Thin layer chromatography in combination with spectrophotometry and titrimetry has been used to evaluate chromatographic characteristics of bauxite constituents. The retention behaviors of four major constituents (Al...Thin layer chromatography in combination with spectrophotometry and titrimetry has been used to evaluate chromatographic characteristics of bauxite constituents. The retention behaviors of four major constituents (Al 3+ , Fe 2+ , Ti 4+ , Si 4+ ) in bauxite mineral have been examined on plain and modified layers of silica gel G, silica gel H and cellulose with mobile phases containing aqueous sodium chloride, formic acid and hydrochloric acid. Ternary separation of Al-Fe-Ti was achieved on chromatographic plates made of silica gel H. The pH effect and presence of impurity elements in samples, nature of stationary phases on the ternary separation and detection limits of bauxite constituents were studied. Silicon in bauxite was detected on cellulose plates. Quantitative determinations of Al 3+ , Fe 2+ and Ti 4+ on silica gel H impregnated with sodium formate layers were achieved by titrimetry and spectrophotometry.展开更多
采用顶空固相微萃取(headspace solid-phase microextraction,HS-SPME)和液液萃取(liquid-liquid extraction,LLE)结合全二维气相色谱飞行时间质谱(comprehensive two-dimensional gas chromatography time of flight mass spectrometry...采用顶空固相微萃取(headspace solid-phase microextraction,HS-SPME)和液液萃取(liquid-liquid extraction,LLE)结合全二维气相色谱飞行时间质谱(comprehensive two-dimensional gas chromatography time of flight mass spectrometry,GC×GC-TOF-MS)以及香气活度值(odour active value,OAV),对红星二锅头白酒的挥发性成分进行全面解析。研究发现,HS-SPME、LLE分别定性出928、802种挥发性化合物,共计定性出1304种挥发性化合物,共同定性出426种挥发性化合物。基于HS-SPME数据,通过香气数据库筛选出具有香气特征的382种香气化合物,其中酯类相对百分含量占比最高,其次是醇类、酸类和醛类。计算得到了49种香气化合物OAV>1,其中酯类(辛酸乙酯、异戊酸乙酯等)和萜烯类(β-大马酮)对白酒风味的贡献最大,醛类(异戊醛、己醛等)和含硫类(二甲基三硫)其次,醇类(1-辛烯-3-醇)和含氮类(2,3,5-三甲基吡嗪)也有一定风味贡献。该研究丰富了红星二锅头白酒的风味研究,也为下一步生产研究及调控提供了理论和数据支撑。展开更多
Quality standardization of complementary medicine is fundamental for industry and practice as it underpins the quality,safety and efficacy of Chinese herbal medicines.Current herbal standardizations are often based on...Quality standardization of complementary medicine is fundamental for industry and practice as it underpins the quality,safety and efficacy of Chinese herbal medicines.Current herbal standardizations are often based on the quantitative analysis of a single compound,which may not reflect the total characteristic,bioactive and toxic nature of the herbs or products.Therefore,there is a need to establish an internationally recognized methodology for quality standardization of Chinese herbal medicines.The analytical methods reviewed in this article are pharmacognosy,TLC,HPLC,LCMS,CE and chemo-metrics.This article also covers the developments and applications of these methods in quality standardization.Recent advances show that a combination of these methods creates an overall chemical profile of each herb.This is supported by results reviewed in this article and obtained in our laboratory tests on medicinal herbs including Hypericum perforatum,Morinda officinalis and Centella asiatica.Significant variations in active components have been observed between herbal samples and products.It is proposed that the identification of active components,pharmacological activities and eventual clinical applications are required for a comprehensive quality standardization system.Our findings indicate that the combination of various chromatographic and chemometric methods will advance the methodology of quality standardization and enhance the overall confidence in herbal medicine for the health practitioner and the public.展开更多
基金the project of"Development of rapid analytical procedures for bauxite and semi-quantitative analysis of scrapaluminium"supported by Science & Technology Wing, Ministry of Mines, Government of India.
文摘Thin layer chromatography in combination with spectrophotometry and titrimetry has been used to evaluate chromatographic characteristics of bauxite constituents. The retention behaviors of four major constituents (Al 3+ , Fe 2+ , Ti 4+ , Si 4+ ) in bauxite mineral have been examined on plain and modified layers of silica gel G, silica gel H and cellulose with mobile phases containing aqueous sodium chloride, formic acid and hydrochloric acid. Ternary separation of Al-Fe-Ti was achieved on chromatographic plates made of silica gel H. The pH effect and presence of impurity elements in samples, nature of stationary phases on the ternary separation and detection limits of bauxite constituents were studied. Silicon in bauxite was detected on cellulose plates. Quantitative determinations of Al 3+ , Fe 2+ and Ti 4+ on silica gel H impregnated with sodium formate layers were achieved by titrimetry and spectrophotometry.
文摘采用顶空固相微萃取(headspace solid-phase microextraction,HS-SPME)和液液萃取(liquid-liquid extraction,LLE)结合全二维气相色谱飞行时间质谱(comprehensive two-dimensional gas chromatography time of flight mass spectrometry,GC×GC-TOF-MS)以及香气活度值(odour active value,OAV),对红星二锅头白酒的挥发性成分进行全面解析。研究发现,HS-SPME、LLE分别定性出928、802种挥发性化合物,共计定性出1304种挥发性化合物,共同定性出426种挥发性化合物。基于HS-SPME数据,通过香气数据库筛选出具有香气特征的382种香气化合物,其中酯类相对百分含量占比最高,其次是醇类、酸类和醛类。计算得到了49种香气化合物OAV>1,其中酯类(辛酸乙酯、异戊酸乙酯等)和萜烯类(β-大马酮)对白酒风味的贡献最大,醛类(异戊醛、己醛等)和含硫类(二甲基三硫)其次,醇类(1-辛烯-3-醇)和含氮类(2,3,5-三甲基吡嗪)也有一定风味贡献。该研究丰富了红星二锅头白酒的风味研究,也为下一步生产研究及调控提供了理论和数据支撑。
基金supported by the International Science Linkages Australia China Special Found 2007,CH0701667established under the Australian Government's innovationstatement,Backing Australia's Ability and the University of Sydney International Program Development Fund (IDPF,2008)the China Australia Special Fund from the China National Science Fund Commission(Quality Standardisation,anti-inflammation and anti-depressant activities of Hypericum species and Morinda Officinalis,Yang Dp,2007)
文摘Quality standardization of complementary medicine is fundamental for industry and practice as it underpins the quality,safety and efficacy of Chinese herbal medicines.Current herbal standardizations are often based on the quantitative analysis of a single compound,which may not reflect the total characteristic,bioactive and toxic nature of the herbs or products.Therefore,there is a need to establish an internationally recognized methodology for quality standardization of Chinese herbal medicines.The analytical methods reviewed in this article are pharmacognosy,TLC,HPLC,LCMS,CE and chemo-metrics.This article also covers the developments and applications of these methods in quality standardization.Recent advances show that a combination of these methods creates an overall chemical profile of each herb.This is supported by results reviewed in this article and obtained in our laboratory tests on medicinal herbs including Hypericum perforatum,Morinda officinalis and Centella asiatica.Significant variations in active components have been observed between herbal samples and products.It is proposed that the identification of active components,pharmacological activities and eventual clinical applications are required for a comprehensive quality standardization system.Our findings indicate that the combination of various chromatographic and chemometric methods will advance the methodology of quality standardization and enhance the overall confidence in herbal medicine for the health practitioner and the public.
