Plastics - Phenol-formaldehyde mouldings - Determination of free ammonia and ammonium compounds - Colorimetric comparison method (ISO 120:1977)

Specification of a semi-quantitative method. The content of free ammonia in a moulded article is of importance, when corrosion of metal inserts or contamination in contact with the article has to be considered. Distillation of the aqueous extract from a powdered test portion, coloration of the distillate by reaction with Nessler reagent and comparison of the colour with that of standard matching solutions.

Kunststoffe - Phenoplast-Formteile - Bestimmung von freiem Ammoniak und Ammoniumverbindungen - Colorimetrisches Vergleichsverfahren (ISO 120:1977)

Diese Internationale Norm beschreibt eine colorimetrische Vergleichsmethode für die halbquantitive Bestimmung des Gehaltes an Ammoniak in Phenoplast-Formteilen. ANMERKUNG: Diese Internationale Norm liefert keinen Absolutwert des vorhandenen Ammoniaks. Der Gehalt an Ammoniak in einem Formteil ist die Bedeutung, wenn mit der Korrosion von Metallteilen oder der Verunreinigung von Lebensmitteln im Kontakt mit dem Teil gerechnet werden muß.

Plastiques - Pièces moulées à base de phénoplastes - Dosage de l'ammoniac libre et des composés ammoniacaux - Méthode par comparaison colorimétrique (ISO 120:1977)

Polimerni materiali - Fenol-formaldehidni oblikovanci - Določevanje prostega amoniaka in amonijevih spojin - Kolorimetrična primerjalna metoda (ISO 120:1977)

General Information

Status
Published
Publication Date
21-Jul-1998
Withdrawal Date
30-Jan-1999
ICS
83.080.10 - Thermosetting materials
Technical Committee
CEN/TC 249 - Plastics
Drafting Committee
CEN/TC 249/SC 1/WG 13 - Thermosets
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Start Date
22-Jul-1998
Completion Date
22-Jul-1998
Ref Project
SIST EN ISO 120:2000 - Plastics - Phenol-formaldehyde mouldings - Determination of free ammonia and ammonium compounds - Colorimetric comparison method (ISO 120:1977)

Overview

EN ISO 120:1998 is an international standard developed by CEN and ISO focusing on the semi-quantitative determination of free ammonia and ammonium compounds in phenol-formaldehyde mouldings. This standard specifies a colorimetric comparison method based on the reaction of ammonia with Nessler reagent. The procedure involves hot aqueous extraction, distillation, and visual comparison of the resulting color to standard matching solutions.

The measurement of free ammonia content in phenol-formaldehyde moulded plastics is critical for applications where corrosion of metal inserts or contamination of food-contact materials might occur. By providing a reliable test method, this standard assists manufacturers and quality control laboratories in maintaining product safety and performance.

Key Topics

  • Scope: Semi-quantitative colorimetric method for detecting free ammonia in phenol-formaldehyde mouldings.
  • Test Principle:
    • Extraction of ammonia from powdered sample with hot water.
    • Distillation of the extract in the presence of oxidizing and alkaline agents.
    • Color development with Nessler reagent.
    • Visual comparison against standard ammonia solutions.
  • Sample Preparation: Grinding or milling the moulding to a fine powder passing through a 250 μm sieve.
  • Reagents Used:
    • Potassium permanganate as oxidizing agent.
    • Sodium hydroxide solution for alkalinity.
    • Nessler reagent for colorimetric detection.
    • Ammonia-free distilled water to avoid contamination.
  • Apparatus Required: Laboratory glassware, distillation setup, balances, pipettes, filter funnel, and Nessler cylinders.
  • Calculation: The amount of ammonia is expressed as a percentage by mass using a formula incorporating the color comparison results and dilution factors.
  • Result Expression: Semi-quantitative results are presented based on color matching with prepared standard solutions ranging from 0.01 mg to 0.06 mg ammonia.

Applications

  • Quality Control in Plastic Manufacturing: Ensures phenol-formaldehyde mouldings meet safety criteria by monitoring residual free ammonia.
  • Corrosion Prevention: Identifies articles containing ammonia levels that could compromise metal components embedded within mouldings.
  • Food Industry Safety: Assesses risk of ammonia contamination from packaging or contact materials, ensuring compliance with hygiene standards.
  • Research and Development: Supports formulation improvements and new product development by analyzing the chemical stability of thermoset plastics.
  • Regulatory Compliance: Assists manufacturers in fulfilling regulatory requirements for chemical content in thermoset resin products.

Related Standards

  • ISO 565: Specifications for test sieves used in sample preparation.
  • ISO 648: Laboratory glassware standards, especially for pipettes employed in the quantitative analyses.
  • ISO/TC 61: Technical committee responsible for plastics standards, under which EN ISO 120 falls.
  • Other standards addressing ammonia content measurement in plastics or related materials may complement EN ISO 120 for broader analytical coverage.

By adhering to EN ISO 120:1998, professionals in the plastics and chemical testing fields can perform consistent and reliable assessments of free ammonia levels in phenol-formaldehyde mouldings, enabling safer product design and usage. The method’s straightforward colorimetric approach makes it accessible to standard analytical laboratories with minimal specialized equipment.

Frequently Asked Questions

EN ISO 120:1998 is a standard published by the European Committee for Standardization (CEN). Its full title is "Plastics - Phenol-formaldehyde mouldings - Determination of free ammonia and ammonium compounds - Colorimetric comparison method (ISO 120:1977)". This standard covers: Specification of a semi-quantitative method. The content of free ammonia in a moulded article is of importance, when corrosion of metal inserts or contamination in contact with the article has to be considered. Distillation of the aqueous extract from a powdered test portion, coloration of the distillate by reaction with Nessler reagent and comparison of the colour with that of standard matching solutions.

Specification of a semi-quantitative method. The content of free ammonia in a moulded article is of importance, when corrosion of metal inserts or contamination in contact with the article has to be considered. Distillation of the aqueous extract from a powdered test portion, coloration of the distillate by reaction with Nessler reagent and comparison of the colour with that of standard matching solutions.

EN ISO 120:1998 is classified under the following ICS (International Classification for Standards) categories: 83.080.10 - Thermosetting materials. The ICS classification helps identify the subject area and facilitates finding related standards.

EN ISO 120:1998 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-maj-2000
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DPRQLDNDLQDPRQLMHYLKVSRMLQ.RORULPHWULþQDSULPHUMDOQDPHWRGD ,62
Plastics - Phenol-formaldehyde mouldings - Determination of free ammonia and
ammonium compounds - Colorimetric comparison method (ISO 120:1977)
Kunststoffe - Phenoplast-Formteile - Bestimmung von freiem Ammoniak und
Ammoniumverbindungen - Colorimetrisches Vergleichsverfahren (ISO 120:1977)
Plastiques - Pieces moulées a base de phénoplastes - Dosage de l'ammoniac libre et
des composés ammoniacaux - Méthode par comparaison colorimétrique (ISO 120:1977)
Ta slovenski standard je istoveten z: EN ISO 120:1998
ICS:
83.080.10 Duromeri Thermosetting materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

INTERNATIONAL STANDARD
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION l MEXAYHAPOAHAII OPTAHM3AUW5I I-IO CTAHAAPTW3A~WW.ORGANISATION INTERNATIONALE DE NORMALISATION
Plastics - Phenol-formaldehyde mouldings - Determination
of free ammonia and ammonium compounds - Colorimetric
comparison method
Plastiques - Pikes moulkes 2 base de phenoptastes - Dosage de lfammoniac libre et des composk
ammoniacaux - ASthode par comparaison colorimetrique
First edition - 1977-10-01
UDC 678.632 : (546.171.1 + 547.298.1) : 543.8 Ref. No. ISO 120-1977 (E)
Descriptors : plastics, Phenol formaldehyde resins, mouldings, chemical analysis, determination of content, ammonia, colorimetric analysis,
comparison analysis.
Price based on 2 pages
FOREWORD
ISO (the International Organization for Standardization) is a worldwide federation
of national Standards institutes (ISO member bodies). The work of developing
International 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 to be represented on that committee. 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 approval before their acceptance as International
Standards by the ISO Council.
International Standard ISO 120 was developed by Technical Committee lSO/TC 61,
Plastics, and was circulated to the member bodies in October 1975.
lt has been approved by the member bodies of the following countries :
Austral ia Iran South Africa, Rep. of
Austria
Israel Spain
Belgium Italy Sweden
Brazil Japan Switzerland
Czechoslovakia Mexico Turkey
Finland Netherlands United Kingdom
France New Zealand U.S.A.
Germany Peru U.S.S. R.
Hungary Poland Yugoslavia
India Romania
No member body expressed disapproval of the document.
This International Standard cancels and replaces ISO Recommendation R 120-1959,
of which it constitutes a technical revision.
0 International Organkation for Standardization, 1977 e
Printed in Switzerland
ISO 120-1977 (E)
INTERNATIONAL STANDARD
Plastics - Phenol-formaldehyde mouldings - Determination
of free ammonia and ammonium compounds - Colorimetric
comparison method
5 APPARATUS
1 SCOPE AND FIELD OF APPLICATION
Ordinary laboratory apparatus, and
This International Standard specifies a colorimetric
comparison method for the semi-quantitative determination
of the amount of ammonia in Phenol-formaldehyde
5.1 Means for reducing the mouldings to a powder.
mouldings.
5.2 Sieve, with nominal apertures of 250 ,um, conform-
NOTE - This International Standard does not provide an absolute
ing to ISO 565.
measure of the ammonia present.
The amount of ammonia in a moulded article is of
5.3 Balance, accurate to 0,Ol g.
importante when corrosion of metal inserts or contami-
nation of foodstuffs in contact with the article has to be
5.4 Glas+stoppered flask, 250 ml capacity.
considered.
5.5 Distillation apparatus, comprising a flask of 250 ml
capacity, splash head and a condenser.
2 REFERENCES
ISO 565, Test sieves - Woven me tal wire clo th and
5.6 Filter funnel, with hardened medium Speed filter
perfora ted pla te - Nominal sizes of apertures.
Paper.
ISO
...

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