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Quantitative determination of glycerol in antarctic krill (Euphausia superba Dana) by high-performance thin-layer chromatography

100%

Han X. , Liu D.

Acta Chromatographica

2018

tom Vol. 30, no. 4

274--277

In this reported study, a direct high-performance thin-layer chromatographic (HPTLC) method was developed to qualitatively detect and quantitatively determine glycerol in Antarctic krill for the first time. This procedure was based on the extraction of glycerol by ultrasonic solvent extraction with anhydrous ethanol, silica-gel column chromatographic separation, HPTLC detection and quantification using methylene chloride–methanol (5:1, v/v) as the developing solvent and alkaline potassium permanganate as chromogenic agent. The content of glycerol was 1.3725 ± 0.218 mg/g in freeze-dried Antarctic krill. The structure of glycerol in the Antarctic krill was subsequently determined by gas chromatography–mass spectrometry (GC–MS) which verified the presence of the material in the krill. The HPTLC method exhibited excellent accuracy with a recovery of 90.1–103.3% and good precision with a relative standard deviation (RSD) of 1.59–4.84%. The results clearly exhibited the applicability of the proposed for quantifying glycerol in Antarctic krill.

Production of hydrogen from steam reforming of glycerol using nickel catalysts supported on Al2O3, CeO2and ZrO2

88%

Manfro R. L. , Ribeiro N. F. P. , Souza M. M. V. M.

Catalysis for Sustainable Energy

2012

tom 1

60-70

Nickel catalysts supported on Al2O3, CeO2 and ZrO2 were prepared by wet impregnation method and evaluated in steam reforming of glycerol. The catalysts were characterized by chemical composition, textural analysis, crystalline structure and reducibility. The structural characterization of the catalysts revealed a good dispersion of Ni particles using the Al2O3 support, needing higher reduction temperature. The reactions were performed at 500°C with 10 vol.% glycerol solution in a continuous flow reactor. All catalysts showed conversions close to 100%. The selectivity to gas products and formation of liquid by-products were found to be dependent on the type of support. The H2 selectivity showed the following trend: ZrO2 > Al2O3 ≈ CeO2. The catalyst supported on CeO2 showed low activity for water-gas shift reaction, with the highest CO selectivity. All catalysts presented a low formation of CH4. In the liquid phase some by-products were identified (hydroxyacetone, acetic acid, lactic acid, acetaldehyde, acrolein and ethanol) and secondary reaction routes were proposed. Coke formation was higher on Ni/Al2O3 catalyst, but no deactivation was observed during 8 h of reaction.

The effect of glycerol supplements on aerobic and anaerobic performance of athletes and sedentary subjects

88%

Patlar S. , Yalçin H. , Boyali E.

Journal of Human Kinetics

2012

tom 34

nr 1

69-79

The purpose of this study was to evaluate the effect of glycerol supplementation on aerobic and anaerobic exercise performance in sedentary subjects and athletes. The glycerol supplement treatments were as follows: 40 volunteers were selected and divided into two groups, sedentary and exercise groups. These two groups were further subdivided into two groups. The first group, the placebo (S), only consumed water; the second group (GS) consumed glycerol followed by water. Neither of these groups did any exercise for 20 days. The third and fourth groups consisted of the exercise group subjects; they were required to perform a 20-m shuttle run test every day for 20 days. The third group’s subjects, the placebo (E), only consumed water. The last group (GE) consumed glycerol followed by water. The Astrand Cycle Ergometer Test (ACET) was performed, and the Cosmed K4b2 portable gas analysis system was used to determine the aerobic capacity, while the Wingate Anaerobic Power Test (WAPT) was performed to determine the level of anaerobic power. The 20 Meter Shuttle Run Test (20MSRT) was performed after glycerol supplementation throughout the 20 days, and the exercise periods and distances were recorded. The glycerol supplement was found to have an increasing effect on aerobic and anaerobic performance in GS, E and GE. A similar effect was found for the covered distances and time in the same groups. However, an adverse effect was found on body weight.