EN ISO 3946:1994
(Main)Starches and derived products - Determination of total phosphorus content - Spectrophotometric method (ISO 3946:1982)
Starches and derived products - Determination of total phosphorus content - Spectrophotometric method (ISO 3946:1982)
Destruction of the organic substances by digestion with a sulpho-nitric mixture and conversion of phosphates to orthophosphates. Formation of a phosphomolybdate. Measurement of the intensity of the blue colour at a wavelength of 825 nm. The method applies to contents up to 5 % (m/m).
Stärke und Stärkederivate - Bestimmung des Gesamtphosphorgehaltes - Spektralphotometrisches Verfahren (ISO 3946:1982)
Diese Internationale Norm legt ein spektralphotometrisches Verfahren zur Bestimmung des Gesamtphosphorgehalts von Stärke, einschliesslich Derivate und Nebenprodukte, fest, deren als Phosphor (P) berechneter, erwarteter Massenanteil 5% nicht überschreitet.
Amidons, fécules et produits dérivés - Détermination de la teneur en phosphore total - Méthode spectrophotométrique (ISO 3946:1982)
La présente Norme internationale spécifie une méthode de détermination de la teneur en phosphore total des amidons, fécules et produits dérivés, dont la teneur escomptée est inférieure à 5 % (m/m) en phosphore (P).
Škrobi in škrobni derivati - Določevanje celotnega fosforja - Spektrofotometrijska metoda (ISO 3946:1982)
General Information
- Status
- Published
- Publication Date
- 24-Aug-1994
- Withdrawal Date
- 27-Feb-1995
- Technical Committee
- CEN/SS C10 - Starch
- Drafting Committee
- CEN/SS C10 - Starch
- Current Stage
- 9093 - Decision to confirm - Review Enquiry
- Start Date
- 13-Oct-1999
- Completion Date
- 13-Oct-1999
Overview
EN ISO 3946:1994 specifies a spectrophotometric method for the determination of the total phosphorus content in starches and derived products. Applicable to samples containing phosphorus up to 5% by mass, this international standard outlines a precise analytical procedure widely used in laboratories to ensure quality control and compliance in starch processing industries. The method involves the digestion of organic substances followed by the formation and measurement of phosphomolybdate complexes, which produce a characteristic blue color measurable at 825 nm wavelength.
Key Topics
Scope and Applicability: The standard is designed for starches, their derivatives, and related by-products, focusing on total phosphorus content expressed as mass percentage (m/m) not exceeding 5%.
Analytical Principle:
- Destruction of organic substances through digestion with a sulpho-nitric acid mixture.
- Conversion of all phosphate compounds to orthophosphates.
- Formation of a phosphomolybdate complex, which is reduced to molybdenum blue.
- Measurement of the intensity of the blue color at 825 nm using a spectrophotometer to quantify phosphorus concentration.
Reagents and Solutions:
- Sulpho-nitric reagent (sulfuric acid + nitric acid).
- Ammonium molybdate solution.
- Ascorbic acid as a reducing agent.
- Standard solutions prepared from potassium dihydrogenorthophosphate for calibration.
Equipment Requirements: Standard laboratory apparatus, including volumetric flasks, pipettes, and spectrophotometers capable of readings at 825 nm wavelength, adhering to ISO 1042 specifications for volumetric glassware.
Calculation and Repeatability:
- Results expressed as a percentage of phosphorus by mass.
- Protocol includes detailed formulas for calculating phosphorus content from absorbance values.
- Method emphasizes repeatability criteria, ensuring accuracy with a maximum allowable difference of ±2% for phosphorus contents above 0.2%.
Applications
This spectrophotometric method provided by EN ISO 3946:1994 is critical for:
- Quality Control: Ensuring consistent phosphorus content in starch production, which affects functional properties and regulatory compliance.
- Research and Development: Formulating starch derivatives and blended products with precise phosphorus levels.
- Regulatory Testing: Meeting international standards for food additives and industrial starch products.
- Industrial Processing: Monitoring raw materials and final products in starch manufacturing to optimize processing parameters.
The method is particularly suited for analytical laboratories involved in starch chemistry and related food and industrial applications where accurate phosphorus quantification is essential.
Related Standards
- ISO 1042 – Laboratory glassware: volumetric flasks.
- EN ISO 9001 – Quality Management Systems applicable for laboratories following standardized testing procedures.
- Other relevant ISO standards in food chemistry and phosphorus determination methods.
By adhering to EN ISO 3946:1994, organizations ensure reliable phosphorus content measurement aligned with international best practices, facilitating compliance and enhancing product quality across starch and derivative product industries.
Frequently Asked Questions
EN ISO 3946:1994 is a standard published by the European Committee for Standardization (CEN). Its full title is "Starches and derived products - Determination of total phosphorus content - Spectrophotometric method (ISO 3946:1982)". This standard covers: Destruction of the organic substances by digestion with a sulpho-nitric mixture and conversion of phosphates to orthophosphates. Formation of a phosphomolybdate. Measurement of the intensity of the blue colour at a wavelength of 825 nm. The method applies to contents up to 5 % (m/m).
Destruction of the organic substances by digestion with a sulpho-nitric mixture and conversion of phosphates to orthophosphates. Formation of a phosphomolybdate. Measurement of the intensity of the blue colour at a wavelength of 825 nm. The method applies to contents up to 5 % (m/m).
EN ISO 3946:1994 is classified under the following ICS (International Classification for Standards) categories: 67.180.20 - Starch and derived products. The ICS classification helps identify the subject area and facilitates finding related standards.
EN ISO 3946:1994 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-1998
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Starches and derived products - Determination of total phosphorus content -
Spectrophotometric method (ISO 3946:1982)
Stärke und Stärkederivate - Bestimmung des Gesamtphosphorgehaltes -
Spektralphotometrisches Verfahren (ISO 3946:1982)
Amidons, fécules et produits dérivés - Détermination de la teneur en phosphore total -
Méthode spectrophotométrique (ISO 3946:1982)
Ta slovenski standard je istoveten z: EN ISO 3946:1994
ICS:
67.180.20 Škrob in izdelki iz njega Starch and derived products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
International Standard
INTERNATIONAL ORGANIZATION FOR STANDARDIZATIONWEIKJJYHAPOAHAR OPTAHM3AWlR fl0 CTAH~APTM3AWlM~RGANISATION INTERNATIONALE DE NORMALISATION
Starches and derived products - Determination of total
Spectrophotometric method
phosphorus content -
Amidons, fkcules et produirs d&iv& - Determination de Ia teneur en Phosphore total - Mkthode spectrophotometrique
First edition - 1982-12-01
UDC 664.2 : 543.847 Ref. No. ISO 3946-1982 (EI
Descriptors : starches, Chemical analysis, determination of content, phosphorus, spectrophotometric analysis.
Price based on 3 pages
Foreword
BS0 (the international Organization for Standardization) is a wsrldwide federation of
national Standards institutes (60 member bedies). The werk of developing Inter-
national Standards is carried out through ISO technical committees. Every member
body interested in a subject for which a technical committee has been set up has the
right ts be represented on that csmmittee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work.
Draft International Standards adopted by the technical committees are circulated to
the member bodies for apprsval before their acceptance as International Standards by
the ISO Council.
International Standard ISO 3946 was developed by Technical Committee ISO/TC 93,
Starch fincluding derivatives and Qy-productsl, and was circulated to the member
bodies in February 1982.
lt has been approved by the member bodies of the following countries :
Austria
Netherlands USA
Egypt, Arab Rep. of Roland
USSR
France
Portugal
Germany, F. R. South Africa, Rep. sf
No member body expressed disapproval of the document.
@ International Organization for Standardization, 1982 0
Printed in Switzerland
INTERNATIONAL STANDARD
ISO 3946-1982 (E)
Starches and derived products - Determination of total
phosphorus content - Spectrophotometric method
4.4 Ammonium molybdate Solution, prepared as follows.
1 Scope and field of application
This International Standard specifies a spectrophotometric In a 1 I flask, dissolve 10,6 g of ammonium molybdate
tetrahydrate [(NH&Mo70~+4H201 in 500 ml of water.
method for the determination of the total phosphorus content
of starch, including derivatives and by-products, in which the
expected content, calculated as phosphorus (P), does not Add 500 ml of 10 mol/1 sulphuric acid Solution, mix and allow
to cool to ambient temperature.
exceed 5 % (mlm).
Sodium hydroxide, 10 mol/1 Solution.
4.5
2 Definition
46 . Phosphorus, Standard solutions.
total phosphorus content : The quantity of phosphorus
determined in accordance with the conditions specified in this
4.6.1 Stock Solution, corresponding to 100 mg of P per litre.
International Standard and expressed as phosphorus (P) as a
percentage by mass of the product as received.
Weigh, to the nearest 0,5 mg, 0,439 3 g of anhydrous
potassium dihydrogenorthophosphate and dissolve in water.
Transfer quantitatively into a 1 000 ml one-mark volumetric
flask.
3 Principle
Dilute to the mark with water and mix.
Destruction of the organic substances by digestion with a
sulpho-nitric mixture and conversion of Phosphates to ortho-
1 ml of this Standard Solution contains 100 pg of P.
Phosphates.
NOTE - The potassium dihydrogenorthophosphate shall be dried
Formation,
...
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