超声波辅助溶剂萃取-电感耦合等离子体质谱法测定生物样品中的总汞和甲基汞

建立了超声波辅助溶剂萃取联用电感耦合等离子体质谱法（ICP-MS）测定生物样品中总汞（T-Hg）和甲基汞（MeHg）的分析方法。实验优化了萃取溶剂种类，溶剂浓度，各种辅助方法和超声波振荡时间等各种萃取条件。选择6mol·L^-1 HCl作为溶剂，超声2h，以有机溶剂萃取，再以水反萃，稀释后直接进行测量MeHg的含量。此方法可用于同时测定T-Hg和MeHg，检出限为0．01mg·mL^-1，相对标准偏差为3．44％，线性范围为1～50ng·mL^-1，加标回收率为80％～97％。在此条件下测定了5种不同类型生物标准参考物质的T-Hg和MeHg，测定值与标准值吻合。该法综合了超声波辅助萃取和溶剂微萃取以及ICP—MS的优点，操作简便快速，灵敏度高，适合于各种生物样品中痕量MeHg快速萃取分离和分析。

不同方法提取费约果叶片香气成分的比较研究

分别采用索氏抽提法、超声波辅助溶剂萃取法和顶空固相微萃取法对费约果叶片中所含香气成分进行提取,经GC-MS进行分析,结合谱库检索技术,采用峰面积归一化法进行定性和定量分析。结果表明,索氏抽提法所得香气物质中鉴定出挥发性成分20种,占总挥发性成分的70.357%,且以烷烃为主,超声波辅助溶剂萃取法所得香气物质中鉴定出挥发性成分17种,占总挥发性成分的65.222%,且以酯类为主,顶空固相微萃取法所得香气物质中鉴定出挥发性成分最多,有42种,占总挥发性成分的76.899%,且以萜烯类为主。由此可见,在费约果叶片香气成分分析中顶空固相微萃取法能得到最多的香气组分,索氏抽提法次之,超声波辅助溶剂萃取法得到的香气物质最少。

马铃薯茎叶精油成分和抗菌性研究

[目的]研究成熟马铃薯茎叶挥发性成分及其抗菌活性。[方法]用超声波辅助-溶剂萃取法提取成熟马铃薯茎叶挥发性成分,采用GC-MS联机分析化学组成,然后,以Halo法测定精油的抗菌活性。[结果]以0.520%的产率获得精油,检测出81种成分,解析鉴定了占精油71.659%的31个成分。其中,倍半萜类化合物19.629%;羧酸类化合物18.625%;饱和烃类化合物15.352%;酮类化合物6.993%;醇类4.092%;酯类3.679%和醛类2.228%。[结论]该精油对大肠杆菌、白色葡萄球菌、枯草芽孢杆菌具有很强的抗菌活性,但是,对黄色葡萄球菌、根霉的活性较低。

Evaluating the performances of accelerated-solvent extraction, microwave-assisted extraction, and ultrasonic-assisted extraction for determining PCBs, HCHs and DDTs in sediments

Three extraction techniques have been recently used for the quantitative extraction of semi-volatile organic pollutants in sediments, i.e. accelerated solvent extraction （ASE）, microwave assisted extraction （MAE） and ultrasonic assisted extraction （UAE）. However, their extraction efficiencies have rarely been quantitatively compared using rigorous mathematical methods. In this paper, one-way analysis of variance （ANOVA） was employed to evaluate the performance of ASE, MAE and UAE in the overall extraction of PCBs, DDTs and HCHs by analysis of their recoveries from the Standard Reference Material IAEA-417, a sediment sample certified by many international laboratories. Conclusions were drawn at a significance level of P〈 0.05. No significant differences were found among the mean values for method recoveries using ASE, MAE and UAE. The mean values for real recoveries using ASE and MAE were nearly identical, but the real recovery using UAE was much lower. The concentrations of all PCBs, DDTs and HCHs except for CB52 and o,p＇-DDT using UAE were the lowest. Comparing the results obtained using ASE with MAE, the concentrations of CB28, CB52, CB138, ct-HCH, [3-HCH, p,p＇-DDE and p,p＇-DDD were nearly identical, while the concentrations of other compounds were significantly different. Based on the low recoveries, it was concluded that UAE is a relatively inefficient extraction method, while ASE and MAE are equivalent methods. Taking into consideration the relative standard deviation （RSD） values, solvent volume, extraction time, and purchasing costs of the apparatus, MAE was considered superior to ASE for extraction of PCBs, DDTs and HCHs.

Analysis of volatile components in saffron from Tibet and Henan by ultrasonic-assisted solvent extraction and GC-MS

To determine the chemical constituents of volatile components in saffron from the Tibet Autonomous Region and the Henan Province of China and to compare the chemical composition difference in the saffron,the total volatile components were extracted by ultrasonic-assisted solvent extraction（USE）,using five different solvents：diethyl ether,ethanol,ethyl acetate, dichloromethane and acetone,analyzed using gas chromatography-mass spectrometry（GC-MS）and compared to the standard MS data,and their relative contents were calculated by area normalization.The results showed both that USE was an efficient and rapid method for the extraction of the volatile components from saffron and that the components extracted from the same sample using different solvents were different.Comparison of the experimental results of saffron from the Tibet Autonomous Region and the Henan Province of China showed that their volatile components were different in their chemical composition and in their relative percentages.USE/GC-MS is a simple,rapid,and effective method for the analysis of volatile oil components in saffron.