Eoo

MIa

b

c

d

e

a

ARAA

KMPDW

kp

1d

Journal of Cultural Heritage 13S (2012) S209–S215

Available online at

www.sciencedirect.com

valuation of decontamination methods of pesticide contaminated woodenbjects in museum collections: Efficiency of the treatments and influencen the wooden structure

arie Wörlea,∗, Vera Huberta,1, Erwin Hildbranda,2, Katja Hungera,3, Eberhard Lehmannb,4,ngo Mayerc,5, Gaby Petraka,6, Martin Pracherd,7, Urs von Arxc,8, Stefan Wülferte,9

Collection Centre, Swiss National Museum, Lindenmoosstr. 1, CH 8910 Affoltern a. Albis, SwitzerlandPSI Paul Scherrer Institute Villigen, CH 5232 Villigen PSI, SwitzerlandBern University of Applied Sciences, Architecture, Wood and Civil Engineering, Solothurnstrasse 102, CH-2500 Biel 6, SwitzerlandConsolidaS Kunst & Kulturgut GmbH, Alte Ziegelei, D 96110 Scheßlitz/Bamberg, GermanyBern University of Applied Sciences, Berne University of the Arts, Hallerstrasse 10, CH 3012 Bern, Switzerland

r t i c l e i n f o

rticle history:eceived 20 December 2011ccepted 10 January 2012vailable online 16 February 2012

eywords:useum objects

esticide contaminationecontamination methodsood microstructure

a b s t r a c t

In the second half of the 20th century, many valuable wooden museum objects were massively treatedwith toxic chloride pesticides (such as DDT, pentachlorophenol [PCP] or lindane) to protect them againstinsect and mold infestation. In the following years, synthetic pyrethroids replaced the classic pesticidesor the objects were even treated with mixtures of chemicals. Today, some of these toxic pesticides such asDDT have effloresced on the objects surfaces forming a white layer of crystals or they are emitted into theindoor air of storage rooms or exhibitions. In order to prevent the conservators as well as the visitors fromhealth risks, it is inevitable to decontaminate these objects. Two COST projects were started in order toevaluate suitable decontamination methods and to investigate their influence on the wooden microstruc-ture, the second project basing on the results of the first one. In the first project (SER COST project C07.0110“Evaluation on the effectiveness of decontamination methods for wooden art objects treated with woodpreservatives”), dummies of oak wood were soaked with a mixture of the pesticides pentachlorophenol,lindane und DDT and the distribution of the pesticides in the wood structure was determined by GC/MS,neutron radiography and �-XRF. Then two decontamination methods were adopted to the wooden dum-mies: a vacuum washing system (bhd-decon®, developed by the German company bhd Bautenschutz u.Hygienediensteleistungen GmbH, Dresden) and a vacuum temperature method (developed by the BerneUniversity of Applied Sciences (Architecture, Wood and Civil Engineering) in collaboration with the Berne

University of Applied Sciences (Berne University of the Arts). The efficiency of both methods was eval-uated by GC/MS and �-XRF, creating depth profiles of the distribution of the remaining pesticides. Thevacuum temperature method turned out to be too rough in means of temperature and pressure andwas limited to a relatively small sample chamber. Therefore, the vacuum washing method was applied

he efficiency was evaluated by �-XRF mappings. During the investigations by

to historical objects and t passive sample measurements on the surface of museum objects, it became apparent that the pesticideconcentration in the historical objects is much higher than assumed and, furthermore, that they contain amixture of classic pesticides with synthetic pyrethroids as a result of repeated treatment. For this reason

∗ Corresponding author. Tel.: +54 11 6772 7172; fax: +54 11 6772 7121.E-mail addresses: marie.woerle@snm.admin.ch (M. Wörle), vera.hubert@snm.admin.ch (V. Hubert), erwin.hildbrand@snm.admin.ch (E. Hildbrand),

atja.hunger@snm.admin.ch (K. Hunger), eberhard.lehmann@psi.ch (E. Lehmann), ingo.mayer@bfh.ch (I. Mayer), gaby.petrak@snm.admin.ch (G. Petrak),racher@consolidas.com (M. Pracher), Urs.vonArx@bfh.ch (U.v. Arx), stefan.wuelfert@hkb.bfh.ch (S. Wülfert).

1 Tel.: +41 44 762 13 92; fax: +41 44 762 13 61.2 Tel.: +41 44 762 13 91; fax: +41 44 762 13 61.3 Tel.: +41 44 762 13 93; fax: +41 44 762 13 61.4 Tel.: +41 56 310 29 63; fax: +41 56 310 21 99.5 Tel.: +41 32 344 03 43; fax: +41 32 344 02 90.6 Tel.: +41 44 762 13 70; fax: +41 44 762 13 61.7 Tel.: +49 9542 921055; fax: +49 9542 8029.8 Tel.: +41 32 344 02 02; fax: +41 32 344 02 90.9 Tel.: +41 31 848 38 80; fax: +41 31 848 38 51.

296-2074/$ – see front matter © 2012 Elsevier Masson SAS. All rights reserved.oi:10.1016/j.culher.2012.01.006

S210 M. Wörle et al. / Journal of Cultural Heritage 13S (2012) S209–S215

and for the investigation of a possible change of the wooden microstructure during decontamination, asecond project (SER No. C09.0031 “Studies on the distribution of wood preservatives and on structuralchanges of the wooden structure during decontamination treatment of museum objects polluted by chlo-rinated and pyrethroid preservatives”) was started. In this project, the wooden dummies were soaked ina mixture of pesticides of a higher concentration and the penetration depth was investigated dependingon the use of different solvents by GC/MS and �-XRF. The microstructure of the wood was investigatedby micro X-ray tomography and 3D microscopy before and after decontamination treatment.

1

twiooptdm

2

wslpLpotcItdtoGGoWtA

•

•

•

ctnt

. Research aim

The aim of these studies was to evaluate a suitable method forhe decontamination of valuable wooden museum objects, whichere preserved with toxic pesticides in order to avoid damage by

nsect or mold infestation. For the investigations, analytical meth-ds had to be found for a non-destructive detection of pesticidesn the objects by simulating the application of pesticides and theirossible removement on wooden dummies. Possible microstruc-ural changes caused by the decontamination process should beetermined and with this information suitable decontaminationethods should then be applied to real museum objects.

. Introduction

Nowadays it is well known that the generous application ofood preservatives mainly in the 1950s to the 1970s can cause

erious health risks not only in buildings but also in museum col-ections. Wood preservatives used at that time often containedentachlorophenol, DDT or lindane or even a mixture of them.ater on, pyrethroids were used additionally or replaced the “old”reservatives. On many wooden museum objects the efflorescencef DDT crystals on the surface can be observed and in the collec-ions an unpleasant smell is noticeable. Objects, which show DDTrystals or emit a strong odour cannot be displayed in the museum.n order to make these objects accessible for the public again ando avoid health problems both for the public and the museum staff,ifferent decontamination methods were developed for cleaninghe objects [1,2]. In the first project, two decontamination meth-ds were evaluated: a vacuum washing method developed by theerman company bhd Bautenschutz u. HygienedienstleistungenmbH in Dresden [3] and a vacuum temperature method devel-ped by the Berne University of Applied Sciences (Architecture,ood and Civil Engineering, BUAS-AWCE) in collaboration with

he Berne University of Applied Sciences (Berne University of therts, BUA).

The project was divided into three parts:

preparation of dummies made of oak wood with a pesticidecocktail and investigation of the solvent penetration by neutronradiography as well as the pesticide distribution in the woodstructure by gas chromatography mass spectrometry (GC/MS)and micro X-ray fluorescence spectrometry (�-XRF);application of the two decontamination methods on the dum-mies followed by neutron radiography for the examination of thepenetration depth of the solvent and GC/MS as well as �-XRF forinvestigating the efficiency;application of the vacuum washing method to museum objectsand �-XRF area scans for the investigation of the efficiency of thismethod on the objects’ surfaces.

In the second project, another pesticide solution with a higher

oncentration was prepared for new wooden dummies basing onhe results of on-site passive sampler measurements on contami-ated objects during the first project. Three different solvents andwo different application methods were used.

© 2012 Elsevier Masson SAS. All rights reserved.

In a first step, the pesticides distribution was investigated byGC/MS and �-XRF on wooden dummies. In a second step, the pen-etration behavior of the pesticides was investigated by GC/MS and�-XRF and, additionally, the distribution in the wood microstruc-ture was determined by �-XRF. In a third step, the efficiency ofthe two above mentioned decontamination methods was tested byGC/MS and �-XRF.

In the second project, an additional decontamination methodwas included which is also based on vacuum desorption. Thismethod was developed by Martin Pracher (ConsolidaS GmbH, Ger-many [4]) in collaboration with the Technical University of Munich.

As already mentioned, the second project is based on the resultsof the first one and both projects are interdependent. Therefore, theresults of both projects will be summarized in the following fourmain paragraphs: analytical investigation of the solvent and pesti-cide distribution in the wood, evaluation of two decontaminationmethods, investigation of the wooden microstructure before andafter the decontamination procedures, application and monitoringof one decontamination method on museum objects. The secondproject is not yet finished and therefore only the currently obtainedresults can be presented.

3. Results and discussion

3.1. Preparation of the wooden dummies–project 1 and 2

In order to avoid damage to valuable historic objects, all testswere previously carried out on wooden dummies. Many woodenobjects (e.g. furniture) are made of oak wood, which was there-fore chosen for the dummies. Moreover, the clearly structured andlarge-pored oak wood was especially suitable for the investigationof the wooden microstructure. In the first project, a mixture of pen-tachlorophenol, lindane and DDT in acetone (each 1000 ppm) wasused as a representative for former applied wood preservatives. Thedummies were completely immersed in this solution for 7 days. Inthe second project, the chosen surface for the treatment was thetangential direction since many elements of furniture are madeof tangential cut boards. For the investigation of the penetrationbehaviour of the pesticides, a solution containing pentachlorophe-nol, lindane, DDT and dieldrin each 10 g/L in three different solventswas prepared: acetone (for the comparison with the first project),ShellSol A 100 and ShellSol T (both used in old wood preseravtives).The soltution was applied (a) with a pipet (in order to simulatea volume controlled superficial application) and (b) immersion ofthe tangential plane in the pesticide solution (Fig. 1). Furthermore,solutions containing the above mentioned classic pesticides as wellas the pyrethroids permethrin and cypermethrin were preparedin order to represent the pesticide mixture which can presentlybe found in museum objects. For this mixture, the research is stillcontinuing and there are no results to present so far (Fig. 1).

3.2. Analytical investigation of the solvent and pesticide

distribution in the wood

Three different analytical methods were applied in orderto investigate the distribution of the solvent or the pesticide

M. Wörle et al. / Journal of Cultural Heritage 13S (2012) S209–S215 S211

ies by

mtmcM

3

vtmopasttdbvmmb

3

doarscoipoihpeTb

dofd

high resolution of the depth profiles. It is not possible to detectthe single pesticides themselves by �-XRF but since all of them arechlorinated compounds, the detection of chlorine was used as anindicator for the pesticide distribution [7]. In order to distribute

Fig. 1. (a, b) Preparation of the oak dumm

ixture, respectively: neutron radiography (Paul Scherrer Insti-ute Villigen) for the solvent distribution, gas chromatography

ass spectrometry (GC/MS, BUAS-AWCE) and micro X-ray fluores-ence spectrometry (�-XRF; Collection Centre of the Swiss Nationaluseum) for the pesticide distribution.

.2.1. Neutron radiographyBy neutron radiography the pesticides themselves cannot be

isualised with a good contrast to the wooden structure. Anyway,he solvents can be observed with a good contrast. Therefore, this

ethod was applied in order to determine the penetration depthf the solvent, which led to a maximum penetration depth of theesticides. In the first project, the penetration depth of the solventcetone was investigated. The results of the neutron radiographyhowed a high degree of dependency of the penetration depth onhe cut direction: in the tangential as well as in the radial directionhe solvent was penetrating only 2 mm whereas in the transversalirection the solution penetrated completely through the wholelock. In the latter direction the solvent went directly through theessels of the wood, which accelerated the penetration. By thisethod, no information could be obtained about a possible chro-atographic effect of the pesticide transportation into the wood,

ut a maximum penetration depth was characterised.

.2.2. Gas chromatography mass spectrometryFirst, the GC/MS analyses were carried out using a non-

estructive emission chamber design; but the low emission ratef the semi-volatile pesticides, namely DDT, led to an insufficientmount of absorbed material for a reliable quantification. For thiseason, a new method was developed using PDMS (polydimethyl-iloxane) samplers in the emission chambers which absorbed theompounds near to the contaminated test blocks, followed by des-rption and GC/MS analyses [5]. The results showed a constantlyncreasing concentration of the pesticides absorbed by the sam-lers even for DDT. This method can be used directly on the surfacef wooden objects [6]. On-site measurements on wooden objectsn the collection of the Swiss National Museum showed a muchigher concentration of pesticides as assumed and additionally theresence of permethrin and cypermethrin which lead to a newxperimental setup of the wooden dummies in the second project.he passive samplers provide a non-destructive analysis methodut they only allow obtaining semi-quantitative results.

In order to achieve a quantitative depth profile of the pesticide

istribution, GC/MS analyses of small cross sections were carriedut: first the oak dummies were cut into 50 �m cross sections. Smallractions of the thin cross section (10 mg) were extracted by 2 mLichloromethane and a quantitative depth profile with a resolution

(a) pipet application and (b) immersion.

of about 100 �m could be obtained by GC/MS (further details on themethod in [5]). Since this method provided information about thesingle pesticides, it could be determined that DDT, lindane and PCPpenetrated the oak dummies by only a few millimeters.

The results of the depth profiles by GC/MS showed a clear depen-dency on (a) the application method and (b) the different solvents.While the immersion of the dummies into the pesticide solutioncaused a deeper penetration, the concentration of the pesticides onthe surface was much higher by being applied with a pipet (pen-etration depth with acetone max. 1 mm by immersion and max.0.4 mm by superficial application). Acetone had the highest pen-etration potential; whereas the pesticide concentration by usingthe solvents ShellSol A 100 (aromatic hydrocarbons) and ShellSol T(iso alcanes) was much lower, independent of the kind of applica-tion. The concentration of the pesticides on the surface occurred todepend on their volatility: DDT > dieldrin > PCP > lindane. The pes-ticide concentration decreased quickly with the distance from thesurface (Fig. 2).

3.2.3. Micro X-ray fluorescence spectrometry�-XRF was used as a complementary analysis method to GC/MS

in both projects. The results of �-XRF and GC/MS were constantlycompared to each other with the aim to use �-XRF as a non-destructive investigation method on valuable museum objects. Forthe �-XRF investigations the mobile instrument ARTAX (Bruker)was used with a measurement point of 80 �m, which allows a

Fig. 2. Penetration depth of the pesticides. Solvent acetone, application by pipet.

S ural H

bwoter(fi1gasnr

tssi

p

3

3

dwroo

ttww

dmoarfiXr

tatca

sbdfcrloC

3

f

212 M. Wörle et al. / Journal of Cult

etween the different densities of the wooden structure, line scansere carried out in different directions: along one of the vessels,

n the dense wood fibres and across the vessels in different dis-ances to the rim. Lines of 20 mm length with measuring pointsach 0.1 mm were measured, resulting in 200 points per line. Theesults of the �-XRF investigation showed the deepest penetrationabout 10 mm) along the vessels (in transversal direction). In therst 10 mm the chlorine concentration decreased very fast and after0 mm, a stable low concentration could be detected. Both in tan-ential and radial direction (across the vessels) the concentrationt the rims was the highest, decreasing already after 2 to 4 mm to atable low value. These results correspond with the results from theeutron radiography of the solvent penetration. GC/MS and �-XRFesults are in good comparison.

Furthermore, it was possible to investigate the localisation ofhe pesticides in the wooden structure by �-XRF. Therefore, areacans with areas of 2 × 0.7 mm were chosen which contained bothmaller and bigger vessels as well as more dense xylem. An examples shown in Fig. 3 (solvent: acetone, application: immersion).

These pictures clearly indicate that the highest concentration ofesticides can be found in the dense xylem, not in the big vessels.

.3. Evaluation of two decontamination methods

.3.1. Vacuum washing method (bhd-decon®)The vacuum washing method developed by bhd [3] allows two

ifferent treatments: cleaning of the object by using only clearater or cleaning with a special decontamination solution. With

espect to the valuable museum objects (from which many are dec-ratively painted), only the first method was tested and applied inrder to avoid unpredictable interactions with delicate materials.

The method uses a combination of nozzles that spray water onhe surface and a vacuum cleaner system, which instantly removeshe now contaminated water from the surface. The contaminatedater contains dust, pesticide crystals etc. and is collected in aaste water container. Details can be requested at the company.

Due to the fact that the xylem is inhomogeneous, each oakummy is different. Therefore, in order to be able to compare theeasurement results, each test block was cut into two halves: one

f them was used for decontamination and the other one was kepts a reference for GC/MS. For �-XRF, the decontamination was car-ied out in two steps: a first washing procedure (pressure 2 bar)ollowed by drying the sample and XRF analyses and a second wash-ng procedure at the same pressure, again followed by drying andRF. This should show if a repetition of the procedure would beecommendable.

The efficiency of the method was investigated (a) by grindinghe decontaminated part of the oak block followed by extractionnd GC/MS. The results showed no significant reduction of the pes-icide concentration compared to the reference block. It must beonsidered that the vacuum washing method was most likely only

mainly mechanically cleaning of the wooden surface.The �-XRF investigation carried out again by a series of line

cans over the different directions showed a very similar distri-ution on the contaminated part of the oak blocks and on theecontaminated dummies. Therefore, there was no significant dif-erence between one or two washing procedures. However, inontrast to the museum objects, the oak dummies showed no efflo-escence of pesticide crystals, so a surface cleaning would mostikely give no measurable difference. Anyway, in cases of museumbjects, which allow surface cleaning only this is a viable method.orresponding investigations will be presented in chapter 3.5.

.3.2. Vacuum temperature methodThis method was developed in a collaborative research project

rom the Berne University of Applied Sciences, Architecture, Wood

eritage 13S (2012) S209–S215

and Civil Engineering, BUAS-AWCE and the Berne University ofApplied Sciences, University of the Arts, BUA. The method combinesa vacuum chamber with a mantle heating, allowing automatic pres-sure and temperature control and cryofocusing of the evaporatedpesticides in a liquid nitrogen cooled cold trap.

The test blocks were again cut into two halves for keepingone half as a reference. The halves for the decontamination weretreated for 8 hours with a pressure of 15 mbar and a temperatureof 80 ◦C. The evaluation of this method by GC/MS showed a reduc-tion of single pesticides up to 35% over the whole volume. A higherdecontamination rate could not be achieved, probably due to aninsufficient mass transport.

As a result, it could be shown that the vacuum washing methodis restricted to the surface but is nevertheless useful for the removalof superficial contamination. At the present state of development,the vacuum temperature method cannot be applied to biggerobjects due to the restricted size of the vacuum chamber, and,moreover, a temperature of 80 ◦C might be harmful to valuableobjects and is not applicable to most organic museum objects.

An additional decontamination method, the vacuum desorption(ConsolidaS GmbH, Germany [4]), is working with low pressure andmoderate heating in several cycles with a constant deduction of thepolluted gases through a filter system. This method was alreadysuccessfully brought to the market and will be applied during thesecond project, too.

3.4. Investigation of the wooden microstructure before and afterdecontamination treatment

These investigations were carried out with wooden dummies,which were not treated with pesticides because only the effect ofthe decontamination methods on the wooden structure should beshown.

3.4.1. Vacuum temperature method: micro X-ray tomographyWooden dummies were heated for 8 hours at 80 ◦C with a

chamber pressure of 15 mbar. Small pieces of 15 × 2 × 2 mm wereprepared for tomography. By rotating the samples by 180◦ data setswere obtained which were treated by mathematical processes. Thisallowed visualizing virtual cross sections. The results showed nosignificant changes of the wooden structure at that stage. Though,tests at higher temperatures lead to cell damages and analyses ofdifferently heated wood blocks by REM even showed a damagedxylem at lower temperatures [8].

3.4.2. Vacuum washing method: 3D microscopyFor the 3D microscopy, oak dummies were investigated with-

out applying the vacuum washing method and after one and twoapplications (clean water, 2 mbar). All three cut directions wereinvestigated by choosing an area of 3 × 3 mm and 100 × magnifi-cation. For a 3D presentation, one picture was taken every 10 to20 �m in height. Furthermore, for a 3D surface profile one pictureevery 5 �m was taken with a magnification of 400.

The 3D microscopy pictures showed a significant cleaning effectof the vacuum washing method. It was visible that small loose par-ticles were removed. The cells of the parenchyma, which were notdamaged by sawing and therefore were intact before the wash-ing procedure occurred to be unmodified after washing, only somecut fibres were bent. The intact tyloses of the big vessel cells werealso not damaged by the washing procedure. Tyloses, which were

damaged by sawing, occurred to be slightly bent after the washingprocedure. Both profile measurements and single pictures by 3Dmicroscopy showed that the vacuum washing method caused onlyvery slight changes of the microstructure on the surface of the wood

M. Wörle et al. / Journal of Cultural Heritage 13S (2012) S209–S215 S213

F rea scr

aw

3o

cS1dnabau

ig. 3. (a) Photograph of scanned area, (b) X-ray fluorescence spectrometry (XRF) aegions: less chloride.

nd definitely no changes of the microstructure deeper inside theood structure (Fig. 4).

.5. Application and monitoring of the vacuum washing methodn museum objects

The vacuum washing method was then evaluated on a bureauabinet made of walnut veneered spruce from the collection of thewiss National Museum. This piece of furniture dated to 1700 to750 contains four drawers beneath the desk and several smallrawers inside the upper cupboard (Fig. 5a). All over the unvar-ished parts of the cabinet, especially on the inside of the cabinet

nd the wooden substrate of the drawers, pesticide crystals coulde found (Fig. 5b). One of the small drawers was chosen for thepplication of the vacuum washing method and the efficiency eval-ated by �-XRF (Fig. 5).

Fig. 4. 3D picture (a) before and (b) after vacuum washing. On

an. Grey scale in counts per seconds (chloride), lighter regions: more chloride, dark

For the evaluation, an area of 35 × 40 mm was chosen for anarea scan setting one measurement point per mm resulting in ca.1500 points. The area was scanned before the decontaminationand after one, two and three washing procedures. The area scanbefore decontamination showed a significant amount of chlorinespread all over the surface. After one and two washing proce-dures, a distinct change could be noticed. By optical evaluationit could be noticed that already after one washing procedure thedust and the crystals were mostly removed. The area scans afterone, two and three washing procedures showed a significant reduc-tion of chlorine. After one washing procedure, 70% of the chlorinewas removed, after two times ca. 80 to 85% and after three times

nearly 90%, again proving the vacuum washing method as a suitablemethod for surface cleaning (Fig. 6).

Nevertheless, it could be possible that the removal of the sur-face pollution acts like opening a seal and leads to mobilization

ly very slight changes visible, pointed out by the arrows.

S214 M. Wörle et al. / Journal of Cultural Heritage 13S (2012) S209–S215

Fig. 5. (a) Bureau cabinet dated from 1700 to 1750, (b) DDT crystals in drawer.

F ing ans 80 to

ocom

4

a

ig. 6. X-ray fluorescence spectrometry (XRF) area scans (a) before vacuum washeconds (chloride). The results correspond to a chlorine reduction on the surface of

f pesticides from deeper regions of the wood and therefore to re-rystallisation of pesticides on the surface. For this reason, museumbjects treated by the vacuum washing method must be regularlyonitored for possible new superficial pesticides.

. Conclusion

With respect to valuable wooden museum objects, whichre contaminated with pesticides, two methods for their

d (b) after two vacuum washing applications. The colour scale shows counts per 85%.

decontamination were evaluated. Suitable non-destructive anal-ysis methods had to be found for the evaluation. Most of thetests in this project were carried out on oak dummies. Only inthe last part of the project tests on a real museum object wereexecuted.

The penetration depth of solvents was visualised by neutronradiography. In a destructive way, the penetration profile of thepesticides before and after decontamination could be illustratedby GC/MS. In a similar manner, �-XRF proved to be an adequate

ural H

mr�tova

ts

at

rbwstbo

hdom

•

•

[

[

[

[

[

[

[containing wood preservatives in art objects, Studies in Conservation 48 (3)(2003) 195–202.

M. Wörle et al. / Journal of Cult

ethod for the same question. Furthermore, by detecting the chlo-ine distribution on the oak dummies as well as on museum objects,-XRF gave the evidence to be a suitable non-destructive method

o detect a pesticide contamination on valuable wooden museumbjects. The penetration behavior and its dependency on the sol-ent of the pesticides could be shown by GC/MS and �-XRF as wells their distribution in the wooden microstructure by �-XRF.

Moreover, the influence of the decontamination treatment ofhe two evaluated methods on the wooden structure could behown by micro X-ray tomography and 3D microscopy.

By applying these analytical methods to the wooden dummiesnd, after this, to a real museum object, the efficiency of two decon-amination methods could be shown.

The vacuum washing method (bhd-decon®) turned out to be aeliable method to remove superficial pesticide and other particleound pollution, however. Anyway, the contamination inside theood structure was not affected. The vacuum temperature method

howed a relatively good efficiency but could only be applied tohe wooden dummies due to the limited size of the pressure cham-er. Moreover, applying 80 ◦C to sensible or even painted museumbjects is questionable respectively not applicable.

Now, in the second project, wooden dummies with muchigher pesticide concentration are decontaminated by the vacuumesorption method of ConsolidaS [4]. The efficiency and suitabilityf this method will be evaluated in the same way as for both otherethods. The final results of this project will be published later on.

Analytical instrumentation:

neutron radiography: measurements carried out at the NeutronTransmission Radiography (NEUTRA) Station of the Swiss Spalla-tion Neutron Source SINQ (Paul Scherrer Institute), visualisation

by ImageJ software;micro X-ray tomography: working group TOMCAT (TOmographicMicroscopy and Coherent rAdiology experimenTs) at the SwissLight Source (SLS), Paul Scherrer Institute;

[

eritage 13S (2012) S209–S215 S215

• 3D microscopy: Keyence VHX-1000 16-bit high resolution micro-scope, real zoom lens 100 to 1000 (Vh-Z100r);

• �-XRF: micro X-ray fluorescence spectrometer ARTAX 800(Bruker, Germany): rhodium tube, Peltier cooled silicon driftdetector, polycapillary lens, filter system (Al filter for the detec-tion of Cl). Semiquantitative analysis by ARTAXControl software;

• GC/MS: GC/MS Agilent 6890 N/5975, autosampler MPS2 (Gerstel,Germany).

Acknowledgements

We are grateful to the European Union and the Swiss State Secre-tariat for Education and Research (SER) for supporting and fundingthe research projects.

References

1] A. Unger, Umweltschädliche Holzschutzmittel, Möglichkeiten der Dekon-taminierung und Maskierung, Restauro 3/1998, S. 186–91, 1998.

2] A. Unger, M. Eisbein, E. Jelen, T. Berger, F. Gockel, Kunstschätze schonend ent-giften, gas aktuell 66, 1/2004, S. 20–5, 2004.

3] bhd Bautenschutz und Hygienedienstleistung GmbH, Neulußheimer Str. 61, D01465 Dresden/OT Langebrück.(http://www.bhd-dresden.de/).

4] ConsolidaS Kunst & Kulturgut GmbH, Dipl. Rest. Univ. Dr. phil. Martin Pracher,Alte Ziegelei, D 96110 Scheßlitz/Bamberg.(http://www.consolidas.de).

5] I. Mayer, K. Hunger, U.V. Arx, M. Wörle, V. Hubert, G. Petrak, E. Lehmann, Destruc-tive and non-destructive methods for the evaluation of chlorinated pesticidesconcentration and emissions from wooden art objects. Conference proceedings,International Conference on wooden cultural heritage: evaluation of deteriora-tion and management of change, Hamburg, Germany, 2009.

6] I. Mayer, K. Hunger, U.V. Arx, M. Wörle, V. Hubert, G. Petrak, E. Lehmann, A newapproach to cost-effective on-site measurements of pesticide emissions fromindividual wooden objects. Conference contribution: 4th International Confer-ence of COST Action IE0601, Izmir, Turkey, 2010.

7] J. Bartoll, A. Unger, K. Püschner, H. Stege, Micro-XRF investigations of chlorine-

8] S. Häcki, M. Weiersmüller, Untersuchung von Trocknungsschäden imHolzgewebe von Kulturgütern, term paper, Bern University of Applied Sciences,Architecture, Wood and Civil Engineering, 2010.