EN 13650:2001
(Main)Soil improvers and growing media - Extraction of aqua regia soluble elements
Soil improvers and growing media - Extraction of aqua regia soluble elements
This European Standard specifies a method for the routine extraction of aqua regia soluble elements (as listed in annex B) from soil improvers or growing media. Materials containing more than about 28 % (m/m) organic matter will require treatment with additional nitric acid. With high solute concentrations in extract solutions, spectral interference's and background enhancement should be expected.
The method is not applicable to liming materials and preformed materials such as mineral wool slabs and foam slabs.
NOTE 1 Aqua regia will not totally dissolve most soil improvers or growing media, and the efficiency of extraction for particular elements differs from element to element. Such efficiency might also differ for the same element in different matrices. Elements extractable in aqua regia cannot therefore, be described as "Totals"; conversely they cannot be regarded as the "bio-available" fraction, as the extraction procedure is too vigorous to represent any biological process.
NOTE 2 The requirements of the standard may differ from the national legal requirements for the declaration of the products concerned.
Bodenverbesserungsmittel und Kultursubstrate - Extraktion von in Königswasser löslichen Elementen
Diese Europäische Norm legt ein Verfahren zur routinemäßigen Extraktion von in Königswasser löslichen Elementen
(wie im Anhang B angegeben) in Bodenverbesserungsmitteln oder Kultursubstraten fest. Materialien, die über etwa
28 % Massenanteil organische Substanz enthalten, erfordern eine Behandlung mit zusätzlicher Salpetersäure. Bei
hohen Konzentrationen an gelösten Stoffen in den Extraktlösungen sollten spektrale Störungen und Hintergrundver-
stärkungen erwartet werden.
Das Verfahren gilt nicht für Calcium-/Magnesium-Bodenverbesserungsmittel und vorgeformte Materialien wie Platten
aus Mineralwolle und Schaumplatten.
ANMERKUNG 1 Königswasser bringt die meisten Bodenverbesserungsmittel und Kultursubstrate nicht vollständig in Lösung, und die
Extraktionsausbeute ist für jedes Element verschieden. Die Ausbeute kann auch für dasselbe Element in unterschiedlichen Matrizes ver-
schieden sein. Mit Königswasser extrahierbare Elemente können daher nicht als Gesamtgehalte beschrieben werden; sie können jedoch
auch nicht als bioverfügbare Fraktion betrachtet werden, da das Extraktionsverfahren zu stark ist, als dass hierdurch biologische
Vorgänge beschrieben werden können.
ANMERKUNG 2 Die Anforderungen der Norm können von den nationalen gesetzlichen Vorgaben bezüglich der Deklaration der
erwähnten Produkte abweichen.
Amendements du sol et supports de culture - Extraction d'éléments solubles dans l'eau régale
La présente Norme européenne décrit une méthode pour l'extraction de routine d'éléments solubles dans l'eau régale (tels qu'énoncés à l'annexe B), d'amendements du sol ou de supports de culture. Les matériaux contenant plus d'environ 28 % (m/m) de matière organique nécessiteront un traitement avec de l'acide nitrique. Des interférences spectrales et un enrichissement du milieu sont prévus dans le cas de concentrations de soluté élevées dans des solutions d'extrait.
Cette méthode ne s'applique pas aux amendements calciques ni aux matériaux préformés tels que la laine de roche et les mousses.
NOTE 1 L'eau régale ne dissout pas complètement la plupart des amendements du sol ou supports de culture et l'efficacité de l'extraction pour les éléments particuliers diffère d'un élément à l'autre. Cette efficacité peut également varier pour le même élément dans des matrices différentes. Les éléments extractibles dans l'eau régale ne peuvent, par conséquent, pas être décrits comme « totaux » mais ne peuvent pas non plus être considérés comme la fraction « bio-disponible » car le mode opératoire d'extraction est trop vigoureux pour constituer un procédé biologique quelconque.
NOTE 2 Les exigences de la norme peuvent différer des obligations légales en vigueur pour la déclaration des produits concernés.
Izboljševalci tal in rastni substrati - Ekstrakcija elementov, topnih v zlatotopki
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2002
Izboljševalci tal in rastni substrati - Ekstrakcija elementov, topnih v zlatotopki
Soil improvers and growing media - Extraction of aqua regia soluble elements
Bodenverbesserungsmittel und Kultursubstrate - Extraktion von in Königswasser
löslichen Elementen
Amendements du sol et supports de culture - Extraction d'éléments solubles dans l'eau
régale
Ta slovenski standard je istoveten z: EN 13650:2001
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 13650
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2001
ICS 65.080
English version
Soil improvers and growing media - Extraction of aqua regia
soluble elements
Amendements du sol et supports de culture - Extraction Bodenverbesserungsmittel und Kultursubstrate - Extraktion
d'éléments solubles dans l'eau régale von in Königswasser löslichen Elementen
This European Standard was approved by CEN on 11 August 2001.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13650:2001 E
worldwide for CEN national Members.
Contents
page
Foreword . 3
1 Scope. 4
2 Normative references. 4
3 Terms and definitions . 4
4 Principle . 4
5 Reagents . 5
6 Apparatus. 5
7 Test sample passing through a 500 m sieve. 6
8 Procedure. 6
9 Determination of extracted elements . 7
10 Expression of results. 7
11 Precision . 7
12 Test Report. 7
Annex A (informative) Results of an interlaboratory trial to determine aqua regia soluble
elements. . 9
Annex B (informative) Methods of analysis used in the interlaboratory trial. 16
Bibliography. 17
Foreword
This European Standard has been prepared by Technical Committee CEN/TC 223 "Soil improvers and
growing media", the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by March 2002, and conflicting national standards shall be withdrawn at
the latest by March 2002.
The annexes A and B are informative.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark,
Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal,
Spain, Sweden, Switzerland and the United Kingdom.
SAFETY PRECAUTIONS — Care should be taken when handling samples that may contain sharps or are of
a dusty nature.
1 Scope
This European Standard specifies a method for the routine extraction of aqua regia soluble elements (as listed in
annex B) from soil improvers or growing media. Materials containing more than about 28 % (m/m) organic matter
will require treatment with additional nitric acid. With high solute concentrations in extract solutions, spectral
interference’s and background enhancement should be expected.
The method is not applicable to liming materials and preformed materials such as mineral wool slabs and foam
slabs.
NOTE 1 Aqua regia will not totally dissolve most soil improvers or growing media, and the efficiency of extraction for
particular elements differs from element to element. Such efficiency might also differ for the same element in different matrices.
Elements extractable in aqua regia cannot therefore, be described as “Totals”; conversely they cannot be regarded as the “bio-
available” fraction, as the extraction procedure is too vigorous to represent any biological process.
NOTE 2 The requirements of the standard may differ from the national legal requirements for the declaration of the products
concerned.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies (including amendments).
EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696:1987).
EN 13039, Soil improvers and growing media - Determination of organic matter content and ash.
EN 13040:1999, Soil improvers and growing media - Sample preparation for chemical and physical tests,
determination of dry matter content, moisture content and laboratory compacted bulk density.
3 Terms and definitions
For the purposes of this standard the terms and definitions given in EN 13039 and EN 13040 apply.
4 Principle
The dried sample is finely ground and extracted with a hydrochloric/nitric acid mixture by standing for 16 h at room
temperature, followed by boiling under reflux for 2 h. The extract is clarified and the extracted elements
determined.
The test sample shall be ground to less than 500 m prior to aqua regia digestion. Such grinding is designed to
a) give a more homogeneous sample from which a sub-sample is taken;
b) increase the efficiency of acid attack by increasing the surface area of the particles.
5 Reagents
5.1 General
All reagents used shall be of recognized analytical quality. Use water of grade 2 complying with EN ISO 3696.
Deionized water may be used, providing that it meets the requirements given above. It is recommended that the
same batch of water be used throughout a given batch of determinations and that blank determinations are carried
out.
5.2 Hydrochloric acid, c(HCl) = 12 mol/l; 1,18 g/ml; 37 % mass/volume.
5.3 Nitric acid, c(HNO ) = 15 mol/l; 1,42 g/ml; not less than 65 % mass/volume.
5.4 Nitric acid, c(HNO ) = 0,5 mol/l, 35 ml nitric acid (5.3) is diluted to one litre of water.
6 Apparatus
6.1 General
NOTE It has been found convenient to keep separate sets of glassware including antibumping granules or roughened beads
for the determinations given in annex B, in order to reduce the possibility of within-laboratory contamination.
Clean all new glassware by carefully immersing in warm nitric acid (5.4) for a minimum of 6 h and then rinse in
water.
The apparatus consists of the usual laboratory apparatus, and in particular the following :
6.2 Grinding mill, capable of grinding dried samples to a size less than 500 m without contamination by the
elements to be determined.
A mill causing little or no contamination is essential, as is adequate cleaning between samples to eliminate memory
effects. Both agate and zirconium oxide mills have been found suitable. [5]
6.3 Test sieve, of aperture size 500 m, e.g. test sieve with gauze preferably made from plastic materials, e.g.
nylon.
6.4 Desiccator, of nominal volume 2 l.
6.5 Reaction vessel, of nominal volume of not less than 250 ml.
NOTE 1 It has been found convenient to use for mixing a two-neck Erlenmeyer type reaction vessel of nominal value 500 ml
with ground-glass joints and a drip funnel of nominal value 100 ml with conical ground-glass joints and stopper.
NOTE 2 A larger reaction vessel may be required for samples when a sample weight exceeding 1 g is taken for analyses or
excessive frothing is experienced.
6.6 Reflux condenser, straight-through type, with conical ground-glass joints.
NOTE Water-cooled condensers with a minimum effective length of at least 200 mm have been found suitable. The
effective length is the internal surface, which is in contact with the cooling water. The overall external length of such condensers
is usually at least 363 mm.
6.7 Roughened glass beads, diameter 2 mm to 3 mm (or anti-bumping granules).
6.8 Temperature-controlled heating apparatus, capable of heating the contents of the reaction vessel to reflux
temperature.
6.9 Funnel, of diameter approximately 100 mm.
6.10 Volumetric flask, of nominal capacity 100 ml.
6.11 Filter papers, cellulose-based ashless types, with a medium pore size of approximately 8 m and diameter
of 150 mm.
6.12 Analytical balance, capable of weighing accurately to 1,0 mg.
7 Test sample passing through a 500 m sieve
Take approximately 5 g of the sample prepared in accordance with EN 13040:1999, clause 9, and grind the sub-
sample using a mill (6.2) until all the sub sample has passed through the sieve (6.3).
8 Procedure
8.1 WARNING — Digestions with hydrochloric and nitric acid are potentially hazardous and laboratory
coats, gloves and safety spectacles or goggles shall be used.
The digestion shall be carried out in a well-ventilated fume cupboard with the reflux digestion on a
temperature - controlled heating apparatus. It is essential to add antibumping granules (or roughened
glass beads) both to the blank and the samples to prevent bumping and loss of solution. It is important to
maintain gentle reflux, both of the blank and the test samples, to avoid temperature fluctuations, which
could cause local superheating.
The toxicity or carcinogenicity of each reagent used in this method has not been precisely defined;
however, each chemical compound needs to be treated as a potential health hazard. From this viewpoint,
reduce exposure to these chemicals to the lowest possible level by whatever means available.
Toxic fumes are evolved by nitric acid. Always use the concentrated acid in a fume cupboard.
8.2 Digestion
Weigh approximately 1 g to 3 g, to the nearest 0,001 g, of the finely ground test sample (clause 7) into the reaction
vessel (6.5). Moisten with about 0,5 ml to 1,0 ml water. Add while mixing, 21 ml of hydrochloric acid (5.2) followed
by 7 ml of nitric acid (5.3), drop by drop if necessary to reduce foaming. Allow to stand for 16 h at room temperature
to allow for slow oxidation of the organic matter in the sample.
NOTE 1 It is common practice to add hydrochloric acid directly to the reaction vessel, followed by the nitric acid, and to
assume that the aqua regia forms in the reaction vessel. However, problems have been encountered with materials rich in
carbonates, where a substantial portion of the hydrochloric acid has been consumed before the nitric acid can be added. Under
such circumstances, the correct formation of aqua regia is doubtful.
The amount of aqua regia is sufficient only for oxidation of about 0,85 g of organic matter. If there is any doubt
about the amount of organic matter present, carry out a determination according to EN 13039. If there is more than
0,85 g of organic matter (corresponding to about 0,5 g of organic carbon) in the test sample reduce the quantity of
sample analyzed or proceed as follows.
Allow the first reaction with aqua regia to subside. Then add an extra 1 ml of nitric acid (5.3) only to every 0,17 g of
organic matter above 0,85 g. Do not add more than 10 ml of nitric acid at any time, and allow any reaction to
subside before proceeding further.
Add a few roughened glass beads (6.7) and place the reaction vessel on a cool heating apparatus (6.8). Raise the
temperature of the reaction mixture slowly until reflux conditions are reached and maintain for 2 h ensuring that the
condensation zone is lower than 1/3 of the height of the condenser, then allow to cool.
Transfer the contents of the rea
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