Search results for " Oil"
showing 10 items of 1049 documents
Determination of pyrethroid insecticide residues in vegetable oils by using combined solid-phases extraction and tandem mass spectrometry detection
2005
Abstract A methodology has been developed for the determination of pyrethroid insecticide residues in vegetable oils, based in a solid-phase extraction (SPE) with combined solid supports phases. Several solid phases such as florisil, alumina, C18 and graphitized carbon black were tested in order to minimize fat residues, being a combination of treated alumina and C18 which provided the best results. Oil samples were partitioned with acetonitrile–hexane (1:1) and then eluted through a combined column packed with deactivated basic-alumina and C18, employing the acetonitrile extract as elution solvent. Gas chromatography tandem mass spectrometry was used for determination. Tetramethrin, Bifent…
Enhanced styrene removal in a two-phase partitioning bioreactor operated as a biotrickling filter: Towards full-scale applications
2017
Abstract Styrene vapor abatement was investigated in a two-phase partitioning bioreactor operated as a biotrickling filter (TPPB-BTF). The removal performance of the TPPB-BTF was simultaneously compared with a conventional BTF, which served as a control. Industrial-grade silicone oil was used as the non-aqueous phase in the TPPB-BTF due to its high affinity for styrene. Both bioreactors were operated at styrene inlet concentrations ranging from 55 to 323 mg C m −3 and empty bed residence times (EBRT) of 15–30 s, corresponding to pollutant loading rates of 13–77 g C m −3 h −1 . Both bioreactors exhibited styrene removal efficiencies (REs) higher than 90% at an EBRT of 30 s. Nevertheless, th…
Essential oil counterfeit identification through middle infrared spectroscopy
2018
Abstract Infrared spectroscopy (FTIR) has been employed for a fast quality control of commercial essential oils from different plant species. 47 samples were obtained from Algerian and Spanish market and directly measured, without any previous treatment, by attenuated total reflectance Fourier transform Infrared spectroscopy (ATR-FTIR), in the wavenumber region between 4000 and 550 cm−1. Pure essential oils were obtained by hydro- and steam-distillation extraction methods and their ATR spectra obtained. Results found evidenced the presence of solvents in some commercial formulations and permitted a rapid authentication of pure essential oils correctly extracted from those diluted. The propo…
Classification of Extra Virgin Olive Oils Produced at La Comunitat Valenciana According to Their Genetic Variety Using Sterol Profiles Established by…
2009
A method to classify extra virgin olive oils (EVOOs) according to their genetic variety using sterol profiles obtained by high-performance liquid chromatography (HPLC) with mass spectrometry (MS) detection has been developed. Sterol extracts were chromatographed on a dC18 Atlantis column (100x3 mm, 3 microm) with a gradient of acetonitrile/water (0.01% acetic acid) at a flow rate of 1.0 mL min(-1) and positive-ion mode MS detection. Using linear discriminant analysis of the HPLC-MS data (extracted ion chromatograms), EVOO samples belonging to six genetic varieties cultivated at La Comunitat Valenciana, Spain (Arbequina, Borriolenca, Canetera, Farga, Picual, and Serrana), were correctly clas…
Bio-phenols determination in olive oils: Recent mass spectrometry approaches
2021
Extra virgin olive oil (EVOO) is largely used in Mediterranean diet, and it is also worldwide apprised not only for its organoleptic properties but also for its healthy effects mainly attributed to the presence of several naturally occurring phenolic and polyphenolic compounds (bio-phenols). These compounds are characterized by the presence of multiple phenolic groups in more or less complex structures. Their content is fundamental in defining the healthy qualities of EVOO and consequently the analytical methods for their characterization and quantification are of current interest. Traditionally their determination has been conducted using a colorimetric assay based on the reaction of Folin…
Classification of vegetable oils according to their botanical origin using n-alkane profiles established by GC-MS.
2013
n-Alkane profiles established by gas chromatography-mass spectrometry (GC-MS) were used to classify vegetable oils according to their botanical origin. The n-alkanes present in corn, grapeseed, hazelnut, olive, peanut and sunflower oils were isolated by means of alkaline hydrolysis followed by silica gel column chromatography of the unsaponifiable fractions. The n-alkane fraction was constituted mainly of n-alkanes in the range C8-C35, although only those most abundant (15 n-alkanes, from 21 to 35 carbon No.) were used as original variables to construct linear discriminant analysis (LDA) models. Ratios of the peak areas selected by pairs were used as predictors. All the oils were correctly …
Supercritical CO2 extraction of essential oils from orange peel
1996
The supercritical fluid extraction of orange essential oil was studied using dehydrated orange peel (0.0538 kg H2O kg−1 dm) from naveline cultivars as raw material and CO2 as solvent. The effect of operation conditions was analyzed in a series of experiments at 313 and 323 K and pressures between 1 and 25 MPa. Furthermore, the effect of CO2 flow rate and particle size of orange peel was studied in the range of 0.5 to 3.5 kg h−1 and 0.1 to 10 mm. The subcritical CO2 dissolves hardly any essential oils, however, on reaching the critical point, the amount of essential oils dissolved increased with pressure, within the range of pressures considered in this study. Increasing solvent mass flow de…
Chemical Constituents ofGynura cusimbuaAerial Parts
2007
Abstract The essential oil isolated from the aerial parts of Gynura cusimbua was analyzed by GC and GC/MS. Forty-seven constituents totaling 91.92% of the oil were identified. The major constituents of the oil are myrcene (31.0%), β- phellandrene (12.43%), eugenol (6.34%), α-humulene (6.20%), dodecyl acrylate (6.09%), α-copaene (5.61%), phytol (3.21%), germacrene D (3.0%), cryptone (2.04%), 2,4-ditertbutylphenol (1.62%), α-pinene (1.33%), α-cadinene (1.26%), caryophyllene oxide (1.24%) and β-caryophyllene (1.08%).
Essential oil analysis ofTeucrium libanitisandT. turredanumby GC and GC-MS
2003
The chemical composition of the six essential oils obtained from Teucrium libanitis and Teucrium turredanum collected at different localities was analysed by GC and GC–MS. Fifty-three constituents were identified. The oil of T. libanitis is characterized by the monoterpene α-pinene (9.9–21.2%) and the sesquiterpene δ-cadinene (5.3–9.7%), while that of T. turredanum had a higher content of sesquiterpenoids: β-caryophyllene (15.6–32.6%), α-humulene (4.7–10.1%) and β-bisabolol (6.4–8.3%), and a lower percentage of monoterpenoids (<1%). A multivariate procedure (hierarchical clustering) for detecting natural grouping established that T. libanitis and T. turredanum constitute two independent taxa…
Determination of lecithin and soybean oil in dietary supplements using partial least squares-Fourier transform infrared spectroscopy.
2008
Lecithin and soybean oil in dietary supplements were determined by Fourier transform infrared spectrometry transmission measurements in dichloromethane in combination with a partial least squares (PLS) regression. Two different PLS models were developed, using 16 synthetic mixtures of analytes in dichloromethane, making measurements in the spectral range from 931.8 to 1252.3 cm(-1) for lecithin and from 911.4 to 1246.9 cm(-1) and 1695.3 to 1774.5 cm(-1) for soybean oil. Seven products from the Spanish market with lecithin concentrations between 21.1% and 99.1% and soybean oil concentrations between 0% and 37.2% were analyzed by the proposed method and the data was compared to a chromatograp…