A gradient HPLC method was established for the determination of harpagoside and cinnamic acid in Radix Scrophulariae (Xuanshen) and a proposition was put forward for the lowest content of the characteristic and active...A gradient HPLC method was established for the determination of harpagoside and cinnamic acid in Radix Scrophulariae (Xuanshen) and a proposition was put forward for the lowest content of the characteristic and active constituent (harpagoside) for qualified Radix Scrophulariae. The experimental conditions were as follows: Ultrasphere ODS column (250 mm 4.6 mm, 5 mm), mobile phase: acetonitrile-water (containing 1.0% acetic acid) (20:8050:50) (20 min), flow-rate 1 mLmin-1, room temperature, detection wavelength 278 nm. Twenty-eight samples of Xuan-shen (Radix Scrophulariae) from different districts of China were analyzed and the contents of harpagoside and cinnamic acid in Xuan-shen were 0.041~0.244% and 0.012~0.068% respectively. The recoveries (RSD)% were 97.13(0.80)% for harpagoside and 99.38(0.51)% for cinnamic acid. The method is simple and accurate. It can be used for the quality control of Radix Scrophulariae. We propose that the content of harpagoside in qualified Radix Scrophularia should be no less than 0.05%.展开更多
Steelmaking–refining–Continuous Casting(SCC) scheduling is a worldwide problem, which is NP-hard. Effective SCC scheduling algorithms can help to enhance productivity, and thus make significant monetary savings. Thi...Steelmaking–refining–Continuous Casting(SCC) scheduling is a worldwide problem, which is NP-hard. Effective SCC scheduling algorithms can help to enhance productivity, and thus make significant monetary savings. This paper develops an Improved Artificial Bee Colony(IABC) algorithm for the SCC scheduling. In the proposed IABC, charge permutation is employed to represent the solutions. In the population initialization, several solutions with certain quality are produced by a heuristic while others are generated randomly. Two variable neighborhood search neighborhood operators are devised to generate new high-quality solutions for the employed bee and onlooker bee phases, respectively. Meanwhile, in order to enhance the exploitation ability, a control parameter is introduced to conduct the search of onlooker bee phase. Moreover, to enhance the exploration ability,the new generated solutions are accepted with a control acceptance criterion. In the scout bee phase, the solution corresponding to a scout bee is updated by performing three swap operators and three insert operators with equal probability. Computational comparisons against several recent algorithms and a state-of-the-art SCC scheduling algorithm have demonstrated the strength and superiority of the IABC.展开更多
The determination of the geographical origin as well as the adulteration of natural products is a technical problem due to similar chemical composition between an adulterant and the original. It is assumed that tartar...The determination of the geographical origin as well as the adulteration of natural products is a technical problem due to similar chemical composition between an adulterant and the original. It is assumed that tartaric acid comes from natural sources, however there is no specific regulation for this claim. This paper describes the use of isotope mass spectrometry associated with chemometrics to classify different samples of tartaric acid. The results showed that the variables δ^13C, δ^18O and δ^2H allowed the discrimination of tartaric acid samples by geographical origin and production method. By using a combination of chemometfic analysis it was possible to confirm a notoriousseparation of the samples. Thus, this is a promising method to be applied in the quality control and authenticity of tartaric acid.展开更多
A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of ...A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of UAE were obtained by using Box-Behnken design of response surface methodology. Chromatography was carried out using a Kromasil C18 column by gradient elution with 0.1% phosphoric acid aqueous solution for HPLC-UV. All calibration curves showed good linear correlation coefficients （R^2〉0.999 6） and recoveries （from 97.3% to 104.9%） were acceptable. 1,1-diphenyl-2-picrylhydrazyl （DPPH） method was employed to test the antioxidant activity of the extract from the samples. The proposed method was successfully applied to quantifying eight components in nine samples of M.cordata, and significant variations of alkaloid contents and antioxidant aetivity of the samples from different habitats were demonstrated. It presents a powerful proof for the selection of the best sources to extract eight kinds of alkaloids.展开更多
文摘A gradient HPLC method was established for the determination of harpagoside and cinnamic acid in Radix Scrophulariae (Xuanshen) and a proposition was put forward for the lowest content of the characteristic and active constituent (harpagoside) for qualified Radix Scrophulariae. The experimental conditions were as follows: Ultrasphere ODS column (250 mm 4.6 mm, 5 mm), mobile phase: acetonitrile-water (containing 1.0% acetic acid) (20:8050:50) (20 min), flow-rate 1 mLmin-1, room temperature, detection wavelength 278 nm. Twenty-eight samples of Xuan-shen (Radix Scrophulariae) from different districts of China were analyzed and the contents of harpagoside and cinnamic acid in Xuan-shen were 0.041~0.244% and 0.012~0.068% respectively. The recoveries (RSD)% were 97.13(0.80)% for harpagoside and 99.38(0.51)% for cinnamic acid. The method is simple and accurate. It can be used for the quality control of Radix Scrophulariae. We propose that the content of harpagoside in qualified Radix Scrophularia should be no less than 0.05%.
基金Supported by the National Natural Science Foundation of China(51705177,51575212)the Program for New Century Excellent Talents in University(NCET-13-0106)the Program for HUST Academic Frontier Youth Team
文摘Steelmaking–refining–Continuous Casting(SCC) scheduling is a worldwide problem, which is NP-hard. Effective SCC scheduling algorithms can help to enhance productivity, and thus make significant monetary savings. This paper develops an Improved Artificial Bee Colony(IABC) algorithm for the SCC scheduling. In the proposed IABC, charge permutation is employed to represent the solutions. In the population initialization, several solutions with certain quality are produced by a heuristic while others are generated randomly. Two variable neighborhood search neighborhood operators are devised to generate new high-quality solutions for the employed bee and onlooker bee phases, respectively. Meanwhile, in order to enhance the exploitation ability, a control parameter is introduced to conduct the search of onlooker bee phase. Moreover, to enhance the exploration ability,the new generated solutions are accepted with a control acceptance criterion. In the scout bee phase, the solution corresponding to a scout bee is updated by performing three swap operators and three insert operators with equal probability. Computational comparisons against several recent algorithms and a state-of-the-art SCC scheduling algorithm have demonstrated the strength and superiority of the IABC.
文摘The determination of the geographical origin as well as the adulteration of natural products is a technical problem due to similar chemical composition between an adulterant and the original. It is assumed that tartaric acid comes from natural sources, however there is no specific regulation for this claim. This paper describes the use of isotope mass spectrometry associated with chemometrics to classify different samples of tartaric acid. The results showed that the variables δ^13C, δ^18O and δ^2H allowed the discrimination of tartaric acid samples by geographical origin and production method. By using a combination of chemometfic analysis it was possible to confirm a notoriousseparation of the samples. Thus, this is a promising method to be applied in the quality control and authenticity of tartaric acid.
基金Project(20576142) supposed by the National Natural Science Foundation of China Project(2009DFA31270) supported by the International Cooperation Project of Ministry of Science and Technology of China
文摘A reliable ultrasound-assisted extraction （UAE） method combined with HPLC-UV for quantification of eight active alkaloids in fruits of Macleaya cordata （Willd） R. Br. was developed. The optimization conditions of UAE were obtained by using Box-Behnken design of response surface methodology. Chromatography was carried out using a Kromasil C18 column by gradient elution with 0.1% phosphoric acid aqueous solution for HPLC-UV. All calibration curves showed good linear correlation coefficients （R^2〉0.999 6） and recoveries （from 97.3% to 104.9%） were acceptable. 1,1-diphenyl-2-picrylhydrazyl （DPPH） method was employed to test the antioxidant activity of the extract from the samples. The proposed method was successfully applied to quantifying eight components in nine samples of M.cordata, and significant variations of alkaloid contents and antioxidant aetivity of the samples from different habitats were demonstrated. It presents a powerful proof for the selection of the best sources to extract eight kinds of alkaloids.
