响应面法优化烟草中有机氯农药残留的加速溶剂萃取

采用响应面法(RSM)优化了烟草中有机氯农药残留的加速溶剂萃取(ASE)条件,并利用气相色谱-质谱法进行定性定量分析.以有机氯农药平均回收率为指标,考察了加速溶剂萃取过程中提取溶剂、萃取温度、冲洗溶剂体积、循环次数和吹扫时间等因素对烟草中有机氯提取效果的影响.经响应面优化的最佳ASE条件为:提取溶剂为正己烷-丙酮(体积比9:1),萃取温度107 ℃,冲洗体积92%,吹扫时间92 s,循环次数3次.在优化条件下,烟草有机氯农药萃取回收率理论预测值为96.5%,验证值为94.9%.结果表明,响应面法适用于烟草中有机氯农药残留加速溶剂萃取条件的优化,经优化得到的萃取参数准确可靠,具有实用价值.     

加速溶剂萃取法快速提取黄连中的生物碱

探讨了快速溶剂萃取法（ASE）提取黄连中生物碱的可行性,并比较了该方法与回流提取法和超声提取法的优越性。以黄连中盐酸小檗碱的提取率为指标,以高效液相色谱法（HPLC）为检测方法,用正交实验对快速溶剂萃取法从黄连中提取盐酸小檗碱的工作条件进行优化。最佳仪器参数：提取溶剂为80%乙醇＋0.5%HCl,提取温度为130℃,静态提取时间为10 min,提取次数为1次。快速溶剂萃取法可作为黄连中生物碱分析测定的前处理方法。     

加速溶剂萃取法提取中药材中黄芪甲苷

采用加速溶剂萃取仪(ASE)以甲醇为溶剂提取黄芪药材中的黄芪甲苷,利用高效液相色谱-蒸发光散射检测器(HPLC-ELSD)进行含量测定.考察了不同的提取温度、提取时间、循环次数等条件下的提取效果,确定了最佳的ASE提取条件.同传统的提取方法相比,ASE法溶剂用量少,耗时短,提取效率高.并通过回收率和精密度的测定,证明加速溶剂萃取技术完全可以用于中药材中的黄芪甲苷的提取.     

小叶女贞花挥发性成分分析

采用水蒸汽蒸馏法,分别以正己烷和乙醚为萃取剂从小叶女贞花中提取挥发性成分,结合气相色谱-质谱(GC-MS)法,运用峰面积归一化法计算各化学成分在挥发油中的相对含量.在正己烷萃取的挥发油中鉴定了45种组分,在乙醚萃取的挥发油中鉴定了58种组分.研究了不同极性溶剂作萃取剂对小叶女贞花挥发性成分的影响.     

L-半胱氨酸衍生物配体交换手性色谱固定相

应用密闭微波萃取装置对芦荟中的有效成分芦荟甙进行了微波萃取研究,并利用透射电子显微镜对微波萃取机理进行了初步探讨,讨论了不同萃取剂、溶剂浓度、萃取时间和微波功率等对提取率的影响,在萃取剂为乙醇-水体系,溶剂（乙醇）体积分数为70％、萃取时间为4min及微波功率为340W的条件下,萃取效果最佳,与索氏提取及超声波萃取法相比,本法具有萃取速度快、提取率高及溶剂用量少等特点。     

加速溶剂提取-高效液相色谱法测定甘草中甘草酸的含量

采用加速溶剂提取法(ASE)提取甘草中有效成分甘草酸,高效液相色谱(HPLC)法测定其含量,探索ASE法提取甘草酸的最佳工艺条件,寻找一种快速、高效测定甘草中甘草酸含量的新方法.结果表明,ASE法提取甘草酸的最佳工艺条件为:提取温度为60℃,提取3次,每次静态提取时间为15 min,提取率高达2.15%.ASE-HPLC法是一种准确、快速测定甘草酸含量的新方法.     

ASE-HPLC检测某型号球形发射药中的叠氮硝胺、硝化甘油、Ⅱ号中定剂含量的研究

采用快速溶剂萃取（ASE）技术和高效液相色谱法测定某球形药中叠氮硝胺（DIANP）、硝化甘油（NG）和Ⅱ号中定剂（C2）的含量．ASE提取条件：二氯甲烷做萃取溶剂,萃取温度100℃,静态萃取10min,萃取2次．HPLC测定条件：YWGC18柱（150×4．6mm,10μm）,以甲醇和水作为流动相,梯度洗脱,流速1 mL／min,检测波长210nm．测定结果表明DIANP、NG、C2平均回收率分别为99．6％、100．3％、99．4％,RSD分别为0．7％、0．8％、0．9％（n=5）,检出限分别为2.1、1.5和0．2mg／L,线性范围分别为0．02～0．98g／L,0．03～1．38g／L,0．002～0．124g／L．用此方法共检测某批球形发射药样品5份,检测结果与滴析-HPLC法检测结果相当．     

加速溶剂萃取-同位素质谱分析土壤水的氢氧同位素

土壤水是水循环的重要组成部分,其氢氧同位素组成在生态学、环境学、水文学等领域有着广泛应用。不同的提取水方法存在较大偏差,因此本研究建立了加速溶剂萃取(ASE)提取-同位素质谱(IRMS)分析土壤水中氢氧同位素的方法。ASE提取土壤水的条件是:萃取溶剂二氯甲烷,萃取温度100℃,萃取压力10.3 MPa,静态萃取时间10 min,重复提取3次,循环次数分别为4,4和3次,合并提取土壤水并经活性炭固相萃取柱(SPE)净化后,利用同位素比质谱分析土壤水的氢氧同位素组成。与过注水相比,提取土壤水的δD增加2.12‰~4.58‰,δ18O增加-0.17‰~0.93‰,氢氧同位素的分析精度分别为0.89‰和0.37‰。     

加速溶剂萃取/气相色谱-质谱测定海洋沉积物中的痕量多环芳烃

沉积物是多环芳烃(polycyclic aromatic hydrocarbons,PAHs)在环境中迁移归趋的一个重要的汇[1]。沉积物中多环芳烃的提取方法主要有索氏提取、超声波提取、微波萃取、加速溶剂提取及超临界流体萃取等。其中加速溶剂提取(accelerated solvent extraction,ASE)由于提取速度快,溶     

加速溶剂萃取法提取海洋沉积物中正构烷烃的方法研究

采用加速溶剂萃取法(ASE)提取了海洋沉积物中的正构烷烃,并对ASE的萃取剂比例、萃取温度、静态萃取时间以及循环次数等实验条件进行优化。结果表明,当样品长碳链正构烷烃含量较高或需要检测长碳链正构烷烃含量时,可使用甲醇-二氯甲烷(1∶3)作为萃取剂;而甲醇-二氯甲烷(1∶9)适用于短碳链正构烷烃含量较高或需要检测短碳链正构烷烃含量的样品。加速溶剂萃取提取沉积物中正构烷烃的最佳条件为:萃取温度150℃,静态提取时间15 min,循环3次。在优化条件下,测定沉积物样品中正构烷烃的精密度除C15为20%外,其余为3%~14%,替代物回收率为84%~114%。相比于传统的索氏提取法,该方法的工作效率高、回收率高、精密度良好,适用于沉积物样品中正构烷烃的定量分析。     

Accelerated solvent extraction of fluometuron from selected soils

Accelerated solvent extraction (ASE) is a recently developed extraction technique that is more rapid and produces less waste than do conventional liquid/liquid extraction methods. Optimal conditions were determined for ASE of fluometuron from 2 Weswood clay loam soils. Two solvents (acetonitrile and methanol), 2 temperatures (50 and 100 degrees C), and the number of static cycles (1, 2, and 3) were evaluated. The most efficient and reproducible extractions were obtained when methanol was combined with a 50 degrees C extraction temperature and the static cycle was repeated 3 times. These experiments indicated that existing extraction methods for fluometuron can easily be adapted for ASE.     

Characterization of secondary volatile profiles in Nigella sativa seeds from two different origins using accelerated solvent extraction and gas chromatography-mass spectrometry

The extraction and identification of bioactive compounds from herbs is of great interest. In this study, accelerated solvent extraction (ASE) technique was used to analyze the secondary volatile profiles in Nigella sativa seeds obtained from two different origins, Egypt and Bangladesh. The main extraction parameters, including extraction temperature, pressure and static extraction time, were investigated and optimized. Identification and quantification of the major constituents in nonpolar extracts (hexane) were achieved by means of GC‐FID/GC‐MS analysis with external standards. The two seeds showed a similar variety of chemical composition; however, the secondary volatiles profile of Bangladesh seed was higher than that of the Egyptian seed. A total of 25 compounds were identified from the ASE extract under the following optimum extraction conditions: 100°C, 1500 psi and 5 min, for extraction temperature, pressure and static time, respectively. The proposed technique can be used for the characterization of N. sativa varieties or cultivars. Copyright © 2012 John Wiley & Sons, Ltd.     

Extraction and detection of arsenicals in seaweed via accelerated solvent extraction with ion chromatographic separation and ICP-MS detection

An accelerated solvent extraction (ASE) device was evaluated as a semi-automated means of extracting arsenicals from ribbon kelp. The effect of the experimentally controllable ASE parameters (pressure, temperature, static time, and solvent composition) on the extraction efficiencies of arsenicals from seaweed was investigated. The extraction efficiencies for ribbon kelp (approximately 72.6%) using the ASE were fairly independent (< 7%) of pressure, static time and particle size after 3 ASE extraction cycles. The optimum extraction conditions for the ribbon kelp were obtained by using a 3 mL ASE cell, 30/70 (w/w) MeOH/H2O, 500 psi (1 psi = 7 KPa), ambient temperature, 1 min heat step, 1 min static step, 90% vol. flush, and a 120 s purge. Using these conditions, two other seaweed products produced extraction efficiencies of 25.6% and 50.5%. The inorganic species present in the extract represented 62.5% and 27.8% of the extracted arsenic. The speciation results indicated that both seaweed products contained 4 different arsenosugars, DMA (dimethylarsinic acid), and As(V). One seaweed product also contained As(III). Both of these seaweed products contained an arsenosugar whose molecular weight was determined to be 408 and its structure was tentatively identified using ion chromatography-electrospray ionization-mass spectrometry/mass spectrometry (IC-ESI-MS/MS).     

Extraction and detection of arsenicals in seaweed via accelerated solvent extraction with ion chromatographic separation and ICP-MS detection

An accelerated solvent extraction (ASE) device was evaluated as a semi-automated means of extracting arsenicals from ribbon kelp. The effect of the experimentally controllable ASE parameters (pressure, temperature, static time, and solvent composition) on the extraction efficiencies of arsenicals from seaweed was investigated. The extraction efficiencies for ribbon kelp (approximately 72.6%) using the ASE were fairly independent ¶(< 7%) of pressure, static time and particle size after 3 ASE extraction cycles. The optimum extraction conditions for the ribbon kelp were obtained by using a 3 mL ASE cell, 30/70 (w/w) MeOH/H₂O, 500 psi (1 psi = 7 KPa), ambient temperature, 1 min heat step, 1 min static step, 90% vol. flush, and a 120 s purge. Using these conditions, two other seaweed products produced extraction efficiencies of 25.6% and 50.5%. The inorganic species present in the extract represented 62.5% and 27.8% of the extracted arsenic. The speciation results indicated that both seaweed products contained 4 different arsenosugars, DMA (dimethylarsinic acid), and As(V). One seaweed product also contained As(III). Both of these seaweed products contained an arsenosugar whose molecular weight was determined to be 408 and its structure was tentatively identified using ion chromatography-electrospray ionization-mass spectrometry/mass spectrometry (IC-ESI-MS/MS).     

Application of accelerated solvent extraction to the investigation of saikosaponins from the roots of Bupleurum falcatum

Accelerated solvent extraction (ASE) was applied to the extraction of saikosaponin a, saikosaponin c and saikosaponin d from the roots of Bupleurum falcatum. Main extraction parameters such as the extraction solvents, extraction temperature and static extraction time were investigated and optimized. The optimized procedure employed 70% methanol as extraction solvent, 120°C of extraction temperature, 10 min of static extraction time, 60% of flush volume and the extraction recoveries of the three compounds were near to 100% with one extraction cycle. The extracted samples were analyzed by HPLC with UV detector. The HPLC conditions were as follows: Hypersil ODS2 (4.6 mm×250 mm, 5 μm) column, acetonitrile and water as mobile phase, flow rate of 1.0 mL/min, UV detection wavelength of 204 nm and injection volume of 20 μL. Compared with the traditional methods including heat‐reflux extraction and ultrasonic‐assisted extraction, the proposed ASE method was more efficient and faster to be operated. The results indicated that ASE was an alternative method for extracting saikosaponins from the roots of B. falcatum.     

Optimization of pressurized liquid extraction (PLE) of dioxin-furans and dioxin-like PCBs from environmental samples

Pressurized liquid extraction (PLE) applying three extraction cycles, temperature and pressure, improved the efficiency of solvent extraction when compared with the classical Soxhlet extraction. Polychlorinated-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like PCBs (coplanar polychlorinated biphenyls (Co-PCBs)) in two Certified Reference Materials [DX-1 (sediment) and BCR 529 (soil)] and in two contaminated environmental samples (sediment and soil) were extracted by ASE and Soxhlet methods. Unlike data previously reported by other authors, results demonstrated that ASE using n-hexane as solvent and three extraction cycles, 12.4 MPa (1800 psi) and 150 degrees C achieves similar recovery results than the classical Soxhlet extraction for PCDFs and Co-PCBs, and better recovery results for PCDDs. ASE extraction, performed in less time and with less solvent proved to be, under optimized conditions, an excellent extraction technique for the simultaneous analysis of PCDD/PCDFs and Co-PCBs from environmental samples. Such fast analytical methodology, having the best cost-efficiency ratio, will improve the control and will provide more information about the occurrence of dioxins and the levels of toxicity and thereby will contribute to increase human health.     

Dispersive solid-phase extraction cleanup combined with accelerated solvent extraction for the determination of carbamate pesticide residues in Radix Glycyrrhizae samples by UPLC-MS-MS

Dispersive solid-phase extraction (DSPE) cleanup combined with accelerated solvent extraction (ASE) is described here as a new approach for the extraction of carbamate pesticides in Radix Glycyrrhizae samples prior to UPLC-MS-MS. In the DSPE-ASE method, 15 carbamate pesticides were extracted from Radix Glycyrrhizae samples with acetonitrile by the ASE method at 60 °C with a 5 min heating time and two static cycles. Cleanup of a 1 mL aliquot of the extract by the DSPE method used 20 mg PSA (primary secondary amine), 50 mg Al(2)O(3)-N, and 20 mg GCB (graphitized carbon black) (as cleanup sorbents) under the determined optimum conditions. The linearity of the method was in the range of 10 to 200 ng/mL with correlation coefficients (r(2)) of more than 0.996. The limits of detection were approximately 0.2 to 5.0 μg/kg. The method was successfully used for the analysis of target pesticides in Radix Glycyrrhizae samples. The recoveries of the carbamate pesticides at the spiking levels of 50, 100, and 200 μg/kg ranged from 79.7% to 99.3% with relative standard deviations lower than 10%. This multi-residue analytical method allows for a rapid, efficient, sensitive and reliable determination of target pesticides in Radix Glycyrrhizae and other medicinal herbs.     

Comparison of different extraction techniques for the determination of chlorinated pesticides in animal feed

The performances of Soxhlet extraction, dive-in Soxhlet extraction, microwave-assisted extraction (MAE), accelerated solvent extraction (ASE), fluidized-bed extraction (FBE), and ultrasonic extraction (UE) for the analysis of organochlorine pesticides in animal feed have been investigated. ASE and MAE provided significantly better extraction efficiency than Soxhlet extraction. The concentrations were 126.7 and 114.8%, respectively, of the values obtained by classical Soxhlet extraction, whereas the results from FBE and dive-in Soxhlet were comparable with those from the standard Soxhlet procedure. The reproducibility of FBE was the best, with RSDs ranging from 0.3 to 3.9%. Under the investigated operation conditions UE was not efficient, with the recoveries of target compounds being about 50% less than Soxhlet. Additionally, the performances of Soxhlet, dive-in Soxhlet, MAE, ASE and FBE were validated by determination of the certified reference material BCR-115. The results from the extraction techniques were in good agreement with the certified values.     

加速溶剂萃取/气相色谱-负化学电离质谱法对土壤中毒杀芬的测定研究

建立了加速溶剂萃取/气相色谱-负化学电离质谱法测定土壤中毒杀芬的方法.在加速溶剂萃取实验条件优化的基础上,确定了最佳实验条件:系统压力12.4 MPa,萃取溶剂为正己烷-丙酮(体积比1 : 1),萃取温度100 ℃,静态萃取时间10 min,循环2次.萃取液经活性炭与弗罗里硅土复合小柱净化后,氮吹至1.0 mL,于GC-MS仪上测定.结果表明,毒杀芬的线性范围为0.3 ～3 000 ng/g(毒杀芬总量),相关系数均不小于0.999 0,方法检出限为0.10 ～1.00 ng/g,平均回收率为86% ～104%,相对标准偏差(n=7)为6.8% ～13.5%.