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Analysis of tebuconazole in wood treated with Tanalith™ E
1999 - IRG/WP 99-20158
A simple gas chromatographic method for determining tebuconazole in Tanalith™ E treated wood is described. A two step sequential extraction procedure with methanol was used. Sample extracts were analysed without cleanup or concentration using capillary column GC with thermionic specific detection. The performance of the method was assessed using radiata pine (Pinus radiata) sapwood, radiata pine heartwood, and spotted gum (Corymbia citriodora) sapwood as substrates. Recoveries from fortified samples ranged from 97% to 103%. The precision of the method was assessed by analysing a number of actual treated wood samples over a range of retention levels, which produced relative standard deviations in the range of 3% to 8%.
D E Ferlazzo


An investigation into the stability of TBTO in LOSP-treated radiata pine
1987 - IRG/WP 3459
Nuclear magnetic resonance (NMR) spectroscopy and reverse phase paper chromatography were used to characterise the organotin compounds found in radiata pine treated with bis (tri-n-butyl) tin oxide (TBTO). Preliminary results indicate that the preservative is remarkably unstable in wood after light organic solvent preservative (LOSP) treatment. Significant decomposition of TBTO occurs in a matter of hours. White crystalline material observed on the surface of treated wood was identified as tributyltin acetate (TBTA). Other tributyltin esters, dibutyltin ethers, and butyltin chlorides were also identified.
K J Archer, R Meder


An evaluation of the potential of ion mobility spectrometry for detection of organic wood preservative components in solutions and treated wood
1994 - IRG/WP 94-20038
For the disposal of wood waste under ecological sound conditions information about its hazardous potential is required. Until now, no highly sensitive rapid analytical methods are available for the detection of wood preservatives under industrial process conditions. Preliminary experiments showed that Ion Mobility Spectrometry (IMS) could be a promising method for rapid detection of organic preservatives in waste wood. A number of organic wood preservatives (i.e. Al-HDO, Quat, Armoblen, Azaconzole, HCH, Creosote, DCFN, Furmecylox, MBT, Methyl-parathion, PCP, Permethrin, K-o-PP, TBTO, TCMTB and Tebuconazole) was studied. Both solutions and treated wood samples were analyzed with IMS. IMS-spectra are generated by analyzing the ionized volatile compounds of the samples. The time each ion needs to proceed to a detector is specific and can be characterized by a comparable Ko value, the so-called reduced mobility constant. A 'fingerprint' of the wood and the chemicals is obtained. IMS was able to distinguish between most of the preservatives. However, in wood, some of the chemicals could not be determined. So far the results are provisional and further investigation is needed.
A Voss, J N R Ruddick, W J Homan, H Militz, H Willeitner


Biocidal screening method of wood extractives by a direct use of cellulose TLC plate
2001 - IRG/WP 01-20226
Most of the methods to evaluate the biological durability of woods have focused on decay fungi and termite as deteriorating organisms and it is well known that one of the most important factors affecting the biological characteristics of wood is extractives. Bioassays for evaluating the biological activities of wood extractives have been mainly conducted with treated filter papers for termites or extractives- containing agar media for decay fungi. Using these methods, the separation of crude extracts and bioassays are very time consuming. Thin layer chromatography (TLC) is a useful method for separating the mixture of organic compounds. It is also applicable to the crude extracts of wood consisting of many compounds. In TLC, silicagel, cellulose and other materials are used as stationary phases and we speculated that it would be to sepatare the crude extract on cellulose TLC plate (Cell - TLC) and directly apply it to bioassays, since termites and decay fungi can use the cellulose layer in Cell - TLC as their carbon sources. In this paper we report the applicability of Cell - TLC for biocidal screening of wood extractives against termites and decay fungi.
R Yusiasih, T Yoshimura, T Umezawa, Y Imamura


Gas chromatographic determination of 1,8-naphthalimide, N-Hydroxy-1,8-naphthalimide (N,N-naphthaloylhydroxylamine) and the sodium salt of N-Hydroxy-1,8-naphthalimide
2003 - IRG/WP 03-20259
A number of naphthalimide (NI) derivatives are used as efficient laser dyes, in medicine or in scanning electron microscopy. Only N,N-naphthaloylhydroxylamine (NHA) has been shown to be an effective wood preservative against wood decay fungi and termite damage. However, limited information is available concerning the analytical detection of NI-derivatives in treated timber. There is a clear need for the analytical characterisation; e.g. with regard to the penetration depth or the assessment of retention after leaching. This paper describes the development of a gas chromatographic method for determination of NI and their derivatives in timber. These investigations were carried out by means of direct thermal desorption-gas chromatography-mass spectrometry (TD-GS-MS) using the pure substances in solution, as well as direct analysis of treated southern yellow pine (SYP). It was shown that the identification of NHA in treated SYP is possible using this analytical technique. Furthermore first evidence is given for determining quantitative data. Surprisingly, the chromatograms and especially mass spectra obtained for NHA and the sodium salt of NHA are identical to the mass spectra of NI. The first results show that TD-GC-MS can be an option in determining the retention levels of NI and their derivatives in wood.
E Melcher, F Green III


Volatile organic compounds (VOC) measured during drying of impregnated timber
2004 - IRG/WP 04-50216
Discussion about drying of impregnated timber has taken place in the Nordic countries under eighties and nineties and goes on nowadays. The drying increase the value of production and the customer gets fewer problems when handles the timber. This introduces a positive attitude to the impregnation as a process and its products. Beside the important information about the advantages of impregnated timber drying, a great help for the integrity of branch and customers will be the acquirement of drying schedules considering the timber quality and emissions of harmful VOC. The objective of the present study was to measure the total content of possible emissions containing organic substances in the vented air during drying of Scots pine timber impregnated for above ground use (preservatives of class AB). A drying charge of 6 m3 consisting of 28120-mm boards was prepared for impregnation. The preservative, a copper-HDO (Wolmanit CX-8, 2 % conc.) was impregnated in the boards according to the full cell process carried out in an industrial autoclave. The impregnated charge was further dried in a laboratory batch kiln to final moisture content of 18.1 %. The duration of drying was 86 h. The content of VOC emitted in the air from the aminoethanol in preservative was measured by gas chromatography technique. Samples from the air were taken directly in and beside the drying kiln. The measurements were carried out in the beginning, middle and at the end of drying. The gas chromatography technique showed to be appropriate for quantitative measuring of the VOC emitted during drying of timber impregnated with Wolmanit CX-8. The emissions measured in the kiln chimney were most intensive in the beginning of drying when the free water was evacuated (31.4 ppm) and decreased exponentially to 7.8 ppm at the end of the process. The study generated some ideas about the organisation of drying schedule for impregnated timber in order to decrease the content of VOC. The results are interpreted regarding the requirements approved by the environmental authorities in Sweden.
N Terziev, V Djokic


The detection of organic solvent preservatives in wood by thin-layer chromatography
1975 - IRG/WP 357
A simple and rapid method for the detection of common organic solvent wood preservative materials is described. The method uses thin-layer chromatography after leaching of the preservative from sections of timber with chloroform. RF values and the sensitivity of the method are discussed and a routine procedure for identification of the organic and organometallic preservatives is proposed. Methods of achieving greater sensitivity for particular applications are also described.
B G Henshaw, J W W Morgan, N Williams


Selecting fumigants for treatment of internal decay in wood
1986 - IRG/WP 3370
A number of potential fumigants were screened with respect to their toxicity to decay fungi, (Poria carbonica, and Lentinus lepideus) and their sorption characteristics on Douglas Fir (Pseudotsuga menziesii Mirb. Franco) wood. Wafers of infected wood were exposed to different fumigant concentrations for various times then cultured to determine viability. The lethal concentration X time (ct) factors were determined for each fungus species and fumigant chemical. The "pulse chromatograph technique" was used to determine sorption isotherms for the fumigants to establish the relative degree of interaction between the chemicals and wood. Formaldehyde, chloropicrin (trichloronitromethane), and methylisothiocyanate (MIT) were the most fungitoxic of the chemicals investigated. MIT had the strongest affinity for wood, suggesting that this fumigant should persist longer in treated wood than chloropicrin. The proportion of vapor adsorbed on wood increased greatly with decreasing temperature and was generally higher in decayed wood than in sound wood and in 8% moisture content wood than in dry wood.
P A Cooper


Stability of bifenthrin in a commercial phenol-formaldehyde plywood glue
2003 - IRG/WP 03-30311
Liquid phenol formaldehyde (PF) glue mixes used for plywood manufacture are strongly alkaline. At this pH insecticidal additives may not be stable for long periods. In order to establish practical working life of the synthetic pyrethroid insecticide, bifenthrin, in liquid PF glues the concentration of bifenthrin in the glue mix was measured under laboratory conditions over a 24 hour period. Glue batches were prepared in a laboratory mixer set up on an electronic balance with two dose rates of bifenthrin. The glue was stirred continuously, with a cover in place to reduce evaporation. Four replicate portions of glue were removed from the mixer and applied to fluoropolymer-coated rubber discs at fixed periods. The discs were cured immediately in an oven, during which time the film set and became detached from the surface. These discs were extracted with toluene-formic acid (90:10) mixture and the extracts analysed using capillary column GC with electron capture detection. Bifenthrin was found to be exceptionally stable in alkaline PF glue. When the glue was mixed under conditions preventing premature polymerisation, no measurable bifenthrin degradation occurred during the 24 hours.
M J Kennedy, P A Collins, R D Vella


Interactions between wood and propiconazole in supercritical carbon dioxide
2009 - IRG/WP 09-40461
Understanding the movement and deposition of biocides in wood is a fundamental aspect of the supercritical wood impregnation process and a key issue in developing the process e.g. to handle wood of larger dimensions. Previous research on supercritical wood impregnation frequently reports of a biocide concentration gradient in impregnated samples i.e. a lower concentration of biocides in the core of the samples than nearer the surface. Researchers seldom comment on the reasons for the observed gradients, and the subject of biocide/wood interactions is generally overlooked. In this paper we investigate the interactions between wood and propiconazole in supercritical carbon dioxide and hypothesize that the reasons for the observed gradients is that wood has a chromatographic effect on the biocides as they move with the carbon dioxide through the wood matrix. The degree of interaction at different conditions is estimated by calculation of partition ratios.
A W Kjellow, O Henriksen


Profiling fungal community in wood decay ecosystem by Denaturing High-Performance Liquid Chromatography
2010 - IRG/WP 10-20443
A DNA-based fingerprinting technique, Denaturing High Performance Liquid Chromatography (DHPLC) was developed to profile fungal communities colonizing indoor timber. Molecular fungal diversity was assessed using amplification based on the Internal Transcribed Spacer (ITS1) rDNA of 74 wood samples collected from infected buildings in France. Due to its high sensitivity, the PCR-DHPLC technique was optimised for the detection and identification of wood rot fungi as well as ubiquitous contaminants. Serpula lacrymans was the most the widespread indoor wood-decay fungi and its occurrence accounts for 64% of total wood rot Basidiomycetes detected. The common cellar rot Coniophora spp. was detected in 9 environmental samples. White rot fungi like Donkioporia expansa and Heterobasidion annosum were also found in buildings. Whereas Basidiomycetes like Phlebiopsis gigantea, and Schizoporia radula were detected for the first time in the built environment. Ascomycetes responsible for wood decay were Guignardia vacinii and Oidiodendron griseum. The most prevalent moulds and Blue stain fungi found belong to the Aspergillus, Penicillium, and Cladosporium species. The identification of indoor fungi based on a molecular typing technique has provided useful data in community profiling of wood-decay ecosystem, without prior fungal isolation step and most of all put into evidence the coexistence of different wood rot fungi within the same microbiotope.
S Maurice, G Le Floch, M Le Bras-Quéré, J P Rioult, G Barbier


Surface energy characterization of thermally modified wood using inverse gas chromatography
2013 - IRG/WP 13-20532
The objective of this work is to characterize surface energetics of thermally modified wood. Such information may be useful for a better understanding and predictions of adhesion properties between the modified wood and other material systems, e.g. coatings, adhesives or matrices in composites. Inverse gas chromatography (IGC) was used to study the surface energy characteristics of thermally modified spruce in particle form. Two different wood component samples were prepared, one with a larger and one with a smaller particle size distribution. Measurements of BET specific surface area and dispersive surface energy distribution of the particle samples are presented. Results indicate that a ground wood component of a finer size distribution of thermally modified wood is less energetically heterogeneous compared with a component with a larger size distribution.
S Källbom, K Segerholm, D Jones, M Wålinder


A review on prediction methods of wood natural durability
2017 - IRG/WP 17-10892
Natural durability of timber may be defined as “inherent ability of timber to attack by wood destroying organisms (bacteria, fungi, insects, marine borers) without preservative treatment. On the base of biological tests, EN-350-2 standard (Afnor, 1994), describe the classification of wood species according to their natural durability. But these specifications are not adapted in the case of wood species with high variability of natural durability at inter or intra tree level In this case; the variability of natural durability could be detrimental to end-users. Because of standard testing methods are complex and time-consuming, it is important to propose alternative methods to predict natural durability. The focus of this review is to present different methods to predict natural durability based on the presence of chemical extractives, which have long been recognized as key features that impart natural durability of some wood species.
N Amusant, C Flora, J Beauchène, E Houël, C Duplais