Gas chromatography technique in the biodegradation study ofpolyethylene films with prooxidant additives

摘要

Biodegradation of polyethylene films with prooxidant additives were monitored by gasrnchromatography analysis of head-space gas in closed cultivation flasks. Concentrationrnof oxygen was determined on a column packed with molecular sieve 13X andrnconcentration of carbon dioxide on a column packed with Porapak R. The values werernthen used for calculation of sample’s actual mineralization. Sample flasks with stoppersrnwere specially designed for the experiment. The stoppers were equipped with threerninlets enabling to sample head-space gas through a gas tight septum and to flush therninner atmosphere with fresh air. High density polyethylene films and low densityrnpolyethylene films with content of prooxidant additives were subjected to weatheringrnunder natural conditions: exposed to sun light during 3 summer moths in southrnEuropean climate. Samples preoxidized in this way were subsequently used forrnbiodegradation tests. Samples were mixed with small amount of fresh soil or maturerncompost serving as a microbial inoculum and moisturized inert material and incubatedrnat 25°C for soil conditions and at 58°C for compost conditions simulation. Thernexperiment is still ongoing.