmwm= (3) where wxis the ammonium nitrate extractable mass fraction of an element (x) in soil, in g/kg; Bi
49、s the blank-corrected concentration of the element in the analysis solution, in g/l; V is the volume of ammonium nitrate solution added to the soil sample, in litres (nominal 0,025 l); DIN ISO 19730:2009-07 9F dilution factor, Vend/Vi: Viis the volume of the aliquot take of NH4NO3solution, diluted to volume Vendfor use in the analysis; m0is the initial mass of the air-dried or freshly collected soil, in kg; mdis the mass of soil, dried in accordance with ISO 11465, in kg; 2HOw is t
