<p> <em>An accurate, precise, simple and economical High Performance Liquid Chromatographic method for the estimation of </em><em>S-acid lactic in the process of fermentation</em><em> of </em><em>Aloe Vera</em><em> gel</em><em> has been developed. The method is using </em><em>HIQSIL 100 C18column (Length: 250nm, Diameter: 4.6nm, Particle size: 5μ) with potassium dihydrogen phosphate as mobile phase. The separation was performed by UV detector at 210 nm</em> <em>wavelength. The flow rate was kept at 1mL/min and the injection volume was 20μl. The results obtained showed that the linearity of the method was 0-180 ppm, and the correlation coefficient was found to be 0.999. Detection limit of the method for S-acid lactic was 1.15 ppm. The mean recoveries were from 95% to 99%. The reproducibility RSDs ranged from 2.87%. The results demonstrated the suitability of the HPLC approach for the analysis of S-acid lactic in the process of fermentation from Aloe Vera gel.</em></p>

<p> <em>An accurate, precise, simple and economical High Performance Liquid Chromatographic method for the estimation of </em><em>S-acid lactic in the process of fermentation</em><em> of </em><em>Aloe Vera</em><em> gel</em><em> has been developed. The method is using </em><em>HIQSIL 100 C18column (Length: 250nm, Diameter: 4.6nm, Particle size: 5μ) with potassium dihydrogen phosphate as mobile phase. The separation was performed by UV detector at 210 nm</em> <em>wavelength. The flow rate was kept at 1mL/min and the injection volume was 20μl. The results obtained showed that the linearity of the method was 0-180 ppm, and the correlation coefficient was found to be 0.999. Detection limit of the method for S-acid lactic was 1.15 ppm. The mean recoveries were from 95% to 99%. The reproducibility RSDs ranged from 2.87%. The results demonstrated the suitability of the HPLC approach for the analysis of S-acid lactic in the process of fermentation from Aloe Vera gel.</em></p>

Abstract-HCTN7. Natural essential oils of plant have been applied over the world becausef these biosafety natural compounds. Applicant levels from the steaming pot among the common people to the raw essential oils or pure extract essence from original natural sources for making special products. Eucalyptus essential oil obtains from Eucalyptus leaves contain 998 mg/L α-eucalyptol, Cymbopogon essential oil obtains from lemon grasses contain 64,8% citral. These essential oils have been paid attention because of there were abundant raw materials in the Mekong Delta area. Therefore, the study was conducted to aim of extracting essential oils from Eucalyptus and Cymbopogon leaves as well as examminate their effect on mosquito repellent. The factors affecting the amount of extracted oils are the time to withered materials (0 h; 2.5 h; 5 h), how the way to preliminary treatment of the materials (crushing or without crushing), the distilled water aidding (400 mL, 500 mL, 600 mL)/300g materials, the distillation time (2 h; 2.5 h; 3 h). The data was evaluated by statistical program. Mixing ratio of Cymbopogon oil: Eucalyptus oil: coconut oil, one of the important criteria to be investigated for evaluating the ability to repel mosquitoes is in turn (40:10:50), (35:15:50), (30:20:50). Experimental results reveal that crushing (Cymbopogon), without crushing (Eucalyptus) of fresh materials, 500 mL of distilled water aidding, 3 h of distillation time were the best during the oil extraction process. The contents of mixing formula of the Cymbopogon essiential oil: Eucalyptus essiential oil: coconut oil (40: 10: 50) is the most effective with the ability to falling mosquitoes only after 5 minutes and killing 84.67% mosquitoes after 24 hours. The natural mixture of Cymbopogon oil, Eucalyptus oil, and coconut oil, safety for human health and more friendly to the environment.Keywords: Coconut oil, Eucalyptus essential oil, Eucalyptus leaves, Cymbopogon essential oil, Cymbopogon leaves, mosquito repellent, steam distillation.Classification numbers:1.4.6.

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