Naslov
The carbon isotopic composition of dried and carbonized plant samples

Autori
Vreča, Polona ; Šturm, Martina ; Krajcar Bronić, Ines

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
ESIR 2011, Central European Geology 54, 2011, / - Budimpešta, 2011, 26-26

Skup
ESIR 2011 - Isotope Workshop XI

Mjesto i datum
Budimpešta, Mađarska, 04.07.2011. - 08.07.2011

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
carbon isotope composition; plants; nucler power plant; carbonization

Sažetak
Monitoring 14C activity in plant samples in the vicinity of the Nuclear power plant Krško (NPPK) is performed regularly since 2006 to estimate the possible influence on environmental 14C levels and the possible contribution to the effective dose of local population through food chain. When reporting 14C activity (Bq kg-1 C) of the samples, it is necessary to consider the stable isotopic composition of carbon (δ13C) and the fractionation that occurs during photosynthesis. In addition, isotopic fractionation can occur also during sample preparation. Therefore, the aim of our study was to analyse selected C3 and C4 plant samples in order to (1) determine their actual δ13C values to be used for correction of 14C activity and (2) investigate eventual isotopic fractionation which might occur during sample carbonization process, i.e. pyrolysis by analysing dried and carbonized counterparts of selected plant samples. In this study δ13C of 37 dried and 34 carbonized samples of apples, maize (leaves and grain) and wheat collected in four sampling campaigns (2008 and 2009) in the vicinity of NPPK was determined. Carbonized samples were ground to powder and homogenized. The dried samples were ground using different grinding methods. Apple samples were ground to powder and homogenized in an agate mortar. Maize and wheat samples were lyophilized after being frozen in liquid nitrogen. Four lyophilized samples were ground in a mill. During this process it was not possible to obtain completely homogenized samples, therefore, the rest of maize and wheat samples were ground and homogenized in an agate mortar. δ13C was determined using a Europa 20–20 isotope ratio mass spectrometer (IRMS). The mean δ13C value for analysed C3 plant samples (i.e. apple and wheat) and for C4 plant samples (i.e. maize) was close to -27‰ and -12‰, respectively. In wheat, apple and maize samples, no significant differences (at p < 0.05) were observed between the dried and carbonized samples, however, an up to 2.2‰ and 1.8‰ difference was observed for particular apple and maize leaves sample, respectively. The influence of variability of d13C values on reported 14C activity will be discussed.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Geologija

POVEZANOST RADA