阿魏酸和川芎嗪在超临界CO2中溶解度的测定

采用动态法分别测定了阿魏酸和川芎嗪在超临界CO2中的溶解度.实验结果表明在压力10～35MPa和温度308.15～338.15K范围内,阿魏酸在超临界CO2中的溶解度(摩尔分数)为6.936×10(7～26.527×10(7;在压力10～30MPa和温度318.15～338.15K范围内,川芎嗪在超临界CO2中的溶解度(摩尔分数)为0.010～0.131.阿魏酸在超临界CO2中的溶解度随着压力的增加而增大;温度对阿魏酸溶解度的影响较为复杂,出现了交迭压力行为.而川芎嗪在超临界CO2中的溶解度在实验范围内没有出现交迭压力行为.采用Chrastil方程分别对阿魏酸和川芎嗪在超临界CO2中的溶解度数据进行了关联,其AARD值分别为12.92%和4.23%.     

对羟基苯甲酸甲酯在含夹带剂超临界CO2中溶解度的研究

采用流动法测定了对羟基苯甲酸甲酯在含和不舍夹带剂的超临界CO2中的溶解度,实验所用夹带剂分别为正己烷、乙醇、丙酮及混合夹带剂正己烷 丙酮(摩尔比为1：1),夹带剂的摩尔分数均为0．035。论述了温度、压力和夹带剂对固体溶解度的影响,然后用化学缔合模型关联了实验数据,实验值与计算值吻合良好。     

β-石竹烯、对伞花烃及3-蒈烯二元体系的超额焓

利用C80型Calvet微量量热仪测定了对伞花烃+β-石竹烯,3-蒈烯+β-石竹烯和3-蒈烯+对伞花烃三个二元体系在298.15 K下的超额焓。三个二元体系的超额焓数据在全浓度范围内均为正值,并且最大值均在摩尔分数x1=0.5附近。采用Redlich-Kister方程对实验数据进行关联,标准偏差分别为0.2151、0.1773和0.4483 J·mol~(-1)。结果表明实验所测定的超额焓与关联结果吻合较好。在相同温度下,3-蒈烯+对伞花烃体系的超额焓值均大于含重质松节油组分的对伞花烃+β-石竹烯和3-蒈烯+β-石竹烯体系。     

响应面分析法优化依兰香提取β-石竹烯工艺

在单因素试验基础上,以压力、时间、温度为响应因子,以β-石竹烯提取率为响应值,采用响应曲面法进行工艺优化预测,对依兰香中β-石竹烯的超临界CO2提取工艺进行优化。试验表明,影响β-石竹烯提取率的各因素的影响力由大到小顺序为压力、温度、时间,最佳提取工艺条件为提取压力369 MPa、提取温度60℃、提取时间4 h,此时β-石竹烯提取率为0.903 8%。验证试验结果与模型预测值基本相符,表明该工艺可用于依兰香中β-石竹烯的提取。     

超临界CO2及超临界CO2/乙醇中磷脂酰胆碱的溶解度

利用动态法测定了磷脂酰胆碱(PC)在超临界CO2(SC-CO2)及超临界CO2/乙醇体系中的溶解度。在15~30 MPa压力(p)、313~343 K温度(T)条件下,PC在SC-CO2中的溶解度为x1(PC)=10-6~10-5,在SC-CO2/乙醇多元体系中,PC溶解度x2(PC)可提高至10-4。PC的溶解度与c(CO2)(d)、x(CH3CH2OH)(c)呈指数相关性。根据缔合反应规则,建立了质量作用模型x1(PC)=d3.89e(-2383.63/T-41.64)、x2(PC)=d3.17c0.36e(-1748.03/T-33.73),分别关联PC在SC-CO2、SC-CO2/乙醇中的溶解度,模型计算结果与溶解度实验数据较好吻合,关联误差(AARD)分别为4.31%、3.78%。     

超临界CO2技术分离提纯青蒿挥发油及成分分析

用超临界CO2流体萃取技术(SFE)制得青蒿油浸膏,然后用分子蒸馏技术(MD)进行精制。超临界CO2流体萃取青蒿精油最佳工艺条件为:萃取压力25 MPa,温度50℃,CO2流量25 kg/h,萃取时间3 h;分子蒸馏温度为80~120℃,所得青蒿油呈淡黄色,得率由传统水蒸气蒸馏法的0.13%提高到0.47%;所得精油经GC-MS分析,检测出60种成分,主体呈香成分为柠檬烯、(1S)-α-蒎烯、β-蒎烯、β-金合欢烯、α-石竹烯、γ-榄香烯等烯类,精油质量标准达到FCC(2006)。     

超临界CO2中固体溶解度的逆向传播人工神经网络模拟

为了更好地模拟超临界CO2(SC CO2)中固体的溶解度数据,采用逆向传播神经网络(BPANN)对30种固体在超临界CO2中的873个溶解度数据进行了模拟,所得相对误差(AARD)都在10%以下,小于状态方程和经验方程的值,此结果表明BPANN能较好地模拟SC CO2中固体的溶解度数据。     

分散橙30和分散橙31在超临界CO2中的溶解度测定

超临界CO2染色技术是一种新型的无水染色技术,染料在超临界CO2中的溶解度是超临界CO2染色工艺的一个重要基础数据.在压力16～28 MPa、温度343.2～383.2 K范围内,采用静态循环法对分散橙30和分散橙31两种分散染料在超临界CO2中的溶解度进行了测定.两者的溶解度范围分别为2.1×10-5～7.8×10-5和1.4×10-5～3.7×10-5(摩尔分率),均随着压力的升高而升高.由溶解度随温度变化趋势推测,分散橙30在16 MPa附近将出现压力转折点,而分散橙31在实验范围内未出现转折压力.两种染料的溶解度数据比较表明,苯环上引入-Cl,可使溶解度明显提高.分散橙30和分散橙31的溶解度实验数据用Chrastil经验模型拟合,平均相对偏差分别为4.9%和2.46%.     

溢流法测定超临界CO_2在聚己酸内酯中的溶解

以超临界CO2作为溶剂,采用溢流法研究聚己酸内酯(PCL)在CO2中的溶胀过程和超临界CO2/PCL体系的热力学平衡规律。考察了温度、压力对溶解度的变化趋势,分析加入有机溶剂后对CO2在聚合物中的溶解度的影响,并应用P-T(Patel-Teja)方程作为热力学模型分析和计算溶解规律。结果表明:CO2的溶解度随温度升高而降低,随压力增大而增大,有机溶剂的加入能够进一步提高CO2的溶解度,在相同的温度压力条件下,加入相当于CO2质量的2.26%的二氯甲烷,最多可使溶解度增加28.06%。在温度313.15—353.15 K、压力10—20 MPa范围内,P-T方程能较好地预测CO2在PCL中的溶解度,其相对误差在-12.53%—12.01%。     

CO_2在混合胺MEA+DETA溶液中的溶解度

在温度298—338 K,压力300—700 kPa,吸收剂浓度1—3 mol/L的实验条件范围内,讨论了CO2-吸收剂体系气液二相基本达到平衡时,CO2吸收量与体系温度,压力及吸收剂浓度的关系。根据亨利定律,引入温度及压力相关因子,建立了CO2在单胺溶液中的溶解度模型。模型对CO2在MEA、DETA单胺溶液中的溶解度预测效果较好,与实验值比较,误差在1%以下。引入增强因子β=1.06,并以单胺在混合胺溶液中的摩尔分数为系数,将CO2在单胺溶液中的溶解度叠加获得CO2在MEA+DETA混合溶液中的溶解度模型。模型对MEA+DETA混合胺的预测误差在1%—10%。     

川芎油在超临界二氧化碳中溶解度的测定与关联

Extraction of the Ligusticum Chuanxiong oil with supercritical CO2 （SC-CO2） was investigated at the temperatures ranging from 55℃ to 70℃ and pressure from 25 MPa to 35 MPa. The mass of Ligusticum Chuanxiong oil extracted increased with pressure at constant temperature. The initial slope of the extraction was considered as the solubility of oil in SC-CO2. Chrastil equation was used to correlate the solubility data of Ligusticum Chuanxiong oil. An improved Chrastil equation was also presented and was employed to correlate the solubility data, The correlation results show that the values of the average absolute relative deviation are 5.94% and 3.33% respectively, indicating the improved version has better correlation accuracy than that of Chrastil equation.     

Estimation of solubility of solids in supercritical carbon dioxide

Peng-Robinson equation of state(PR EOS)was chosen for modeling the thermodynamic be-havior of supercritical(SC)-CO_2/Solid systems.The necessary critical constants and acentric factorof the solute were obtained by the Sigmund and Trebble(1992)method based on the molecular weightand boiling temperature,and the vapor pressure of the solute was calculated by its meltingtemperature and heat of fusion.This approach compared very favorably with the conventional corres-ponding state theory,but without using critical constants and vapor pressure of solutes.Four mixingrules were tested for the calculation of solid solubility in SC-CO_2.van der Waals(vdW)mixing rulewith one parameter was considered to be most suitable for the estimation of solubility.A simplecorrelation was developed for the SC-CO_2/solid binary interaction coefficient k_(ij) with the meltingtemperature of pure solutes.The solubilities of solids in SC-CO_2 were estimated for eleven binarysystems at various temperatures,the total absolute average     

Solubility of chlorpheniramine maleate in supercritical carbon dioxide

Solubility of chlorpheniramine maleate in supercritical carbon dioxide at different temperatures (308–338 K) and pressures (160–400 bar) is measured using static method coupled with gravimetric method. The measured solubility data demonstrated that the solubility of chlorpheniramine maleate was changed between 1.54 × 10⁻⁵ and 4.26 × 10⁻⁴ based on the mole fraction as the temperature and pressure are changed. The general trend of measured solubility data shows a direct effect of pressure and temperature on the solubility of chlorpheniramine maleate. Finally, the obtained solubilities correlated using four semi-empirical density-based correlations including Mendez Santiago–Teja (MST), Kumar and Johnston (KJ), Bartle et al., and Chrastil models. Although the results of modeling showed that the KJ model leads to the average absolute relative deviation percent (AARD %) of 8.1% which is the lowest AARD %, deviation of other utilized correlations are rather the same.     

Solubility model of arachis hypogea skin oil by modified supercritical carbon dioxide

The main objective of this study was to determine the solubility of peanut (Arachis Hypogea) skin oil using modified supercritical carbon dioxide (SCCO₂). The solubility was measured at pressure ranging from 100 to 300 Bar, temperature of 313 to 328 K, and rate of modifier from 0.075 to 0.225 mL/min. The solubility of extraction was ranging from 1.12 to 7.73 mg/min. The Chrastil, modified Chrastil, Del Valle Aguilera (DVA), Adachi-Lu, and Gordillo as empirical models were tested to fit the experimental data. Solubilities from these models followed the average absolute relative deviations (AARD) from experimental data: Chrastil, modified Chrastil, DVA, Adachi-Lu, and Gordillo with AARD of 8.54%, 8.26%, 19.41%, 9.24%, and 20.62%, respectively. Modified Chrastil model provide the best fit.     

Experimental investigation and modeling of the solubility of carvedilol in supercritical carbon dioxide

This study was aimed to measure the solubility of carvedilol in the temperature and pressure ranges of 308⿿338 K and 160 bar to 400 bar, respectively. In this direction, a homemade high pressure visual equilibrium cell was used to measure the solubility of carvedilol using a static method coupled with gravimetric technique. The results revealed that the carvedilol solubility was ranged between 1.12 ÿ 10^⿿5 and 5.01 ÿ 10^⿿3 based on the mole fraction (mole of carvedilol/mole of carvedilol + mole of CO₂) in this study as the temperature and pressure was changed. Finally, the results were correlated using four density-based semi-empirical correlations including Chrastil, Mendez⿿Santiago⿿Teja (MST), Bartle et al., and Kumar and Johnston (K-J) models. Results revealed that although the K-J model leads to the lowest average absolute relative deviation percent (AARD %) of 6.27%, but it could not be considered as the most accurate correlation since all the used four correlations introduces AARD % of about 6⿿10% which may be in the same range as the experimental error.     

Effect of menthol as solid cosolvent on the solubility enhancement of clozapine and lamorigine in supercritical CO2

The solubilities of mixed clozapine and menthol also lamotrigine and menthol in supercritical carbon dioxide were determined at 313 and 323 K and over pressure ranging from 123 to 337 bar. The solubility of both solutes with solid cosolvent system is observed to increase relative to the value of the corresponding without solid cosolvent system. As compared with their respective binary system (without solid cosolvent), the mixed clozapine (with solid cosolvent) solubility enhancement greatly by around 56 times and the lamotrigine one does by approximately eight times. In presence of menthol these chemicals have solubilities with values ranging from 1.88 × 10⁻⁴ to 4.48 × 10⁻⁴ (clozapine) and 0.09 × 10⁻⁴ to 0.36 × 10⁻⁴ (lamotrigine) mole fraction. The solubility data were correlated using five semi-empirical density-based models (Chrastil, Bartle, K-J, M-T and Thakur models). Correlated results for clozapine with the Chrastil, M-T, K-J, and Bartle models and for lamotrigine with the Chrastil, M-T and Bartel models are in excellent agreement with the experimental data.     

不同产地丁香花蕾油的提取及GC-MS分析

采用水蒸气蒸馏法从不同产地的丁香花蕾中提取精油,各自的得油率分别为：印尼11.07%、马达加斯加13.83%、印度13.32%和越南12.04%。采用GC-MS法分析丁香花蕾油的主要成分,结果为：β-石竹烯、丁香酚和乙酸丁香酚酯在这四个产地的丁香花蕾油中相对含量（峰面积相对百分比）之和都达到90%以上,分别为：印尼97.00%、马达加斯加93.74%、印度93.83%和越南97.33%。比较了不同产地丁香花蕾油的香气特征,并探讨了香气差异的原因。     

Solubility of gabapentin in supercritical carbon dioxide

The purpose of this study was to measure the solubility of gabapentin in supercritical carbon dioxide at different pressures and temperatures of 16–40 MPa and 308–338 K, respectively. The measured solubility data revealed that solubility of gabapentin was 8.97 × 10⁻⁵–7.36 × 10⁻³ based on the mole fraction in supercritical carbon dioxide at the aforementioned operational conditions. At last, the obtained results were correlated using four density based semi-empirical correlations namely Bartle et al., Mendez-Santiago and Teja (MST), Chrastil and Kumar and Johnston (K–J). The results revealed that according to the obtained average absolute relative deviations (AARD) for the used density based correlations of MST (AARD % = 9.88%), Chrastil (AARD % = 9.47%), K–J (AARD % = 11.5%) and Bartle et al. (AARD % = 9.29%), none of the correlations can be considered as the most accurate one. In other words, all the examined semi-empirical correlations are in the same level of accuracy.     

Solubility analysis of clozapine and lamotrigine in supercritical carbon dioxide using static system

The experimental techniques used to obtain the solubilities of clozapine and lamotrigine in supercritical carbon dioxide include a simple static technique. The solubility measurements were performed at temperatures between 318 and 348 K and pressures between 121.6 and 354.0 bar. These chemicals have solubilities with values ranging from 3.6 × 10⁻⁶ to 4.2 × 10⁻⁵ (clozapine) and 1 × 10⁻⁶ to 6 × 10⁻⁵ (lamotrigine) mole fraction. The solubility data were correlated using four semi-empirical density-based models (Chrastil, Bartle, K-J and M-T models). Correlation of the results shows good self-consistency of the data obtained with the Bartle model for clozapine with an overall average absolute relative deviation (AARD%) of 11.21. The calculated results with each four models show satisfactory agreement with the experimental data for lamotrigine with an overall AARD% 11.72, 8.99, 2.75, 3.86 for Chrastil, K-J, Bartle, M-T models, respectively. Using the correlation results, the heat of drug-CO₂ solvation and that of drug vaporization were approximated.