Microwave assisted-semi bionic extraction (MASBE) process for lignans from Fructus Forsythiae was studied. The influences of solvent pH value, microwave power, dosage of solvent and irradiation time were investigated....Microwave assisted-semi bionic extraction (MASBE) process for lignans from Fructus Forsythiae was studied. The influences of solvent pH value, microwave power, dosage of solvent and irradiation time were investigated. Optimum extracting parameters were determined by orthogonal experiments as follows: pH value of solvent at first extraction is 5.5-6.0, that at the second extraction is 7-8; microwave power is 700 W; mass ratio of Fructus Forsythiae to water is 1-12; irradiation time is 10 min, and extracting times is two. Under these optimal conditions, the yield of lignans reaches 0.364%. Compared with the conventional extraction methods, the MASBE process has the advantages of high extraction rate, high extraction selectivity.展开更多
Lignin serves as one of the most important molecular fossils for tracing Terrestrial Organic Matters （TOMs） in marine environment. Extraction and derivatization of lignin oxidation products （LOPs） are crucial for ...Lignin serves as one of the most important molecular fossils for tracing Terrestrial Organic Matters （TOMs） in marine environment. Extraction and derivatization of lignin oxidation products （LOPs） are crucial for accurate quantification of lignin in marine sediment. Here we report a modification of the conventional alkaline cupric oxide （CuO） oxidation method, the modification consisting in a solid phase extraction （SPE） and a novel on-column derivatization being employed for better efficiency and reproducibility. In spiking blanks, recoveries with SPE for the LOPs are between 77.84% and 99.57% with relative standard deviations （RSDs） ranging from 0.57% to 8.04% （n=3）, while those with traditional liquid-liquid extraction （LLE） are from 44.52% to 86.16% With RSDs being from 0.53% to 13.14% （n=3）. Moreover, the reproducibility is greatly improved with SPE, with less solvent consumption and shorter processing time. The average efficiency of on-column derivatization for LOPs is 100.8%±0.68%, which is significantly higher than those of in-vial or in-syringe derivatization, thus resulting in still less consumption of derivatizing reagents.Lignin in the surface sediments sampled from the south of Yangtze River estuary, China, was determined with the established method. Recoveries of 72.66% to 85.99% with standard deviation less than 0.01mg/10g dry weight are obtained except for p-hydroxybenzaldehyde. The lignin content ∑8 （produced from 10g dry sediment） in the research area is between 0.231 and 0.587mg. S/V and C/V ratios （1.028 ± 0.433 and 0.192±0.066, respectively） indicate that the TOMs in this region are originated from a mixture of woody and nonwoody angiosperm plants; the high values or （Ad/Al）v suggest that the TOMs has been highly degraded.展开更多
基金Project(06SK3042) supported by the Science and Technology Commission Foundation of Hunan Province, China
文摘Microwave assisted-semi bionic extraction (MASBE) process for lignans from Fructus Forsythiae was studied. The influences of solvent pH value, microwave power, dosage of solvent and irradiation time were investigated. Optimum extracting parameters were determined by orthogonal experiments as follows: pH value of solvent at first extraction is 5.5-6.0, that at the second extraction is 7-8; microwave power is 700 W; mass ratio of Fructus Forsythiae to water is 1-12; irradiation time is 10 min, and extracting times is two. Under these optimal conditions, the yield of lignans reaches 0.364%. Compared with the conventional extraction methods, the MASBE process has the advantages of high extraction rate, high extraction selectivity.
基金supported by the National Basic Research Program of China (973 Program, Grant No. 2010CB428901)the National Natural Science Foundation of China (NSFC, Grant No. 41020164005,41276067)the team of 973 Program Grant No. 2010CB428701 for the help during sampling
文摘Lignin serves as one of the most important molecular fossils for tracing Terrestrial Organic Matters （TOMs） in marine environment. Extraction and derivatization of lignin oxidation products （LOPs） are crucial for accurate quantification of lignin in marine sediment. Here we report a modification of the conventional alkaline cupric oxide （CuO） oxidation method, the modification consisting in a solid phase extraction （SPE） and a novel on-column derivatization being employed for better efficiency and reproducibility. In spiking blanks, recoveries with SPE for the LOPs are between 77.84% and 99.57% with relative standard deviations （RSDs） ranging from 0.57% to 8.04% （n=3）, while those with traditional liquid-liquid extraction （LLE） are from 44.52% to 86.16% With RSDs being from 0.53% to 13.14% （n=3）. Moreover, the reproducibility is greatly improved with SPE, with less solvent consumption and shorter processing time. The average efficiency of on-column derivatization for LOPs is 100.8%±0.68%, which is significantly higher than those of in-vial or in-syringe derivatization, thus resulting in still less consumption of derivatizing reagents.Lignin in the surface sediments sampled from the south of Yangtze River estuary, China, was determined with the established method. Recoveries of 72.66% to 85.99% with standard deviation less than 0.01mg/10g dry weight are obtained except for p-hydroxybenzaldehyde. The lignin content ∑8 （produced from 10g dry sediment） in the research area is between 0.231 and 0.587mg. S/V and C/V ratios （1.028 ± 0.433 and 0.192±0.066, respectively） indicate that the TOMs in this region are originated from a mixture of woody and nonwoody angiosperm plants; the high values or （Ad/Al）v suggest that the TOMs has been highly degraded.
