Samples of urban air hydrocarbons were taken on specifically made adsorbent cartridges and analysed by gas chromatography after thermal desorption. The four isomeric butenes and 1,3-butadiene were favourably resolved and separated from the abundant alkanes on an aluminium oxide PLOT column. The concentrations of butadiene, reflecting outdoor urban exposure, were in the range of 0.5-5 micrograms...

The available epidemiologic data provide equivocal evidence that 1,3-butadiene is carcinogenic in humans; some available studies suggest that the lymphopoietic system is a target, but there are inconsistencies among studies in the types of tumors associated with 1,3-butadiene exposure, and there is no evidence of a relationship between length of exposure and cancer risk, as one might expect if ...

In order to determine the chemical composition distribution (CCD) of styrene-butadiene copolymers, gradient polymer elution chromatography has been performed. The separation is mainly based on differences in solubility among the copolymer molecules with different chemical composition. The solubility of a copolymer is dependent on the following parameters: temperature, type of solvent/non-solven...

BACKGROUND Traffic exhaust, refineries and industrial facilities are major sources of air toxics identified by the U.S. Environmental Protection Agency (U.S. EPA) for their potential risk to human health. In utero and early life exposures to air toxics such as benzene and 1,3-butadiene, which are known leukemogens in adults, may play an etiologic role in childhood leukemia that comprises the ma...

1,3-Butadiene is an important constituent of many products that we rely upon. It is currently prepared from non-sustainably derived sources. However, in the early part of the 20(th) Century the use of ethanol as a source of 1,3-butadiene has been reported. With the arrival of a cheap and bountiful supply of crude-oil derived sources the need for the sustainable route was deemed unnecessary. In ...

The OH radical initiated oxidation of 1,3-butadiene was studied under high NOx conditions by the LP-LIF method. We report a rate constant of (7.0 ± 0.3) ! 10"11 s"1 molecule"1 cm for OH addition to 1,3-butadiene which agrees well with values reported previously. Based on the analysis of OH cycling data combined with results of earlier isomeric selective studies, we have determined a branching r...

We report the direct production of 1,3-butadiene from the dehydration of 2,3-butandiol by using alumina as catalyst. Under optimized kinetic reaction conditions, the production of methyl ethyl ketone and isobutyraldehyde, formed via the pinacol-pinacolone rearrangement, was markedly reduced and almost 80 % selectivity to 1,3-butadiene and 1,3-butadiene could be achieved. The presence of water p...

In the title compound, C36H36N2, a product of the condensation reaction of 2,3-dimethyl-6-phenyl-vinyl-benzenamine and 2,3-butane-dione, the complete mol-ecule is generated by the application of an inversion centre. The central C-C bond in the 1,4-di-aza-butadiene fragment is trans-configured and situated about the inversion center. The dihedral angle between the ring attached to N and the 1,4-...

In the title complex, [Cr(C(4)H(6))(CO)(4)], the Cr(0) atom shows a distorted octa-hedral environment from four C atoms of the carbonyl ligands and the two π-bonds of the s-cis-1,3-butadiene ligand. The complex has an approximate non-crystallographic mirror symmetry m passing through the chromium atom, two carbonyl ligands and the mid-point of the central C-C bond of the s-cis-1,3-butadiene lig...