ISO 11263:1994

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Kakovost tal - Ugotavljanje fosforja - Spektrometrijsko ugotavljanje fosforja, topnega v raztopini natrijevega hidrogen karbonataQualité du sol -- Dosage du phosphore -- Dosage spectrométrique du phosphore soluble dans une solution d'hydrogénocarbonate de sodiumSoil quality -- Determination of phosphorus -- Spectrometric determination of phosphorus soluble in sodium hydrogen carbonate solution13.080.10Chemical characteristics of soilsICS:Ta slovenski standard je istoveten z:ISO 11263:1994SIST ISO 11263:1996en01-oktober-1996SIST ISO 11263:1996SLOVENSKI
STANDARD
INTERNATIONAL STANDARD ISO 11263 First edition 1994-12-01 Soil quality - Determination of hosphorus - Spectrometric etermination of phosphorus soluble in sodium hydrogen carbonate solution QuaM du so/ - Dosage du Phosphore - Dosage spectrom&rique du Phosphore soluble dans une solutjon d’hydogenocarbonate de sodium Reference number ISO 11263:1994(E) SIST ISO 11263:1996

INTERNATIONAL STANDARD 0 ISO ISO 11263:1994(E) Soil quality - Determination of phosphorus - Spectrometric determination of phosphorus soluble in sodium hydrogen carbonate Solution 1 Scope This International Standard specifies an extraction method and analytical conditions to determine the content of soil phosphorus soluble in sodium hydro- gen carbonate Solution. After the extraction Step, two different methods of colour development are poss- ible. Subclause 4.2 specifies colour development at room temperature. Subclause 4.3 specifies colour development after heating to a high temperature. This International Standard is applicable to all types of soils. 2 Normative references The following Standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi- cation, the editions indicated were valid. All Standards are subject to revision, and Parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most re- cent editions of the Standards indicated below. Members of IEC and ISO maintain registers of cur- rently valid International Standards. ISO 3696: 1987, Water for analytical laboratory use - Specifica tjon and test methods. ISO 11464: 1994, Seil quality - Pretreatment of sam- ples for physico-Chemical analyses. ISO 11465:1993, Seil quality - Determination of dry matter and water content on a mass basis - Gravimetric method. 3 Principle A soil, pretreated according to ISO 11464, is treated with a 0,5 mol/1 sodium hydrogen carbonate Solution at pH 8,50 to reduce the concentration of Calcium, aluminium and iron(lll) ions by precipitation of Calcium carbonate and aluminium and iron(lll) hydroxides and to release Phosphate ions into Solution. The clear extract is analysed for phosphorus by a spectrometric method involving the formation of an antimony-Phosphate-molybdate complex (at room temperature, 4.2) or a Phosphate-molybdate complex (at a high temperature, 4.3) both reduced with ascorbic acid to form a deep-coloured, blue complex. 4 Reagents All reagents shall be of recognized analytical grade. Use water complying with grade 2 of ISO 3696. 4.1 Reagents used in both colour developments 4.1 .l Sodium hydroxide solution, c(NaOH) = 1 mol/l. Dissolve 40,O g r_t 0,4 g of sodium hydroxide (NaOH) pellets in water. Cool and dilute to 1 000 ml with water. Store in an inert and hermetically sealed bottle. 4.12 Extracting solution. Dissolve 42,0 g + 0,l g of sodium hydrogen carbon- ate (NaHCO,) in-800 ml of water. Adjust the pH to 8,50 & 0,02 with sodium hydroxide Solution (4.1 .l). Transfer the Solution into a 1 000 ml volumetric flask and make up to the mark with water. NOTE 1 This reagent shall be used within 4 h of prep- aration. SIST ISO 11263:1996
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