RESUMO
The present study has investigated the influence of the filtration step of the liquid-liquid extraction (LLE) on the quantitative analysis of di-n-butyl phthalate (DnBP) in the wastewater treatment system of the University of Caxias do Sul (WWTS-UCS). During five months, five wastewater samples from the inflow and outflow points were collected and submitted to LLE with and without the filtration step. The organic extracts were analyzed by Gas Chromatography with Flame Ionization Detection (GC/FID). The DnBP removal in the filtered samples was 36%, and the median DnBP concentration at the outflow point was 17.45 µg/mL. For the unfiltered samples, the DnBP removal was 39%, and the median DnBP concentration at the outflow point was 21.45 µg/mL. According to these results, an important fraction of the contaminant is retained in the LLE filtration step leading to considerable errors in the quantification of the target compounds.
Assuntos
Dibutilftalato/análise , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/análise , Brasil , Cromatografia Gasosa , Filtração , Ionização de ChamaRESUMO
This work is focused on the chemical characterization of Maytenus ilicifolia extracts obtained from high-pressure CO2 extraction. The experiments were performed in a laboratory-scale unit, where the effect of particle size (35-200 mesh), CO2 mass flow rate (1-3 g/min), temperature (293-323 K), pressure (100-250 bar), and extraction time was investigated in terms of liquid yield and chemical composition of the extracts. Results show that the particle size and CO2 mass flow rate did not affect the liquid yield, whereas the extraction temperature and solvent density exerted a pronounced effect on both liquid yield and chemical distribution of volatile compounds. The extracts were chemically analyzed with regard to phytol, squalene, vitamin E, stigmasterol, friedelan-3-ol, friedelin, dodecanoic acid and geranyl acetate in a GC/MSD.