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141.
Peter Boev 《History of Photography》2013,37(2):155-172
Abstract In a brief span of only 135 years, photography has been turned from a purely technical invention into a symbol of our time, and this itself constitutes one of the most remarkable phenomena of modern civilization. The illustration has become the full-fledged partner of literature, and photography a basic means of acquiring and recording knowledge. Photography has become a tool of science, and a means of the aesthetic exploration of reality. It spread rapidly all over the world; but its appearance in Bulgaria was greatly delayed because the Bulgarian people were still under Ottoman domination and some 39 years since its invention had passed before liberation finally came. 相似文献
142.
采用高效液相色谱和气相色谱相结合,对异丙隆及其间位异构体、邻位异构体进行分离和测定。试验结果表明:异丙隆线性相关系数为0.996 1,相对标准偏差为0.19%,平均回收率为100.11%;间位异构体线性相关系数为0.995 9,相对标准偏差为2.26%,平均回收率为97.05%;邻位异构体线性相关系数为0.992 5,相对标准偏差为5.02%,平均回收率为97.61%。 相似文献
143.
Kil Sun Yoo Eun Jin Lee Daniel Leskovar Bhimanagouda S. Patil 《Journal of food science》2012,77(12):C1279-C1284
Abstract: We developed a system to run the Folin‐Ciocalteu (F‐C) total phenolic assay, in artichoke extract samples, which is fully automatic, consistent, and fast. The system uses 2 high performance liquid chromatography (HPLC) pumps, an autosampler, a column heater, a UV/Vis detector, and a data collection system. To test the system, a pump delivered 10‐fold diluted F‐C reagent solution at a rate of 0.7 mL/min, and 0.4 g/mL sodium carbonate at a rate of 2.1 mL/min. The autosampler injected 10 μL per 1.2 min, which was mixed with the F‐C reagent and heated to 65 °C while it passed through the column heater. The heated reactant was mixed with sodium carbonate and color intensity was measured by the detector at 600 nm. The data collection system recorded the color intensity, and peak area of each sample was calculated as the concentration of the total phenolic content, expressed in μg/mL as either chlorogenic acid or gallic acid. This new method had superb repeatability (0.7% CV) and a high correlation with both the manual method (r2= 0.93) and the HPLC method (r2= 0.78). Ascorbic acid and quercetin showed variable antioxidant activity, but sugars did not. This method can be efficiently applied to research that needs to test many numbers of antioxidant capacity samples with speed and accuracy. 相似文献
144.
A simple and accurate high-performance liquid chromatography (HPLC) coupled with diode array detector (DAD) and evaporative light scattering detector (ELSD) was established for the determination of six... 相似文献
145.
Tijiang Shan Weibo Sun Hao Liu Shan Gao Shiqiong Lu Mingan Wang Wenxian Sun Zhiyi Chen Shu Wang Ligang Zhou 《International journal of molecular sciences》2012,13(9):11275-11287
Ustiloxins are cyclopeptide mycotoxins produced by the pathogenic fungus Villosiclava virens of rice false smut. Ustiloxins A and B as two main mycotoxins were determined conveniently by LC-ESI-MS in the water extract from rice false smut balls which were mostly composed of the chlamydospores and mycelia of the pathogen. Both ustiloxins A and B in the water extract were also quantitatively analyzed by HPLC. This is the first report on the determination and analysis of ustiloxins A and B simultaneously by LC-ESI-MS and HPLC in false smut balls of rice. 相似文献
146.
Purpose: To establish a HPLC testing method of the content of bulk picoplatin and its impurities. Method: the separation was perform on a C18 column(4.6 mm×250 mm, 5 m) with potassium dihydrogen phosphate-aceton-itrile as the mobile phase at a flow rate of 1.0 mL/min. The detecting wavelength was set at 210 nm, and the column temperature was set at 30℃. Result: in the method validation, the linear relationship modulus of picoplatin is 0.9999, the systemic precision is 0.44%, the method precision is 0.74%, the average recovery rate is 99.62%, the LOD and LOQ of picoplatin is 0.2 ng and 1.0 ng. The average resolution of picoplatin and its impurities is more than 2. Conclusion: The established method is good specificity, high sensitivity, and good repeatability which could provide scientific evidence for the quality control of picoplatin and its impurities. 相似文献
147.
148.
A method using normal phase high performance liquid chromatography for the analysis of olefins and diolefins in cracked petroleum samples is proposed and validated in this work. A silver-impregnated silica column is used to separate olefin and diolefin species, resulting in accurate quantification of both group-types. Separations are completed using an isocratic hexane mobile phase, with no sample clean up or backflushing required. Results from the analysis of 11 model compounds are shown, as well as quantification data for four representative samples; figures of merit are also described. 相似文献
149.
150.