Simultaneous detection of tocopherols, carotenoids, and chlorophylls in vegetable oils by direct injection C30RP-HPLC with coulometric electrochemical array detection

Increased environmental awareness and depletion of fossil petroleum resources are driving industry to develop alternative fuels that are environmentally more acceptable. Transesterified vegetable oil derivatives called ‘biodiesel’ appear to be the most convenient way of utilizing bio-origin vegetable oils as substitute fuels in diesel engines. The methyl esters of vegetable oils do not require significant modification of existing engine hardware. Previous research has shown that biodiesel has comparable performance and lower brake specific fuel consumption than diesel with significant reduction in emissions of CO, hydrocarbons (HC), and smoke but slightly increased NO x emissions. In the present experimental research work, methyl ester of rice-bran oil is derived through transesterification of rice-bran oil using methanol in the presence of sodium hydroxide (NaOH) catalyst. Experimental investigations have been carried out to examine the combustion characteristics in a direct injection transportation diesel engine running with diesel, biodiesel (rice-bran oil methyl ester), and its blends with diesel. Engine tests were performed at different engine loads ranging from no load to rated (100 per cent) load at two different engine speeds (1400 and 1800 r/min). A careful analysis of the cylinder pressure rise, heat release, and other combustion parameters such as the cylinder peak combustion pressure, rate of pressure rise, crank angle at which peak pressure occurs, rate of pressure rise, and mass burning rates was carried out. All test fuels exhibited similar combustion stages as diesel; however, biodiesel blends showed an earlier start of combustion and lower heat release during premixed combustion phase at all engine load-speed combinations. The maximum cylinder pressure reduces as the fraction of biodiesel increases in the blend and, at higher engine loads, the crank angle position of the peak cylinder pressure for biodiesel blends shifted away from the top dead centre in comparison with baseline diesel data. The maximum rate of pressure rise was found to be higher for diesel at higher engine loads; however, combustion duration was higher for biodiesel blends.

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Improving resolution for channel-format chip-based electrophoresis with electrochemical array detection

Journal of Separation Science ◽

10.1002/jssc.200301633 ◽

2003 ◽

Vol 27 (1-2) ◽

pp. 13-20 ◽

Cited By ~ 5

Author(s):

Steven W. Suljak ◽

Lynn A. Thompson ◽

Andrew G. Ewing

Keyword(s):

Array Detection ◽

Electrochemical Array

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Combustion characteristics of compression ignition engine fuelled with rapeseed oil–diesel fuel–n-butanol blends

Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles ◽

10.2516/ogst/2021001 ◽

2021 ◽

Vol 76 ◽

pp. 17

Author(s):

Jakub Čedík ◽

Martin Pexa ◽

Bohuslav Peterka ◽

Miroslav Müller ◽

Michal Holubek ◽

...

Keyword(s):

Vegetable Oils ◽

Diesel Fuel ◽

Rapeseed Oil ◽

Direct Injection ◽

Combustion Characteristics ◽

Solid Particles ◽

Compression Ignition ◽

Compression Ignition Engine ◽

Fuel Blend ◽

Fuel Blends

Liquid biofuels for compression ignition engines are often based on vegetable oils. In order to be used in compression ignition engine the vegetable oils have to be processed because of their high viscosity or it is also possible to use vegetable oils in fuel blends. In order to decrease the viscosity of the fuel blends containing crude vegetable oil the alcohol-based fuel admixtures can be used. The paper describes the effect of rapeseed oil–diesel fuel–n-butanol blends on combustion characteristics and solid particles production of turbocharged compression ignition engine. The 10% and 20% concentrations of n-butanol in the fuel blend were measured and analysed. The engine Zetor 1204, located in tractor Zetor Forterra 8641 with the power of 60kW and direct injection was used for the measurement. The engine was loaded through power take off shaft of the tractor using mobile dynamometer MAHA ZW500. The measurement was carried out in stabilized conditions at 20%, 60% and 100% engine load. The engine speed was kept at 1950 rpm. Tested fuel blends showed lower production of solid particles than diesel fuel and lower peak cylinder pressure and with increasing concentration of n-butanol in the fuel blend the ignition delay was prolonged and premixed phase of combustion was increased.

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Mangiferin and Hesperidin Transdermal Distribution and Permeability through the Skin from Solutions and Honeybush Extracts (Cyclopia sp.)—A Comparison Ex Vivo Study

Molecules ◽

10.3390/molecules26216547 ◽

2021 ◽

Vol 26 (21) ◽

pp. 6547

Author(s):

Anna Hering ◽

Jadwiga Renata Ochocka ◽

Helena Baranska ◽

Krzysztof Cal ◽

Justyna Stefanowicz-Hajduk

Keyword(s):

Stratum Corneum ◽

Ex Vivo ◽

Water Solution ◽

Ethanol Extract ◽

Ethanol Solution ◽

Dorsal Skin ◽

Photodiode Array ◽

Array Detection ◽

Electrochemical Array ◽

Ex Vivo Study

Polyphenolic compounds—mangiferin and hesperidin—are, among others, the most important secondary metabolites of African shrub Cyclopia sp. (honeybush). The aim of this study was to compare the percutaneous absorption of mangiferin and hesperidin from solutions (water, ethanol 50%, (v/v)) and extracts obtained from green and fermented honeybush (water, ethanol 50%, (v/v)). Research was performed with the Bronaugh cells, on human dorsal skin. The mangiferin and hesperidin distributions in skin layers (stratum corneum, epidermis, and dermis) and in acceptor fluid (in every 2, 4, 6, and 24 h) were evaluated by HPLC–Photodiode Array Coulometric and Coulometric Electrochemical Array Detection. The transdermal distribution of hesperidin was also demonstrated by fluorescence microscopy. Results indicated that mangiferin and hesperidin were able to cross the stratum corneum and penetrate into the epidermis and dermis. An advantage of hesperidin penetration into the skin from the water over ethanol solution was observed (451.02 ± 14.50 vs. 357.39 ± 4.51 ng/cm2), as well as in the mangiferin study (127.56 ± 9.49 vs. 97.23 ± 2.92 ng/cm2). Furthermore, mangiferin penetration was more evident from nonfermented honeybush ethanol extract (189.85 ± 4.11 ng/cm2) than from solutions. The permeation of mangiferin and hesperidin through the skin to the acceptor fluid was observed regardless of whether the solution or the honeybush extract was applied. The highest ability to permeate the skin was demonstrated for the water solution of hesperidin (250.92 ± 16.01 ng/cm2), while the hesperidin occurring in the extracts permeated in a very low capacity. Mangiferin from nonfermented honeybush ethanol extract had the highest ability to permeate to the acceptor fluid within 24 h (152.36 ± 8.57 ng/cm2).

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