RESUMEN
Waste valorisation through pyrolysis generates solid, liquid and gaseous fractions that need to be deeply characterised in order to try to recover secondary raw materials or chemicals. Depending on the waste and the process conditions, the liquid fraction obtained (so-called pyrolysis oil) can be very complex. This work proposes a method to quantitatively measure the composition of pyrolysis oils coming from three types of polymeric waste: (1) plastic packaging from sorting plants of municipal solid waste, (2) plastic rich fractions rejected from sorting plants of waste of electrical and electronic equipment and (3) end-of-life carbon/glass fibre reinforced thermoset polymers. The proposed methodology uses a gas chromatography (GC) coupled with mass spectrometer detector (MS) analytical technique, a certified saturated alkanes' mix, an internal standard and fourteen model compounds. Validation of the methodology concluded that the average relative error was between -59 wt% and +62 wt% (with standard deviations between 0 wt% and 13 wt%). Considering that the state-of-the-art scenario to quantify complex plastic pyrolysis oils as a whole is almost none and that they are usually evaluated only qualitatively based on the area percentage of the GC-MS chromatograms, the presented quantification methodology implies a clear step forward towards complex pyrolysis oil compositional quantification in a cost-effective way. Besides, this quantification methodology enables determining what proportion is being detected by GC-MS with respect to the total oil. Finally, the presented work includes all the Kováts RI for complex temperature-program gas chromatography of all the signals identified in the analysed pyrolysis oils, to be readily available to other researchers towards the identification of chemical compounds in their studies.
RESUMEN
To evaluate the protective effect of diabetes mellitus (DM) on renal function of rats treated with gentamicin (GM), male Wistar-EPM rats (250-350 g) were treated with streptozotocin (SZ; 45 mg/kg) and starting 10 days after induction of diabetes, GM was given for ten consecutive days at a daily dose of 40 mg/kg. In the GM-treated group (G), a significant fall in inulin and sodium-p-aminohippurate clearance was obtained (3.57 + or - 0.16 and 12.59 + or - 0.61 ml min-1kg-1 vs 6.43 + or - 0.21 and 17.98 + or - 0.47 ml min-1 kg-1 in control rats (C), respectively) while in the animals previously injected with SZ (diabetic + gentamicin, DG group) these changes injected with SZ (diabetic + gentamicin, DG group) these changes were not observed. The diabetic (D), g and DG group showed a significant rise in urinary flow compared to C (0.165 + or - 0.009, 0.145 + or - 0.007 and 0.173 + or - 0.009 ml min-1kg-1 vs 0.109 + or - 0.003 ml min-1kg-1, respectively); however, only in G was the U/P inulin ration significantly decreased when compared to C. The fractional excretion (FE) of sodium and postassium was significantly augmented in G when compared to C, D and DG. Thus, diabetes protected against gentamicin nephrotoxicity at both the glomerular and tubular level, although it did not promote a reduction in urinary flow