CEN/TR 15314:2006
(Main)Durability of wood and wood-based products - Quantitative determination of quaternary ammonium compounds in wood
Durability of wood and wood-based products - Quantitative determination of quaternary ammonium compounds in wood
This CEN Technical Report specifies a laboratory method of determining the content of quaternary ammonium compounds in commercially QAC-treated wood. The method described has a measurement range up to QAC contents of 1 500 mg/kg of dry matter.
NOTE 1 This method can need some modifications with some wood species such as hardwoods.
NOTE 2 It is applicable to QAC with a molar mass ranging between 200 g/mol and 500 g/mol.
NOTE 3 The method has a quantification limit corresponding to 250 mg of QAC per kilogram of wood expressed as dry matter.
Dauerhaftigkeit von Holz und Holzprodukten - Quantitative Bestimmung von quartären Ammoniumverbindungen in Holz
Durabilité du bois et des matériaux dérivés du bois - Détermination quantitative des composés ammonium quaternaire dans le bois
Le présent Rapport technique CEN spécifie une méthode de laboratoire permettant de déterminer la teneur en composés d'ammonium quaternaire dans le bois traité avec des QAC, disponible dans le commerce. La méthode décrite permet de mesurer jusqu'à des teneurs en QAC de 1 500 mg/kg de matière sèche.
NOTE 1 Des modifications peuvent être apportées à cette méthode en fonction de l'essence de bois comme les bois feuillus.
NOTE 2 Elle s'applique aux QAC dont la masse molaire est comprise entre 200 g/mol et 500 g/mol.
NOTE 3 Cette méthode a une limite de quantification correspondant à 250 mg de QAC par kilogramme de bois exprimé en matière sèche.
Trajnost lesa in lesnih proizvodov – Kvantitativno določevanje kvarternih amonijevih spojin v lesu
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2006
7UDMQRVWOHVDLQOHVQLKSURL]YRGRY±.YDQWLWDWLYQRGRORþHYDQMHNYDUWHUQLK
DPRQLMHYLKVSRMLQYOHVX
Durability of wood and wood-based products - Quantitative determination of quaternary
ammonium compounds in wood
Dauerhaftigkeit von Holz und Holzprodukten - Quantitative Bestimmung von quartären
Ammoniumverbindungen in Holz
Durabilité du bois et des matériaux dérivés du bois - Détermination quantitative des
composés ammonium quaternaire dans le bois
Ta slovenski standard je istoveten z: CEN/TR 15314:2006
ICS:
79.040 Les, hlodovina in žagan les Wood, sawlogs and sawn
timber
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
TECHNICAL REPORT
CEN/TR 15314
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
January 2006
ICS 79.080
English Version
Durability of wood and wood-based products - Quantitative
determination of quaternary ammonium compounds in wood
Durabilité du bois et des matériaux dérivés du bois - Dauerhaftigkeit von Holz und Holzprodukten - Quantitative
Détermination quantitative des composés ammonium Bestimmung von quartären Ammoniumverbindungen in
quaternaire dans le bois Holz
This Technical Report was approved by CEN on 14 December 2005. It has been drawn up by the Technical Committee CEN/TC 38.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, 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
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15314:2006: E
worldwide for CEN national Members.
Contents Page
Foreword .3
Introduction.4
1 Scope .5
2 Normative references .5
3 Safety precautions.5
4 Principle.5
5 Reagents.6
6 Apparatus .7
7 Preparation of the test sample.7
8 Procedure .7
9 Calculation and expression of results.8
10 Quality assurance .9
11 Precision.9
12 Test report .9
Annex A (informative) Ring test results.10
Annex B (informative) Environmental, health and safety precautions within chemical/biological
laboratory .11
Annex C (informative) Determination of the molar mass of the QAC.12
Bibliography.13
Foreword
This Technical Report (CEN/TR 15314:2006) has been prepared by Technical Committee CEN/TC 38
“Durability of wood and wood-based products”, the secretariat of which is held by AFNOR.
Introduction
At present, no standardised method for the analysis of quaternary ammonium compounds (QAC) in wood is
recognised in Europe. Only a few national standards are available world wide, e.g. ASTM D5584-94, AWPA A
16-93 or AWPA A 18-04.
This CEN Technical Report has been issued in order to facilitate the analysis of QAC-treated wood.
1 Scope
This CEN Technical Report specifies a laboratory method of determining the content of quaternary ammonium
compounds in commercially QAC-treated wood. The method described has a measurement range up to QAC
contents of 1 500 mg/kg of dry matter.
NOTE 1 This method may need some modifications with some wood species such as hardwoods.
NOTE 2 It is applicable to QAC with a molar mass ranging between 200 g/mol and 500 g/mol.
NOTE 3 The method has a quantification limit corresponding to 250 mg of QAC per kilogram of wood expressed as dry
matter.
2 Normative references
The following referenced documents are indispensable for the application of this CEN Technical Report. For
dated references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 322, Wood-based panel — Determination of moisture content
EN ISO 1042, Laboratory glassware — One-mark volumetric flasks (ISO 1042:1998)
EN ISO 2871-2:1994, Surface active agents — Detergents — Determination of cationic-active matter content
— Part 2: Cationic active matter of low molecular mass (between 200 and 500) (ISO 2871-2:1990)
EN ISO 3696, Water for analytical laboratory use — Specification and test methods (ISO 3696:1987)
EN ISO 4788, Laboratory glassware —Graduated measuring cylinders (ISO 4788:2005)
ISO 385-1, Laboratory glassware — Burettes — Part 1: General requirements
ISO 648, Laboratory glassware —One-mark pipettes
ISO 835-2, Laboratory glassware — Graduated pipettes — Part 2: Pipettes for which no waiting time is
specified
3 Safety precautions
Persons using this method shall be familiar with normal analytical laboratory procedures and practice.
This method does not purport to address all the safety problems, if any, associated with its use.
It is the responsibility of the user to establish health and safety practices and to ensure compliance with any.
European or national regulatory conditions (also see Annex B for environmental, health and safety
precautions) shall be taken into account.
4 Principle
The quaternary ammonium compound is extracted from the wood material using a mixture of methanol and
hydrochloric acid in an ultrasonic bath.
The quaternary ammonium compound (cationic substance) is quantified by titration with an anionic surface
active agent standard solution (sodium dodecyl sulfate) containing a mixture of a cationic and an anionic dye.
The titration is performed in a 2-phase system consisting of water and trichloromethane according to
EN ISO 2871-2. Cationic substances and the anionic dye (disulphine blue VN 150) constitute a salt which is
soluble in trichloromethane and results in a blue colour.
The anionic dye in the salt is replaced gradually by the anionic surface active agent during the titration
process leading to a discoloration of the organic phase at equivalence point. At the same time the disulphine
blue moves into the water.
NOTE 1 Cationic surface active agents as well as other disulphine blue active substances will also react with the titrant
and be determined as QAC.
NOTE 2 In order to determine the mass of QAC its molar mass is required.
5 Reagents
During the analysis, unless, otherwise specified, use only reagents of recognised analytical grade that have
been checked in advance as to not interfere with the analytical results, and water complying with grade 3 as
defined in EN ISO 3696.
5.1 Trichloromethane (CAS 67-66-3) (CHCl ).
5.2 Methanol (CH OH).
NOTE Other solvents may be used instead of methanol as some extraction difficulties can occur with some wood
species (e.g. hardwoods). It is recommended to cross check the extraction efficiency of any other solvent or solvent
mixture with that of methanol / hydrochloric acid used.
5.3 Dimidiumbromide (CAS 518-67-2) (C H BrN ).
20 18 3
5.4 Disulphine blue VN 150 (CAS 129-17-9) (C H N S O Na).
27 31 2 2 6
5.5 Sodium dodecyl sulfate for analysis of surface active agents (CAS 151-21-3) (C H SO Na).
12 25 4
5.6 Hydrochloric acid solution, c(HCl) = 1 mol/l.
Dilute 9 ml of concentrated hydrochloric acid (ρ 20 = 1,18 g/ml) to 100 ml with water.
NOTE Test ampoules containing a definite amount may be used for the preparation of the hydrochloric acid solution
instead of concentrated hydrochloric acid.
5.7 Ethanol, (C H OH) aqueous solution volume fraction 10 %.
2 5
Add 30 ml of ethanol to 270 ml of water and mix well.
5.8 Sulfuric acid, solution c(H SO )= 2,5 mol/l.
2 4
20 = 1,84 g/ml) to about 80 ml of
Cautiously add, with stirring and cooling, 14 ml of concentrated sulfuric acid (ρ
water and dilute to 100 ml with water.
NOTE Test ampoules containing a definite amount may be used for the preparation of the sulfuric acid solution
instead of concentrated sulfuric acid.
6 Apparatus
Ordinary laboratory apparatus and the following.
NOTE Glassware should be thoroughly cleaned prior to use by means of ethanol.
6.1 Analytical balance, accurate to 0,1 mg.
6.2 Ultra-sonic bath.
6.3 Volumetric glassware, of class A quality in accordance with ISO 385-1 for the burettes, ISO 835-2
and ISO 648 for the pipettes, EN ISO 4788 for the measuring cylinders and EN ISO 1042 for the volumetric
flasks. The burette shall be 10 ml graduated in 0,02 ml.
6.4 Conical flasks with glass stopper, 100 ml capacity.
6.5 Polytetrafluoroethylene (PTFE) filter, porosity 0,45 µm (e.g. combined with a syringe).
6.6 Variable dispenser (5ml to 30ml).
7 Preparation of the test sample
Collect at least 20 g of the sample material taken according to e.g. EN 212. This sample material is preferably
ground under mild conditions to a powder with a particle size of less than 0,5 mm diameter.
Homogenise the ground material to obtain a representative sample, and store it in a brown glass bottle with
screw caps with a polytetrafluoroethylene (PTFE) insert. This is the test sample.
8 Procedure
8.1 General
It is recommended to carry out at least two parallel analyses. If the results differ by more than 10 % an
additional analysis shall be made.
8.2 Standard solutions
8.2.1 Sodium dodecyl sulfate solution
Dissolve 1,442 g sodium dodecyl sulfate (5.5) in water into a 1 000 ml volumetric flask (6.3) resulting in a
concentration of 0,005 mol/l.
NOTE The purity of the sodium dodecyl sulfate may be determined by the method given in 4.2.1 of EN ISO 2871-
2:1994.
8.2.2 Indicator solution
Weigh (500 ± 5) mg dimidiumbromide (5.3) into a 100 ml beaker and dissolve it in 30 ml hot aqueous ethanol
(5.7). Then weigh (250 ± 5) mg disulphine blue VN 150 (5.4) into a 100 ml beaker and dissolve it in 30 ml hot
aqueous ethanol (5.7). After cooling, transfer both solutions quantitatively into a 250 ml volumetric flask and
make up to the mark with aqueous ethanol. Transfer 20 ml of this solution into a 500 ml volumetric flask which
already contains approximately 200 ml water. Finally add 20 ml of 2,5 mol/l sulfuric acid (5.8) and make up to
the mark with water.
NOTE The indicator solution should be stored in the dark.
8.3 Determination of the QAC content in treated timber
8.3.1 Extraction
From the prepared timber sample (Clause 7), remove a small portion of this sample (0,5 ± 0,05) g and
determine its moisture content according to EN 322; record the value obtained.
Depending on the expected QAC content, transfer 5 g to 10 g of the test sample (7) to a flask of known mass
(m ) and reweigh the flask and contents (m ). Calculate the mass of the test sample (m = m – m ) and add,
1 2 3 2 1
to the nearest 0,5 ml, 7,0 times m ml of methanol and, to the nearest 0,05 ml, 0,1 times m ml of the
3 3
hydrochloric acid (5.6).
NOTE 1 A 100 ml flask is suitable for test samples of 10 g.
Place the hydrochloric acidic suspension in an ultrasonic bath (6.2) and agitate it for 1 h. Allow the warm
suspension to cool at room temperature, weigh and add methanol to give a total extract mass of 7,50 times m
(total mass of flask and contents is m + 8,5 times m ), to the nearest 0,1 g; record the total mass as m .
1 3 4
Stopper the flask, swirl the contents vigorously and store to clear over night (at least 12 h). Remove a part of
the clear solution and filter by means of a 0,45 µm PTFE-filter (6.5). Use 10 g to 30 g of the filtered solution for
the quantitative determination of QAC depending on the expected concentration.
NOTE 2 Since a complete extraction is essential for a successful analysis, treated timber with a known QAC content
should be analysed in parallel.
8.3.2 Sample analysis
Depending on the expected QAC concentration transfer up to 30 g of the
...
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