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.     

快速溶剂萃取反相高效液相色谱法测定青蒿中的青蒿素

报道了一种应用快速溶剂萃取、经衍生化处理后用RP-HPLC测定青蒿药材中青蒿素的方法。青蒿样品用无水乙醇萃取剂在90℃,12.6 MPa压力下萃取10 min,用碱衍生化后,色谱测定,回收率在95.3%~101.2%。色谱分析条件采用Diamonsil C18色谱柱(250 mm×4.6 mm,5μm),甲醇-0.02 mol/L乙酸铵为流动相,梯度:甲醇体积分数20%~35%,5 min;35%~98%,5 min;98%,6 min,检测波长260 nm;流速:1.0 mL/min;柱温:25℃。结果表明该法准确、重现性好,可以为青蒿质量标准的制订提供科学依据。     

非水毛细管电泳测定黄连饮片中5种生物碱

建立了一种非水毛细管电泳(NACE)同时测定黄连饮片生品与炮制品中小檗碱、巴马汀、药根碱、木兰碱和黄连碱含量的方法。分别考察了非水溶剂、缓冲液体系及其浓度和pH、运行电压、运行温度和检测波长等条件对实验结果的影响。在优化的实验条件下,选择非水毛细管电泳分离模式,以40 mmol/L乙酸钠-40 mmol/L乙酸铵的无水甲醇缓冲溶液(pH 5.8)为电泳介质,未涂渍标准熔融石英毛细管(64.5 cm×75 μm,有效长度56 cm)为分离通道,检测波长为254 nm,分离电压为25 kV,压力进样(5 kPa×6 s),柱温为20 ℃。结果显示,5种生物碱在20 min内可实现基线分离,加标回收率为98.37%～101.03%。该方法简单、准确,重现性较好,可用于黄连饮片内在质量的评价和控制。     

高效毛细管电泳测定黄连及成药中小檗碱型生物碱的含量

报道了黄连及成药中七种小檗碱型生物碱的高效毛细管电泳分离测定方法。缓冲液由６５％磷酸氢二钠（用磷酸调ｐＨ７．０）和１５％甲醇组成。方法具有良好的精密度、回收率及线性关系。并用此法定量测定了黄连及六种成药中三种生物碱（小檗碱、巴马汀、药根碱）的含量。     

加速溶剂萃取法与索氏提取法对废线路板中二噁英测定的影响

将经过多级破碎分选所得的废线路板粉末过60目筛,以2 mol/L HCl溶液、超纯水洗涤,并用丙酮脱水.将预处理后的滤渣、滤纸填入萃取池,或者用新滤纸包裹后置于索氏提取管内,添加5 μL内标物,分别用加速溶剂萃取法(ASE)或索氏提取(SE)法进行萃取,依次采用多层硅胶柱和活性炭柱对萃取提取物进行净化、洗脱,得到二噁英测试样品.用同位素稀释-高分辨气相色谱-质谱联用仪分析样品中二噁英的含量.考察两种提取方法及不同氯代数对15种13C-2,3,7,8-PCDD/Fs回收率的影响,比较两种方法的准确度和精密度.结果表明,ASE和SE对15种13C-2,3,7,8-PCDD/Fs的回收率分别为54.3%~113.0%和28.3%~77.7%, 实测废线路板中二噁英毒性当量(Toxic equivalent quangtity,TEQ)分别为0.075 ng TEQ/kg和0.266 ng TEQ/kg.在方法精密度允许范围内,ASE相对具有简单快速、溶剂用量少和准确的优势.     

分子印迹搅拌棒提取-HPLC法测定黄柏中的盐酸小檗碱

以铁丝为磁芯,盐酸小檗碱为目标分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂聚合成分子印迹搅拌棒,并对搅拌棒的制备条件和测定条件进行了选择。用该搅拌棒提取黄柏中的盐酸小檗碱,并用高效液相色谱法进行测定。盐酸小檗碱质量浓度在10~125 mg/L之间与峰面积A呈良好的线性关系,线性回归方程为:A=3.07×103ρ+1.27×106,相关系数r为0.9993,检出限为2.7 mg/L。加样回收率在94.5%~103.5%之间,RSD为3.3%。     

黄连生物碱的反相高效液相-电喷雾离子阱串联质谱的研究

采用反相高效液相-电喷雾离子阱串联质谱法对由乙醇提取的黄连生物碱进行了研究.优化出了反相高效液相色谱分离黄连生物碱的条件:流动相为V(乙腈):V(H2O)(三乙胺2 mmol/L)=30:70;柱温为30℃;流速为0.5 mL/min,并结合电喷雾串联质谱检测出了黄连生物碱中的小檗碱、药根碱、巴马汀、黄连碱以及微量的表...     

快速溶剂萃取-超高效液相色谱法分析鱼肉中喹乙醇

以甲醇为溶剂,采用ASE快速、高压萃取鱼肉中喹乙醇,并实施了自动在线净化过滤,色谱分析采用了乙醇(色谱级)为流动相,超快速液相色谱法进行分析。喹乙醇的标准工作溶液的线性回归方程为y=0.0358x+0.0019,相关系数r=0.9999,线性范围为0.1～2.0μg/mL,方法检出限(以信噪比(S/N=3)计算)为5.0μg/kg,样品加标回收率平均值(n=3)为88%,同时对6个平行样进行精密度试验,保留时间与峰面积的RSD值分别为0.21%和2.0%,重现性较好。方法可以用来快速分析鱼肉等样品中的喹乙醇。     

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。     

反相高效液相色谱法同时测定黄连中巴马亭及小檗碱的含量

采用反相高效液相色谱法同时测定黄连中巴马亭及小檗碱的含量,色谱条件:ODSC18色谱柱(4.6mm×250mm);流动相为乙腈∶0.05mol/L磷酸二氢钠水溶液(pH2.5)=30∶70(V/V);流速0.6mL/min;测定波长268nm.巴马亭和小檗碱的回归方程分别为C=1.696×10-5A+0.8401,R2=0.9999;RSD=0.015%和C=1 580×10-5A+0.5114,R2=0.9999,RSD=0.14%.回收率分别为99.09%～101.30%和98.96%～101.86%.此方法准确、快速、简单.     

Analysis of alkaloids in Coptis chinensis Franch by accelerated solvent extraction combined with ultra performance liquid chromatographic analysis with photodiode array and tandem mass spectrometry detections

A new method based on accelerated solvent extraction (ASE) followed by ultra performance liquid chromatography (UPLC) analysis has been developed for the identification and quantification of major alkaloids in extracts of Coptis chinensis Franch. The UPLC system consisted of a dual detection system of photodiode array detector (PDA) and positive ion electrospray ionization-tandem mass spectrometry (ESI-MS/MS) in sequential configuration. The operational parameters of ASE including extraction solvent, extraction temperature, static extraction time and extraction cycles were optimized. UPLC analysis was performed on an ACQUITY UPLC BEH C₁₈ column eluted by a mobile phase of acetonitrile spiked with a buffer solution consisting of 0.50% acetic acid and 20 mmol L⁻¹ ammonium acetate. A tandem quadrupole spectrometer operating in either full scan mode or in MS/MS mode for multiple reaction monitoring (MRM) was used for the identification and quantitative analysis of eight major alkaloids in C. chinensis Franch extracts. The samples were also analyzed on a high-performance liquid chromatography-electrospray ionization-time-of-flight mass spectrometry (HPLC-ESI-TOF-MS) system to confirm the identification results. Three of the eight major alkaloids, berberine, palmatine and jatrorrhizine were quantified by UPLC-PDA and UPLC-MS/MS. The results indicated that both UPLC-PDA and UPLC-MS/MS methods were simple, sensitive and reliable for the determination of alkaloids in C. chinensis Franch. Seven Huanglian samples from different locations were analyzed using the established methods. UPLC fingerprints based on the distribution of the eight major alkaloids can serve as a rapid and reliable method for the authentication and quality evaluation of traditional Chinese medicine (TCM) herbs.     

GC/MS of terpenes in walnut-tree leaves after accelerated solvent extraction

Terpenes, e. g. (+)-alpha-pinene, (-)-camphene, (-)-(-pinene, myrcene, R-(+)-limonene, eucalyptol, (+/-)-linalool, (-)-bornyl acetate, (-)-trans-caryophyllene, and alpha-humulene were determined in leaves of walnut trees from the Juglandaceae family (walnut tree, royal (J. regia L.), black (J. nigra L.), and Siebold (J. sieboldiana, var. Cordiformis Lam.) using gas chromatography with mass spectrometric detection. Terpenes were repeatedly (3 cycles, 5 min each) extracted from leaves of walnut trees by accelerated (pressurized) solvent extraction (ASE) 150 bar and 120 degrees C. The efficiency of ASE extraction was superior to that of steam distillation, solvent extraction according to Soxhlet, sonication, and extraction by agitation. Differences in relative concentrations and distribution of terpenes were studied in dependence on the species of walnut tree and on different locations.     

Rapid screening of dioxin-contaminated soil by accelerated solvent extraction/purification followed by immunochemical detection

Since soils at industrial sites might be heavily contaminated with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), there is a need for large-scale soil pollution surveys and, thus, for cost-efficient, high-throughput dioxin analyses. However, trace analysis of dioxins in complex matrices requires exhaustive extraction, extensive cleanup, and very sensitive detection methods. Traditionally, this has involved the use of Soxhlet extraction and multistep column cleanup, followed by gas chromatography—high-resolution mass spectrometry (GC/HRMS), but bioanalytical techniques may allow much more rapid, cost-effective screening. The study presented here explores the possibility of replacing the conventional method with a novel approach based on simultaneous accelerated solvent extraction (ASE) and purification, followed by an enzyme-linked immunosorbent assay (ELISA). Both the traditional and the novel cleanup and detection approaches were applied to contaminated soil samples, and the results were compared. ELISA and GC/HRMS results for Soxhlet-extracted samples were linearly correlated, although the ELISA method slightly underestimated the dioxin levels. To avoid an unacceptable rate of false-negative results, the use of a safety factor is recommended. It was also noted that the relative abundance of the PCDDs/PCDFs, evaluated by principal component analysis, had an impact on the ELISA performance. To minimize this effect, the results may be corrected for differences between the ELISA cross-reactivities and the corresponding toxic equivalency factor values. Finally, the GC/HRMS and ELISA results obtained following the two sample preparation methods agreed well; and the ELISA and GC/HRMS results for ASE extracts were strongly correlated (correlation coefficient, 0.90). Hence, the ASE procedure combined with ELISA analysis appears to be an efficient approach for high-throughput screening of PCDD-/PCDF-contaminated soil samples.      

Desorption of BTEX from activated charcoal using accelerated solvent extraction: evaluation of occupational exposures

A procedure for the determination of benzene, toluene, ethylbenzene and o-xylene, m-xylene and p-xylene (BTEX) in occupational environments is proposed. These compounds are extracted from activated charcoal using accelerated solvent extraction. Operational parameters are optimized and quantitative recovery is obtained using acetonitrile as the extraction solvent and 1-mL extraction cells, a preheat time of 2 min, a temperature of 160 °C, a pressure of 1,500 psi, a static period of 5 min, a flush volume of 110%, two cycles and a purge time of 90 s. Determination of BTEX compounds is carried out by gas chromatography using a flame ionization detector. The recoveries, obtained for a confidence level of 95%, are 91 ± 4, 100 ± 3, 104 ± 2, 93 ± 4, 99 ± 2 and 99 ± 2% for benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene, respectively. The detection limits are 0.5 μg for benzene, 0.7 μg for toluene and 1.0 μg for the other compounds. The proposed procedure has been applied to real samples collected in several workplaces, like a microbiology laboratory, an analytical chemistry laboratory, a printer’s, a car repair shop and a petrol station. From the results obtained, it can be concluded that the occupational exposures determined are always acceptable because they are lower than the tenth part of the recommended exposure limits (VLA-ED and VLA-EC).     

A comparison of accelerated solvent extraction,Soxhlet extraction,and ultrasonic-assisted extraction for analysis of terpenoids and sterols in tobacco

The performance of accelerated solvent extraction in the analysis of terpenoids and sterols in tobacco samples was investigated and compared with those of Soxhlet extraction and ultrasonically assisted extraction with respect to yield, extraction time, reproducibility and solvent consumption. The results indicate that although the highest yield was achieved by Soxhlet extraction, ASE appears to be a promising alternative to classical methods since it is faster and uses less solvent, especially when applied to the investigation of large batch tobacco samples. However, Soxhlet extraction is still the preferred method for analyzing sterols since it gives a higher extraction efficiency than other methods.     

Comparison of accelerated solvent extraction with microwave-assisted extraction and Soxhlet for the extraction of chlorinated biphenyls in soil samples

The extraction and determination of chlorinated biphenyls (CBs) in soils and solid wastes is an ongoing subject of study. This is an overview article that compares the microwave-assisted extraction (MAE) and accelerated solvent extraction (ASE) techniques. The extraction of CBs by ASE has been optimised taking into account the variation of pressure, temperature and extraction time by means of experimental design and the Simplex approach. The recoveries obtained under the optimum conditions are compared and discussed with those obtained from MAE and Soxhlet extractions.     

Comparison of extraction techniques and modeling of accelerated solvent extraction for the authentication of natural vanilla flavors

Accelerated solvent extraction (ASE) of vanilla beans has been optimized using ethanol as a solvent. A theoretical model is proposed to account for this multistep extraction. This allows the determination, for the first time, of the total amount of analytes initially present in the beans and thus the calculation of recoveries using ASE or any other extraction technique. As a result, ASE and Soxhlet extractions have been determined to be efficient methods, whereas recoveries are modest for maceration techniques and depend on the solvent used. Because industrial extracts are obtained by many different procedures, including maceration in various solvents, authenticating vanilla extracts using quantitative ratios between the amounts of vanilla flavor constituents appears to be unreliable. When authentication techniques based on isotopic ratios are used, ASE is a valid sample preparation technique because it does not induce isotopic fractionation.     

Determination of acetanilide herbicides in cereal crops using accelerated solvent extraction, solid-phase extraction and gas chromatography-electron capture detector

A method was developed to determine eight acetanilide herbicides from cereal crops based on accelerated solvent extraction (ASE) and solid-phase extraction (SPE) followed by gas chromatography-electron capture detector (GC-ECD) analysis. During the ASE process, the effect of four parameters (temperature, static time, static cycles and solvent) on the extraction efficiency was considered and compared with shake-flask extraction method. After extraction with ASE, four SPE tubes (graphitic carbon black/primary secondary amine (GCB/PSA), GCB, Florisil and alumina-N) were assayed for comparison to obtain the best clean-up efficiency. The results show that GCB/PSA cartridge gave the best recoveries and cleanest chromatograms. The analytical process was validated by the analysis of spiked blank samples. Performance characteristics such as linearity, limit of detection (LOD), limit of quantitation (LOQ), precision and recovery were studied. At 0.05 mg/kg spiked level, recoveries and precision values for rice, wheat and maize were 82.3-115.8 and 1.1-13.6%, respectively. For all the herbicides, LOD and LOQ ranged from 0.8 to 1.7 μg/kg and from 2.4 to 5.3 μg/kg, respectively. The proposed analytical methodology was applied for the analysis of the targets in samples; only three herbicides, propyzamid, metolachlor and diflufenican, were detected in two samples.