Papers by Keyword: Standard Curve

Abstract: Discussed with the method of the aqueous two-phase extraction of grape seed procyanidins optimum extraction conditions and extraction efficiency. Methods: Procyanidins extraction experimental conditions were optimized with the single, calculate the content and extraction rate of procyanidins from grape seeds with catechin standard curve comparison method. Results: Experiments show that: aqueous two-phase systems are made up of water 3.0 mL, ethanol 3.5 mL, ammonium sulfate 2.5 g, grape seed 0.5 g, centrifuged 10 min at 3600 r/min speed, placed 120 minutes, procyanidins at a rate of 0.23%, extraction rate reached 97.86%. Conclusions: This aqueous two-phase systems extraction rate, simple operation, environmental conservation, conditions required in practical applications easily met.

Abstract: Studying the distribution of the remaining oil is a crucial part in the process of developing oilfield. This study provides the further improvement of oil recovery rate with strong guarantee, and is a necessary method of developing further water controlling of individual reservoir oilfield. Saturation measurement techniques for remaining oil distribution research are particularly important. This paper describes the research of ways of measuring saturation in the resistance measurement experiment, the standard resistance - saturation curve and the factors influencing it. The results show that for different electrode installation, standard curve is mainly affected by the electrode distance. Standard curve is also greatly affected by water salinity, temperature and the difference in corespermeability.

Abstract: Determination of methylene blue concentrations of hydrogen sulfide in the air is sensitive and rapid ect. However, the standard curve tend to appear low line slope, leading to measurement errors. In the preparation of ZnS colloidal process, it is nitrogen as the carrier gas and protective gas. Its direct impact on the ventilation conditions colloidal particle size and uniformity of the precision for the calibration concentration have the significant impact, particles size appropriate uniform colloidal solution and the concentration can be more stable and accurate calibration by the standard curve. It was drawn to meet the requirement that is possible, too large or too small particles on the experimental results will lead to a greater impact. This article is related to the verification experiment of nitrogen ventilation conditions (uniform or not) with aeration velocity on the slope of the curve standard. The experiment we have come to: In this study, ZnS colloidal preparation on passing the nitrogen should be uniform, and the ventilation rate is smaller and needed to continuously bubbling one by one, in which the case of the experimental results, it is required by the standard curve that is drawn 0.1489, spiked recovery rate of 97.5% and 99.0%.

Abstract: In order to make quantitative analysis by internal standard method, 24 standard curves of inorganic compounds including quartz, corundum, TiO2, BaTiO3, etc. were obtained and the corresponding quantitative analyses were accomplished based on the quantitative analysis software attached in Rigaku D/Max-2200 X-Ray diffractometer. Results show that the coefficient of association R of the as-prepared curves are at the range of 0.928－0.980. By validating the samples with due content, it reveals that the analytical results are consistent with the actual values well, which indicate that the prepared standard curves are suitable for high-precision XRD phase quantitative analysis. Uniformity of samples is an important factor in the quantitative analysis by internal standard method.