超临界流体萃取法对有机锡化合物的选择性萃取

研究了用超临界流体萃取法直接从脂肪基质的固体样品（大豆粉）中选择性地萃取有机锡化合物的方法。模拟试样萃取结果表明：用较低压力和较高温度的超临界态ＣＯ２作流动相时，有机锡达到最大萃取率，而脂肪类物质仅被少量萃取，从而消除了脂肪类物质对超临界流体色谱法测定有机锡的干扰。     

黄酮类化合物的超临界流体色谱分离

利用超临界流体色谱成功地分离了黄酮类化合物，研究了流动相组成，柱条件，压力及温度的影响。发现流动相组成是影响色谱分离的最主要因素；其次，色谱柱条件也是影响分离的一个很重要的因素，硅胶基质的键合苯基柱比较适合于极性黄酮类化合物的分离。     

超临界流体色谱法分离手性化合物的进展

超临界流体色谱（ＳＦＣ）是一种很有潜力的色谱分离技术,可以弥补高效液相色谱（ＨＰＬＣ）和气相色谱（ＧＣ）在手性对蚋物分离方面的不足。本文不但介绍了ＳＦＣ仪器的结构特点,ＳＦＣ与手性固定相（ＣＳＰｓ）结合在手性分离领域中的应用和最新进展,还对ＳＦＣ与其它色谱技术的分离效果进行了评价。文献３９篇。     

超临界二氧化碳流体萃取法测定玩具中15种致敏芳香化合物

该文以欧盟新玩具指令中限用或禁用的15种致敏芳香化合物为研究目标,研究了超临界二氧化碳萃取压力、温度、夹带剂等条件对萃取效率的影响,建立了超临界流体萃取/气相色谱-质谱联用仪测定玩具中15种致敏芳香化合物的分析方法。最佳萃取条件为：萃取温度50 ℃,压力300 bar,二氧化碳流速30 g/min,夹带剂甲醇含量3%,动态萃取30 min,静态萃取30 min。萃取物经DB-17MS色谱柱分离后,采用质谱仪进行检测,内标法定量。15种化合物在0.02~60 μg/mL范围呈良好线性,相关系数为0.993 2~0.999 9,检出限(S/N=10) 为0.02~0.09 μg/mL。该法检测聚丙烯(PP)、聚乙烯(PE)、丙烯腈-丁二烯-苯乙烯(ABS)塑料的回收率分别为79.6%~114.5%、75.0%~118.9%、72.7%~114.9%,相对标准偏差为3.2%~11.0%、0.6%~11.6%、3.5%~11.0%。建立的方法灵敏、环保,可用于玩具中致敏芳香化合物的检测。     

超临界二氧化碳流体萃取法测定玩具中15种致敏芳香化合物

该文以欧盟新玩具指令中限用或禁用的15种致敏芳香化合物为研究目标,研究了超临界二氧化碳萃取压力、温度、夹带剂等条件对萃取效率的影响,建立了超临界流体萃取/气相色谱-质谱联用仪测定玩具中15种致敏芳香化合物的分析方法。最佳萃取条件为:萃取温度50℃,压力300 bar,二氧化碳流速30g/min,夹带剂甲醇含量3%,动态萃取30 min,静态萃取30 min。萃取物经DB-17MS色谱柱分离后,采用质谱仪进行检测,内标法定量。15种化合物在0.02~60μg/mL范围呈良好线性,相关系数为0.993 2~0.999 9,检出限(S/N=10)为0.02~0.09μg/mL。该法检测聚丙烯(PP)、聚乙烯(PE)、丙烯腈-丁二烯-苯乙烯(ABS)塑料的回收率分别为79.6%~114.5%、75.0%~118.9%、72.7%~114.9%,相对标准偏差为3.2%~11.0%、0.6%~11.6%、3.5%~11.0%。建立的方法灵敏、环保,可用于玩具中致敏芳香化合物的检测。     

超临界流体色谱法测定银杏叶提取物中的黄酮类化合物

采用超临界流体色谱法分离测定了银杏叶提取物水解后的三个甙元－－槲皮素、山奈酚、异鼠李素的含量。以苯基柱为固定相,二氧化碳－乙醇－磷酸９０：９．９８：０．０２Ｖ／Ｖ）为流动相,三个黄酮甙元获得良好的分离,利用各甙元的转换因子计算了黄酮化合物的总黄酮的含量,这种方法定量结果准确,重现性好。     

超临界流体萃取-高效液相色谱离线联用分析灵芝中三萜类化合物

在系统考察压力、温度和时间对萃取率影响的基础上,利用超临界流体萃取技术提取了灵芝子实体中的三萜类化合物。其最佳萃取条件为:压力15 MPa,温度35℃,动态萃取时间120 m in,CO2流量1 mL/m in,背压阀温度50℃。此外,还建立了高效液相色谱梯度洗脱分离三萜类化合物的方法。通过比较超临界流体提取物和甲醇提取物的色谱图,发现两者具有相似的峰形,说明超临界流体能够达到与甲醇相近的萃取效果,可以取代甲醇作为新一代的绿色萃取溶剂。     

超临界流体萃取法测定补骨脂中的主要成分

 采用超临界流体萃取(SFE)技术和CGC技术测定了 中药补骨脂中的补骨脂素和异补骨脂素。对超临界流体萃取过程中影响萃取效率的主要因素 采用正交设计法和方差分析法进行了考察,确定了主效应和适宜的操作条件。与传统的萃取 法比较,SFE 具有经济、快速、简便、选择性好、环境污染小等优点。     

超临界流体萃取中草药的研究进展

综述了近二十年来超临界流体萃取技术在中草药提取与分离中的研究现状 ,并展望了其应用前景     

有机锡化合物催化合成应用进展

综述了近二十年来有机锡化合物在催化合成中的应用进展,阐述了有机锡化合物在催化加成,酯化,环化,偶联,聚合等方面的应用,有机锡化合物催化反应条件温和,活性高,有很高选择性,在催化合成领域有广阔的应用前景。     

Selective extraction of strontium with supercritical fluid carbon dioxide

Strontium (Sr(2+)) can be selectively extracted from aqueous solutions into supercritical fluid CO(2) at 60 °C and 100 atm with dicyclohexano-18-crown-6 (DC18C6) using CF(3)(CF(2))(6)CO(2) (-) (PFOA(-)) or CF(3)(CF(2))(6)CF(2)SO(3) (-) (PFOSA(-)) as a counter anion; at a mole ratio of Sr(2+) : DC18C6 : PFOA(-) = 1:10:50, the extraction of Sr (5.6 × 10(-5) M) from water at pH 3 is near quantitative whereas Ca(2+) and Mg(2+) at equal concentration are only extracted to a level of 7 and 1%, respectively; PFOSA(-) is an effective counter anion for selective extraction of Sr(2+) from 1.3 M HNO(3) with DC18C6 in supercritical CO(2).     

Chemicals from forest products by supercritical fluid extraction

Supercritical acetone or methanol extraction of wood gave liquid products with a maximum yield of 74%. Approximately 5% of these complex products was identified as substituted guaiacols and levoglucosan. Acetone extract could substitute for 30% of the phenol in phenolic resins.

Resin and fatty acids were extracted from southern pine and waxes from Douglas-fir bark using supercritical carbon dioxide, nitrous oxide, propane or ethylene. Of these, propane and nitrous oxide gave the best yields.     

超临界二氧化碳萃取秋水仙碱（英文）

 利用超临界二氧化碳对秋水仙块根（经粉碎）中的秋水仙碱进行了萃取,采用高效液相色谱法对萃取出的秋水仙碱的质量分数进行了测定。实验选择40℃20～40MPa作为超临界苹取的操作条件,采用体积分数为95％的乙醇在索氏提取器中对样品进行了对比苹取实验。结果表明:不加浸泡剂进行浸泡处理的样品中的秋水仙碱很难被超临界二氧化碳萃取,在40℃,35MPa条件下,消耗1．28mol的二氧化碳只得到3％的萃取率。加入极少量的有机溶剂浸泡处理样品15min后再进行超临界萃取,可以极大程度地提高秋水仙碱的萃取率。     

Determination of organotin compounds in environmental samples by supercritical fluid extraction and gas chromatography with atomic emission detection

The extraction of six tetraalkyltin and seven ionic organotin compounds from spiked topsoil samples with supercritical carbon dioxide and carbon dioxide modified with 5 percent methanol was investigated. Analysis of the soil extracts was performed by gas chromatography with atomic emission detection. Retention times, minimum detectable concentrations, and detector linear ranges are included for nine organotin compounds (seven of the nine compounds were derivatized with n-pentylmagnesium bromide prior to gas chromatographic analysis). A 2³ factorial experimental design was used to study the effect of three variables (pressure, temperature, and extraction time) on compound recovery. The results indicate that the tetraalkyltin compounds are extracted from topsoil samples with recoveries ranging from 90 to 110 percent. Recoveries for the ionic organotin compounds ranged from 50 to 75 percent for trimethyltin chloride, triethyltin bromide, and tributyltin iodide; they were below 20 percent for dimethyltin dichloride, dibutyltin dichloride, diphenyltin dichloride, and butyltin trichloride. When sodium diethyldithiocarbamate was added to the soil samples prior to extraction, followed by extraction with carbon dioxide modified with 5 percent methanol, recoveries ranged from 70 to 90 percent for trimethyltin chloride, triethyltin bromide, dimethyltin dichloride, tributyltin iodide, and dibutyltin dichloride; recoveries were approximately 40 percent for butyltin trichloride and diphenyltin dichloride.     

Selective extraction of astaxanthin from crustaceans by use of supercritical carbon dioxide

An on-line supercritical fluid extraction (SFE) system coupled to a continuous flow manifold including a UV detector was used as a screening system to extract astaxanthin from crayfish, which was found to be the major carotenoid present in the samples. This compound constitutes the principal additive used to dye salmon flesh. The flow manifold was used to confirm the presence of astaxanthin in the crustacean samples. Also, an HPLC/UV-vis method was used to ascertain that this compound was the major carotenoid extracted under the optimum SFE conditions employed. The influence of SFE operating variables such as pressure, temperature, equilibration time, extraction time, trap temperature, and volume of CO₂ modifier was examined in order to maximize the efficiency of analyte extraction. The use of supercritical CO₂ enables the expeditious, selective, quantitative extraction of astaxanthin from crustaceans.     

Selective extraction of hydrocarbons, phosphonates and phosphonic acids from soils by successive supercritical fluid and pressurized liquid extractions

Hydrocarbons, dialkyl alkylphosphonates and alkyl alkylphosphonic acids are selectively extracted from spiked soils by successive implementation of supercritical carbon dioxide, supercritical methanol-modified carbon dioxide and pressurized water. More than 95% of hydrocarbons are extracted during the first step (pure supercritical carbon dioxide extraction) whereas no organophosphorus compound is evidenced in this first extract. A quantitative extraction of phosphonates is achieved during the second step (methanol-modified supercritical carbon dioxide extraction). Polar phosphonic acids are extracted during a third step (pressurized water extraction) and analyzed by gas chromatography under methylated derivatives (diazomethane derivatization). Global recoveries for these compounds are close to 80%, a loss of about 20% occurring during the derivatization process (co-evaporation with solvent). The developed selective extraction method was successfully applied to a soil sample during an international collaborative exercise.     

Utilization of fat retainers in supercritical fluid extraction for the selective extraction of polychlorinated biphenyls from a model fat sample

Two common fat retainers used in supercritical fluid extraction--basic alumina and the silica based adsorbent Florisil--were investigated using lard fat as model material. With a fat retainer in the extraction cell it was possible to obtain fat-free time windows. Activation by heating did not influence the length of the time windows, while deactivation of the retainers with 10% water (w/w) drastically decreased the fat retaining capabilities. The influence of modifier addition was also investigated. Finally, a method was developed, where basic alumina was utilized to selectively extract polychlorinated biphenyls (PCBs) from a model fat sample, containing PCBs, triglycerides and phospholipids. The PCBs could be quantitatively extracted in a totally fat-free time window.     

Extraction and isolation of diphenylheptanes and flavonoids from Alpinia officinarum Hance using supercritical fluid extraction followed by supercritical fluid chromatography

In this paper, an off-line combination method of supercritical fluid extraction and supercritical fluid chromatography was developed for the selective extraction and isolation of diphenylheptanes and flavonoids from Alpinia officinarum Hance. The enrichment of target components was successfully achieved using supercritical fluid extraction with the following conditions (8% ethanol as co-solvent at 45°C and 30 MPa for 30 min). Taking full advantage of the complementarity of supercritical fluid chromatography stationary phases, a two-step preparative supercritical fluid chromatography strategy was constructed. The extract was firstly divided into seven fractions on a Diol column (250 × 20 mm internal diameter, 10 μm) within 8 min by gradient elution increasing from 5% to 20% modifier (methanol) at 55 ml/min and 15 MPa. Then the seven fractions were separated by using a 1-AA or a DEA column (250 × 19 mm internal diameter, 5 μm) at 50 ml/min and 13.5 MPa. This two-step strategy showed superior separation ability for structural analogs. As a result, seven compounds, including four diphenylheptanes and three flavonoids with high purity, were successfully obtained. The developed method is also helpful for the extraction and isolation of other structural analogs of traditional Chinese medicines.     

Improved supercritical fluid extraction of sulphonamides

Summary Different ways used for enhancing the yield of sulphonamides leached from solid supports are reported. Supercritical CO₂ and methanol-modified CO₂ were used as extractants of the target analytes and the impregnation of the solid sample with buffer, derivatization of the analytes and ion-pair formation were assessed. Only the sulphonamide/tetramethyl-ammonium ion-pairs are quantitatively extracted from the solid supports using pure supercritical CO₂, while the other modifications and the presence of a cosolvent lead to recoveries lower than 30% for most of the analytes. Individual separation/quantitation of the analytes was performed off-line using a liquid chromatograph.