EN 13652-2001 pdf download.Soil improvers and growing media-Extraction of water soluble nutrients and elements.
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 ot 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 impmvers 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
A sample is extracted with water at 22 °C ± 3 C in an extraction volume ratio of 1 + 5. The extracted nutrients are determined by various methods as appropriate.
5 Reagents
5.1 General
All reagents used shall be of recognised analytical quality and water of grade 2 according to EN ISO 3696.
5.2 Nitric acid, c(HNO3) = 15 mol/1; p 1,42 g/ml: not less than 65% mass/volume.
5.3 Nitric acid, c(HNO3) 0,5 mol/l, 35 ml nitric acid (5.2) dilute required volume of nitric acid (5.2) with water.
6.1 General
NOTE It has been found convenient to keep separate sets of glassware for the determinations given in annex B, in order to reduce the possibdity of within-laboratory contamination.
All glass apparatus and plastic vessels used in the procedure should be subject to an appropriate preparation procedure in order to keep the risk of contamination to a minimum. It is recommended that all vessels (glass and plastic) are cleansed by carefully immersing in warm nitric acid (5.3) for a minimum of 6 h and then rinsed in water.
Borosilicate glassware shall not be used if boron is to be determined.
Rubber stoppers, which may contain traces of metals shall not be used. It is recommended to use plastic or any other stopper free of all substances to be analyzed.
The apparatus consists of the usual laboratory apparatus, and in particular the following:
6.2 Analytical balance with an accuracy of 10 mg.
6.3 PlastIc bottles or containers, sufficiently large (500 ml to 1500 ml) with screw cap to accommodate the volume of the sample, extractant and at least 10 % air volume.
6.4 Shaking or mixing machine, capable of holding the plastic bottles or containers (6.3) and maintaining the sample in suspension without damaging the structure of the sample. The use of a horizontal table shaker is recommended.
6.5 Filter paper, cellulose-based ashless types, with a medium pore size of approximately 8 m and diameter of 150 mm.
NOTE Centrifugation is an acceptab’e alternative.
7 Test sample
Prepare the laboratory sample in accordance with EN 13040:1999, clause 8. and determine the laboratory compacted bulk density in accordance with EN 13040:1999, annex A.
8 Procedure
8.1 Extraction
8.1.1 Test samples passing through a 20 mm sieve
Take a weight equivalent to 60 ml of the sample (EN 13040:1999, clause 8.5) volume to the nearest 1 g and transfer to the container (6.3). Add 300 ml of water, secure the cap and shake for 1 h on the shaking machine (6.4) at 22 °C ± 3 °C.
8.1.2 Test samples passing through a 40 mm sieve
Take a weight equivalent to 250 ml of the sample (EN 13040:1999, clause 8.3) volume to the nearest 1 g and transfer to the container (6.3). Add 1250 ml of water, secure the cap and shake for 1 h on the shaking machine (6.4) at 22 °C ± 3 °C.
EN 13652:2001 (E)
8.1.3 Filtration
Filter through filter paper (6.5) discarding at least the first 10 ml. In some cases paper filtration is too slow or even impossible. In such cases alternative procedures for obtaining a clear supernatant are acceptable and the technique used shall be reported.
The filtered extract is stable for three days in a hermetically closed polyethylene bottle if stored in a refrigerator at 0 cC to 5 °C. The filtrate can be stored for longer periods in a deep freezer at about – 18 °C.
Before using a solution that has been frozen, the thawed solution shall be thoroughly mixed to eliminate gradient separation that occurs on freezing and subsequent thawing.
8.2 Blank
The reagent blank test shall be carried out in parallel with the determination, by the same procedure as outlined in 8.1.1 or 8.1.2 and 8.1.3, using the same quantities of all the reagents as in the determination but omitting the test portion.
NOTE The measurement of a blank is introduced to determine the contribution of the extracting solution, glassware and filter paper used.EN 13652-2001 pdf download.