超声雾化提取法测定3种香料中的挥发性成分

用超声雾化提取法提取,气相色谱法检测八角茴香和小茴香中反式茴香醚以及花椒中柠檬烯的含量.最佳提取条件为100 mg样品加入15 mL正己烷提取液,在35 W的超声功率下提取5 min(八角茴香和小茴香)或30 min(花椒).测定反式茴香醚的回收率在90.9%～100.7%之间,柠檬烯的回收率在90.0%～98 6%之间.将所建立的超声雾化提取法与常用的超声辅助提取法和索氏提取法进行了比较,证明所建立的方法具有提取时间短、效率高、设备简单且没有噪音污染等优点.     

Ultrasonic nebulization extraction coupled with headspace hollow fiber microextraction of pesticides from root of Panax ginseng C.A. Mey

The ultrasonic nebulization extraction coupled with headspace hollow fiber microextraction (UNE-HS-HFME) was applied for the extraction of pesticides from root of Panax ginseng C.A. Mey. Experimental parameters, which affect the performances of ultrasonic nebulization extraction coupled with headspace hollow fiber microextraction, such as the kind of acceptor solvent in the pore of the fiber wall, the sample amount, extraction time, salt concentration in extraction solvent, pH of the acceptor solution, the elution time, and times were studied and optimized. The analytes were determined by high-performance liquid chromatography. The detection limits for simeton, monolinuron, chlortoluron, karmex, and prebane are 20.9, 18.4, 18.2, 12.4, and 22.2 μg/kg, respectively. Besides volatile and semi-volatile compounds, the non-volatile compounds also can be determined by the proposed method. The extraction and enrichment process can be performed simultaneously.     

Ultrasonic nebulization extraction-heating gas flow transfer-headspace single drop microextraction of essential oil from pericarp of Zanthoxylum bungeanum Maxim

The ultrasonic nebulization extraction-heating gas flow transfer coupled with headspace single drop microextraction (UNE-HGFT-HS-SDME) was developed for the extraction of essential oil from Zanthoxylum bungeanum Maxim. The gas chromatography-mass spectrometry was applied to the determination of the constituents in the essential oil. The contents of the constituents from essential oil obtained by the proposed method were found to be more similar to those obtained by hydro-distillation (HD) than those obtained by ultrasonic nebulization extraction coupled with headspace single drop microextraction (UNE-HS-SDME). The heating gas flow was firstly used in the analysis of the essential oil to transfer the analytes from the headspace to the solvent microdrop. The relative standard deviations for determining the five major constituents were in the range from 1.5 to 6.7%. The proposed method is a fast, sensitive, low cost and small sample consumption method for the determination of the volatile and semivolatile constituents in the plant materials.     

超临界流体萃取-GC-MS分析西黄丸中挥发性成分

建立西黄丸中挥发油成分乙酸辛酯的含量测定方法,为西黄丸的质控标准提供依据。方法:超临界CO2萃取西黄丸中挥发油成分,采用气相色谱法测定乙酸辛酯含量;研究压力、温度、时间和粒度因素对挥发油得率与乙酸辛酯含量的影响,并进行了化学计量学分析。采用GC-MS分析了适宜条件的挥发油的成分。综合考虑挥发油得率和乙酸辛酯含量双指标,确定的西黄丸挥发油萃取条件为:粉碎粒度为80目,萃取压力为25 MPa,温度为40℃,时间为2 h。在此条件下,挥发油得率达到7.76%,乙酸辛酯含量达到0.72 mg·g^-1。通过指纹图谱、主成分分析(PCA)、正交偏最小二乘判别分析(OPLS-DA)化学计量学分析可知,不同萃取条件对所提取的挥发油物质组分及其含量没有显著性差异。GC-MS鉴定出的主要成分有(1S-endo)-2-甲基-3-亚甲基-2-(4-甲基-3--3-戊烯基)-二环[2.2.1庚烷、10α-羟基日本刺参萜、(±)-麝香酮、4-亚甲基-2,8,8-三甲基-2-乙烯基-双环[5.2.0]壬烷和2-甲基-4-(2,6,6-三甲基-1-环己烯-1-基)丁醛。结论:西黄丸挥发油成分适宜萃取条件,及建立的乙酸辛酯含量测定方法准确、可靠,为有效控制西黄丸质量,完善其质量标准及进一步的药效成分研究提供了科学依据。     

Ultrasonic nebulization extraction coupled with headspace single-drop microextraction of volatile and semivolatile compounds from the seed of Cuminum cyminum L

Ultrasonic nebulization extraction (UNE) coupled with headspace single-drop microextraction (HS-SDME) was developed. In the UNE process, the analytes were transferred from the aqueous phase to the gas phase. Then the analytes were transferred from the gas phase to the solvent phase by the carrier gas and extracted and enriched with suspended microdrop solvent. Finally, the microdrop solvent injected into GC-MS system. The parameters affecting extraction performance, such as type of suspended solvent, microdrop volume, flow rate of carrier gas, temperature of extraction vessel and extraction time were investigated and optimized. The proposed method can be applied for the extraction and enrichment of the volatile and semivolatile compounds simultaneously. The extraction efficiency of the proposed method was compared with that of ultrasonic extraction (UE) and UE-HS-SDME. Compared with UE-HS-SDME, the contents of constituents in the extract obtained by the proposed method were closer to those obtained by hydrodistillation (HD), which is a standard extraction method.     

Inductively coupled plasma optical emission spectrometric determination of trace elements in sediments after sequential selective extraction: effects of reagents and major elements on the analytical signal

The interfering effects due to the reagents and matrix elements associated with a four step sequential extraction procedure on ICPOES determination of trace elements were investigated in a systematic way. The emission lines were selected in order to include the most interesting elements for environmental studies (Zn, Pb, Ni, Cr, V and Cu) and the concentrations ranged according with the values occurring in the real samples. In order to distinguish between chemical and physical interfering effects, the Mg 280.270–Mg 285.213 line intensity ratio was measured, in each condition. Both pneumatic and ultrasonic nebulization were considered for comparison. It was found that both the elements which constitute the sample and the reagents which are added during the sample preparation steps significantly influence the emission intensity of all the analytes, depending on the analytical concentration and the nebulization system. Generally, the signal variations were higher with ultrasonic nebulization. Concerning the interference mechanism, it was found that the effect of the major elements (Na, K, Mg, Ca, Al and Fe) is essentially related to a change of the aerosol generation and transport processes. Differently, acetic acid, ammonium acetate and hydroxylamine hydrochloride significantly improved the plasma excitation conditions, depending on their concentration. A change of the sample introduction efficiency due to the presence of these reagents was also evident. On the contrary, the effect of hydrochloric and nitric acid emerged to be related only to the processes occurring in the sample introduction system.     

FI溶剂萃取与ICP-AES联机的研究水样中微量铜的测定

本文建立了用FI-溶剂萃取-ICP-AES测定水样中微量铜的分析方法。选择了ICP-AES、超声雾化发生器及FIA的最佳工作条件。研究了溶液pH对用打萨腙-四氯化碳体系萃取铜的影响;有机相流速与水相流速之比例;萃取盘管长度等因素对萃取过程及等离子体放电的影响。分析了自来水样品及美国标准局标准水样中铜含量。统计了分析方法的精密度、检出限与实验条件下的富集倍数。     

Headspace solvent microextraction: a very rapid method for identification of volatile components of Iranian Pimpinella anisum seed

At the present study, a new and rapid headspace solvent microextraction (HSME), for the extraction and pre-concentration of the volatile components of plant sample into a microdrop was applied. The extraction occurred by suspending a microliter drop of the solvent from the tip of a microsyringe to the headspace of a ripen and powdered dry fruit sample (Iranian Pimpinella anisum seed) in a sealed vial for a preset extraction time, then the microdrop was retracted back into the microsyringe and injected directly into a GC injection port. The chemical composition of the HSME extracts were confirmed according to their retention indexes and mass spectra (EI, 70 eV); and quantitative analysis was performed by GC-FID.Parameters such as the nature of the extracting solvent, particle size of the sample, temperatures of the microdrop and sample, volume of sample and the extraction time were studied and optimized, and the method's performance was evaluated. The optimized conditions were: sample particle size, 1 mm; sample volume, 5 ml (in a 15 ml vial); sample temperature, 60 °C; microsyringe needle temperature, 0 °C; and extraction time, 10 min. Finally, accordingly, the percentage of trans-anethole (the major compound of P. anisum) and the relative standard deviation for extraction and determination of trans-anethole (seven-replicated analysis) were determined to be 90% and 3.9%, respectively.     

气相色谱-质谱指纹图谱法研究普洱茶醇溶物挥发性成分

以普洱茶7542为参考样本, 乙醇为溶剂, 超声提取制备普洱茶醇溶物, 建立了普洱茶7542醇溶物气相色谱-质谱(GC-MS)指纹图谱, 同时对其指纹图谱进行相似度计算和主成分分析.试验结果表明, 普洱茶醇溶物的最佳提取方法:采用50 mL 95%乙醇超声提取30 min, 顶空进样最佳条件为振荡箱温度110℃, 振荡时间20 min.通过对9个不同年限、不同批次的普洱茶7542系列样品醇溶物挥发性成分GC-MS指纹图谱进行相似度分析, 测定样品醇溶物挥发性成分图谱与对照图谱之间的相似度在0.706~0.906之间, 说明不同年限、不同批次的9个普洱茶7542醇溶物挥发性成分和参照样本相比发生了改变, 但变化较小, 但其共有成分峰面积百分含量存在差异.通过对9个不同年限、不同批次普洱茶7542醇溶物挥发性成分共有成分进行主成分分析, 提取了2个成分, 即2-羟甲基-2-甲基-吡咯烷-1-甲醛和N-丁基苯磺酰胺, 其特征值大于1, 累计方差贡献率达90.2%, 能较好的代表 9个不同年限、不同批次普洱茶7542的全部信息, 可以用主成分分析来反映样品的全部信息.因此可通过测定9个不同年限、不同批次普洱茶7542醇溶物中2-羟甲基-2-甲基-吡咯烷-1-甲醛和N-丁基苯磺酰胺的含量差异评价普洱茶7542的质量.     

超声雾化进样法MPT－AFS的研究

本文对超声雾化进样微波等离子体炬（ＭＰＴ）原子荧光光谱法（ＡＦＳ）的分析性能进行了研究，在实验中详细地考察了各种实验条件和仪器参数对分析性能的影响，并利用此方法对Ｚｎ、Ｃｄ等元素进行了分析测定研究，并对这种等离子体的荧光发射区域作了探讨。     

Determination of Lignans in Schisandra sphenanthera and Schisandra chinensis Using Ionic Liquid-based Ultrasonic-assisted Extraction and High-performance Liquid Chromatography

A green, rapid and precise sample pretreatment technique, IL-based UAE(ionic liquid-based ultrasonic-assisted extraction), was coupled with high-performance liquid chromatographic separation to identify the main effective components in Schisandra sphenanthera(S. sphenanthera) and Schisandra chinensis(S. chinensis) including schisantherin A, schisandrin A, and deoxyschizandrin. Four different types of ionic liquids have been investigated, finally[C₆MIM] [BF₄] was used as the extraction solvent. A powder form of S. sphenanthera and S. chinensis was mixed with the[C₆MIM] [BF₄] to produce a suspension. This suspension was ultrasonically extracted in a water bath at room temperature. Several of the process parameters were optimized, including the type of ionic liquid used and its volume, the sample amount, the size of the sample particle, the extraction time, etc. HPLC calibration curves were established for all the analytes and proved to be linear(r>0.9999). The lowest detection level for schisandrin A was 0.12 μg/mL, for schisantherin A was 0.08 μg/mL, and for deoxyschizandrin was 0.10 μg/mL. The recoveries of the target compounds were from 74.19% to 109.33%. The standard deviations for detection were generally no more than 6.31%. In contrast to conventional extraction methods, the IL-based UAE did not involve volatile organic volatile solvents, and the analysis time, required sample and solvent volumes were also lower than those of the conventional techniques.     

Development of gas chromatography-mass spectrometry following microwave distillation and simultaneous headspace single-drop microextraction for fast determination of volatile fraction in Chinese herb

In this work, for the first time, microwave distillation (MD) coupled with simultaneous headspace single-drop microextraction (HS-SDME) was developed for the determination of the volatile components in the Chinese herb, Artemisia capillaris Thunb. The volatile components were rapidly isolated by MD, and simultaneously extracted and concentrated by using a dodecane microdrop. The volatile oil extracted in the microdrop solvent was analyzed by gas chromatography-mass spectrometry (GC-MS). The experimental parameters of solvent selection, microdrop volume, microwave power, irradiation time and sample amount were investigated, and the method precision was also studied. The optimal parameters were extraction solvent of dodecane, solvent volume of 2.0 microL, microwave power of 400 W, irradiation time of 4 min, and sample amount of 2.0 g. Thirty-five volatile compounds present in Artemisia capillaris Thunb. were identified by using the proposed method, which were identical with those obtained by the conventional steam distillation method. The experimental results showed that MD-HS-SDME is a simple, rapid, reliable, and solvent-free technique for the determination of volatile compounds in Chinese herbs.     

Spectroscopic and analytical characteristics of an inductively coupled argon plasma combined with hydride generation with or without simultaneous introduction of the sample aerosol for optical emission spectrometry

A radially viewed inductively coupled argon plasma was used for optical emission spectrometry of volatile species formed by reaction with NaBH₄ (hydride generation). The volatile hydrides were either introduced into the plasma alone or at the same time as a sample aerosol generated by pneumatic nebulization with a commercially available Concomitant Metals Analyzer. The effects of the forward power, the presence of pre-reducing agents [(NH₂)₂SC, KI, KBr and hot HCl], the occurrence of easily ionized elements (Ca, K, Mg and Na) in the analyte solutions on the excitation temperature (as measured via Ar atomic lines) and the electron number density were investigated for both of the sample introduction modes applied. The detection limits and the signal-to-background intensity ratios for As, Bi, Sb, Se and Sn lines were also evalutated and were observed to deteriorate with increasing power. When simultaneous hydride generation and pneumatic nebulization was employed under optimized experimental conditions, detection limits of 3.5, 2.9, 4.3, 1.5 and 2.1 μg L⁻¹ for As, Bi, Sb, Se and Sn, respectively, were obtained, and the intensities of the analytical lines for elements that do not form volatile hydrides were found to be 40% (Cd), 30% (Ni), 20% (Co, Cr, Fe, Mn and Zn) and 10% (Cu, Mg, V) greater than those obtained when only pneumatic nebulization was used.     

等离子体原子光谱分析中溶液样品雾化进样方法的新进展

对近年来等离子体原子光谱分析中溶液样品引入方法的新进展作了综述，其中包括气动雾化法、超声雾化法、热雾化法、悬浆雾化法、高水压雾化法及电喷雾法等。文中还根据本课题组多年来的研究经验对每种方法的优缺点及其应用作了简要的介绍和评论。     

黄花菜中黄酮的超声波提取、纯化及鉴定

用正交实验法对黄花菜中黄酮的超声波提取工艺中的超声功率、样品细度、固液比例、提取时间4个因素进行了研究,优选出简便可靠的黄酮提取工艺。其最佳提取工艺条件是:黄花菜过60目筛后,超声波功率为高档,固液比为1:10,提取为20 min。通过红外光谱、紫外光谱、色谱分析可以确定黄花菜中的黄酮是黄酮醇类黄酮。     

Preparation of Small Particle Sized ZnAl-Hydrotalcite-Like Compounds by Ultrasonic Crystallization

Ultrasonic technology has been intensively studied recently due to its special features. In this paper, an ultrasonic crystallization method was introduced for the preparation of ZnAl-Hydrotalcite-Like compounds (ZnAl-HTLcs). Samples with high crystallinity, small particle size and narrow particle size distribution were obtained and fully characterized using conventional techniques of XRD, FT-IR and TGDTA. The results prove that both ultrasonic frequency and ultrasonic power have effects on the sizes of the product particles. By varying the ultrasonic power from 250 W to 88 W, with the ultrasonic frequency fixed at 59 kHz, the median particle size of the samples increased from 0.37 μm to 0.82 μm. By altering the hydrothermal treatment time from 1 h to 5 h at 110℃, the median particle size of ZnAl-HTLcs synthesized via ultrasonic crystallization increased from 0.88 μm to 1.11 μm.     

Direct ultrasonic agitation for rapid extraction of organic matter from airborne particulate

Direct ultrasonic extraction (DUE) is proposed as simple and rapid sample pretreatment method. This new approach is applied to the extraction of particulate organic matter (POM) from airborne particulate by using dichloromethane (DCM) or DCM/methanol (90/10, v/v) as extractant. The analytical determination was carried out by weighing the extractable POM on an electrobalance. Total recovery for POM could be obtained when the sample was extracted three times with 25–50 mL extractant each for about 5 min at 50 W ultrasonic power. In comparison with conventional Soxhlet extraction, less extraction time (total 15 min only) and solvent consumption(100 mL) were required by DUE. The efficiency of the DUE was similar or even higher than the routine Soxhlet method. Additionally, the new extractor is very simple and easy to use and can accelerate the extraction procedures of organic components from various solid samples.     

Direct ultrasonic agitation for rapid extraction of organic matter from airborne particulate

Direct ultrasonic extraction (DUE) is proposed as simple and rapid sample pretreatment method. This new approach is applied to the extraction of particulate organic matter (POM) from airborne particulate by using dichloromethane (DCM) or DCM/methanol (90/10, v/v) as extractant. The analytical determination was carried out by weighing the extractable POM on an electrobalance. Total recovery for POM could be obtained when the sample was extracted three times with 25-50 mL extractant each for about 5 min at 50 W ultrasonic power. In comparison with conventional Soxhlet extraction, less extraction time (total 15 min only) and solvent consumption (100 mL) were required by DUE. The efficiency of the DUE was similar or even higher than the routine Soxhlet method. Additionally, the new extractor is very simple and easy to use and can accelerate the extraction procedures of organic components from various solid samples.     

Ultrasonic nebulization extraction coupled with headspace single drop microextraction and gas chromatography-mass spectrometry for analysis of the essential oil in Cuminum cyminum L.

A novel method for analysis of essential oil in Cuminum cyminum L. using simultaneous ultrasonic nebulization extraction and headspace single drop microextraction (UNE-HS-SDME) followed by gas chromatography-mass spectrometry was developed. Experimental parameters, including the kind of suspended solvent, microdrop volume, sample amount, extraction time, enrichment time and salt concentration were examined and optimized. Compared with hydrodistillation (HD), UNE-HS-SDME provides the advantages of a small amount of sample (50 mg), time-saving (20 min), simplicity, cheapness and low toxicity. In addition, UNE-HS-SDME also provided higher enrichment efficiency and sensitivity compared with stirring extraction (SE)-HS-SDME, ultrasonic assistant extraction (UAE) and UNE. Some constituents in the essential oil, were identified and the detection limits for β-pinene, p-cymene and γ-terpinene range from 6.67 pL L⁻¹ to 14.8 pL L⁻¹. The results indicated that the UNE-HS-SDME is simple and highly efficient extraction and enrichment technique.     

Analysis of Volatile Compounds in the Pericarp of Zanthoxylum bungeanum Maxim. by Ultrasonic Nebulization Extraction Coupled with Headspace Single-Drop Microextraction and GC–MS

Ultrasonic nebulization extraction (UNE) combined with headspace single-drop microextraction (HS-SDME) and gas chromatography–mass spectrometry (GC–MS) have been used for rapid analysis of volatile components of the pericarp of Zanthoxylum bungeanum Maxim. Effective extraction was achieved by suspending 2 μL n-heptadecane from the tip of a microsyringe, extracting for 15 min, and enriching for 25 min. The method combines the advantages of UNE and HS-SDME. Thirty-four compounds were identified in the pericarp of Zanthoxylum bungeanum Maxim. Compared with stirring extraction (SE)-HS-SDME and UNE, UNE-HS-SDME was resulted in higher extraction yield, enrichment efficiency, and sensitivity. The results indicate that UNE-HS-SDME is a feasible alternative method for analysis of essential oils from spices.