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1

Measurement of radon potential from soil using a special method of sampling

Cosma C., Papp B., Moldovan M., Cosma V., Cindea C., Cindea C., Suciu L., Apostu A.

Acta Geophysica

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2010

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Vol. 58, no. 5

947-956

EN

Soil radon gas and/or its exhalation rate are used as indicators for some applications, such as uranium exploration, indoor radon concentration, seismic activity, location of subsurface faults, etc., and also in the studies where the main interest is the field verification of radon transport models. This work proposes a versatile method for the soil radon sampling using a special manner of pumping. The soil gas is passed through a columnof charcoal by using passive pumping. A plastic bottle filled with water is coupled to an activated charcoal column and the flow of water through an adjustable hole made at the bottom of bottle assures a controlled gas flow from the soil. The results obtained for the activity of activated charcoal are in the range of 20-40 kBq/m3, for a depth of approximately 0.8 m. The results obtained by this method were confirmed by simultaneous measurements using LUK 3C device for soil radon measurements. Possible applications for the estimation of radon soil potential are discussed.

2

Headspace solid phase microextraction using a porous-layer activated charcoal coating fused silica fiber for identification of volatile organic compounds emitted by Zataria multiflora boiss

Abkenar S. D., Yamini Y., Shemirani F., Assadi Y.

Chemia Analityczna

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2008

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Vol. 53, No. 2

277-287

EN

A laboratory-made porous-layer activated charcoal coated fused silica fiber was used as a microsolid phase in headspace solid phase microextraction coupled with gas chromato-graphy-mass spectrometry for identification of volatile organic compounds emitted by Zataria nmltiflora Boiss cultivated in Iran. The effect of different parameters, such as desorp-tion time, extraction temperature, sample mass, and extraction time on extraction efficiency was studied. The optimized conditions were: desorption time 2 min; extraction temperature 25°C; sample mass 0.200 g; extraction time 25 min. The main identified volatile components were: thymol (33.6%), carvacrol (17.0%), p-cymene (11.7%), linalool (5.0%), caryophyllene (2.9%), and a-terpineol (1.2%). These compounds were identified based on their retention indices and mass spectra (El, 70 eV). The proposed method for the analysis of volatile components emitted by Z. nmltiflora was very simple, fast, low-cost, and did not involve any organic solvents. The total analysis time including extraction and GC analysis was only 1 h, and no manipulation of the sample was required. Precision of the proposed method was good and RSD was less than 15%.

PL

Włókno krzemionkowe, samodzielnie pokryte węglem aktywnym, zastosowano do mikroeks-trakcji połączonej z chromatograf! ą gazową sprzężoną ze spektrometrią mas w celu identyfikacji lotnych związków organicznych, wydzielanych przez Zataria multiflora Boiss, uprawianą w Iranie. Badano wpływ na wydajność ekstrakcji różnych parametrów, takich jak: czas desorpcji, temperatura ekstrakcji, masa próbki i czas ekstrakcji. Optymalne warunki były następujące: czas desorpcji 2 min., temperatura ekstrakcji 25°C, masa próbki 0,200 g, czas ekstrakcji 25 min. Głównymi zidentyfikowanymi lotnymi związkami były: tymol (33,6%), karwakrol (17,0%), p-cymen(l 1,7%), linalol (5,0%), kariofilen (2,9%) i a-terpi-neol (l ,2%). Te związki zidentyfikowano na podstawie ich indeksów retencji i widm masowych (El, 70 eV). Zaproponowana metoda analizy lotnych związków wydzielanych przez Z. multiflora jest bardzo prosta, szybka, tania i nie wymaga stosowania żadnych rozpuszczalników organicznych. Całkowity czas analizy, uwzględniając ekstrakcję i analizę za pomocą chromatografii gazowej wynosił tylko l godzinę. Nie było potrzebne przygotowanie próbki. Precyzja proponowanej metody jest dobra i względne odchylenie standardowe wynosiło 15%.

3

Investigation of the influence of high humidity and exposure duration on the measurement results of radon concentration by means of PicoRad system in the CLOR calibration chamber

Stawarz O., Karpińska O., Mamont-Ciesla K.

Nukleonika

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2006

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Vol. 51,suppl.2

53-57

EN

PicoRad system based on activated charcoal collectors and liquid scintillation counter is one of the most popular passive methods of radon measurements which may be used both indoors and in other environments such as caves, tunnels, mines etc. It is well known that charcoal is also a very good adsorber of water vapor and it can reduce adsorption efficiency for radon. In PicoRad collectors, the charcoal is mixed with a dessicant to lower this effect. A series of expositions of PicoRad detectors was performed in a Central Laboratory for Radiological Protection (CLOR) radon calibration/climatic chamber to study the effect of high relative humidity on the airborne radon concentration measurements and the dependence of the results on the duration of exposure. The results obtained from the PicoRad system were referred to the mean concentrations delivered by an AlphaGUARD monitor, Genitron (GmbH), Germany. The main conclusions are the following: 1) the PicoRad system results are not affected by high relative humidity, including extreme values of 90-96%, for the duration of exposure up to ca. 24 h; 2) in the relative humidity range of 75-96% the correction coefficient linearly depends on the duration of exposure reaching a value of ca. 16 for 96 h exposure; 3) the PicoRad system delivers results corresponding better to the mean value of radon concentration in the last 6 h interval of exposure than that in the whole exposure duration. This finding is particularly important for the calibration of PicoRad collectors in the conditions of decreasing radon concentration due to radon decay.

4

3a,4,7,7a-tetrahydro -4,7-metanoinden - metoda oznaczania

Jeżewska A.

Podstawy i Metody Oceny Środowiska Pracy

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2003

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Nr 4 (38)

185--190

PL

Metoda polega na adsorpcji par 3a,4,7,7a-tetrahydro-4,7-metanoindenu na węglu aktywnym, desorpcji disiarcz- kiem węgla i analizie chromatograficznej (GC-FID) otrzymanego roztworu. Oznaczalność metody wynosi 1,25 mg/m3.

EN

The method is based on the adsorption of 3a,4,7,7a-tetrahydro-4,7-methanoindene vapours on active charcoal, desorption with carbon disulfide and gas chromatographic (GC-FID) analysis of the obtained solution. The determination limit of the method is 1.25 mg/m3.