固相微萃取法和液液萃取K-D浓缩法对化妆品香气的分析

分别利用固相微萃取法和液液萃取K-D浓缩法对化妆品调理水中的香气提取物进行分析比较。用这两种方法从化妆品调理水中提取、鉴定出30个化合物,从固相微萃取法提取物中鉴定出23个化合物,液液萃取K-D浓缩法提取物中鉴定出16个化合物,其中相同的化合物有9个。结果表明,两种提取方法得到的香气成分有明显差异,其香气特征成分主要集中在固相微萃取法所富集部分,因此采用固相微萃取法能够快速、高效、全面地对香气的香型进行定性分析。     

饲料中盐酸克伦特罗、沙丁胺醇高效液相色谱测定

建立了用液相色谱法同时测定饲料中违禁药物盐酸克伦特罗、沙丁胺醇含量的方法 ;样品经甲醇 -盐酸溶液提取后 ,经液 -液萃取、固相萃取小柱净化 ,用ZorbaxCN柱分离 ,二极管阵列检测器检测、外标法定量 ;盐酸克伦特罗、沙丁胺醇的定量下限(w)分别为0.10×10-6 、0.36×10-6,回收率分别大于88 %和74 % ,RSD(n=5)分别小于6.4 %和3.0%。     

固相萃取-气相色谱法测定动物组织中盐酸克伦特罗残留量

建立了固相萃取-气相色谱分析动物组织中盐酸克伦特罗残留量的方法．采用固相萃取,分离富集动物组织中的盐酸克伦特罗．肉样的加标回收率在70％～80％;最低检出限为1μg／kg．盐酸克伦特罗的硅烷化衍生产物,采用气相色谱(ECD检测器)检测,其衍生物的峰面积与样品浓度在0．005～1．0μg／mL范围内呈良好的线性关系,线性回归系数大于0．999．     

气质联用法测定饮用水嗅味物质的前处理技术

系统研究和对比了用于气相色谱-质谱联机测定饮用水嗅味物质的液-液萃取、固相萃取、固相微萃取等样品前处理技术.结果显示,采用C18为柱填料、甲醇作为洗脱剂的固相萃取法效果最优,土臭素和2-甲基异莰醇两种嗅味物质测定结果的相对标准偏差分别为1.5%和1.7%,回收率分别为98.8%～102.0%和99.5%～104.0%.     

气相色谱-电子捕获检测器法检测水中氟乐灵

建立了气相色谱仪检测水中氟乐灵的方法. 分别采用液液和固相两种萃取浓缩的方式进行样品预处理,两种方法均能满足要求. 液液萃取操作简单,节约时间. 固相萃取能实现自动化处理,节省劳力. 浓缩后使用HP-5色谱柱分离,电子捕获检测器进行测定. 试验结果表明,当水中氟乐灵的质量浓度在0.05~1.0 μg/L范围内,其工作曲线回归方程的相关系数高于0.999,方法检出限(3 S/N)为0.02 μg/L. 在两种不同浓度水平条件下对方法的回收率和精密度进行了试验,其回收率在84.0%~98.0%之间,相对标准偏差在3.0%~5.8%之间.     

土壤基质中路易氏剂的测定方法

建立了土壤基质中不同浓度的路易氏剂的测定方法,即液液萃取-气相色谱法(LEE-GC)和固相微萃取-气相色谱法(SPME-GC)。两种方法对5种土壤基质回收率均大于70％;相对标准偏差均小于10％。     

基于磁固相萃取-自动前处理分离和富集动物肝脏中的β-受体激动剂

基于磁固相萃取-自动前处理分离和富集动物肝脏中的β-受体激动剂,建立了动物肝脏中3种β-受体激动剂（沙丁胺醇、克伦特罗和莱克多巴胺）残留的液相色谱-串联质谱（LC-MS/MS）分析方法。样品溶液经提取后,采用磁性阳离子吸附剂（M-MCX）结合自动前处理装置进行净化,使用LC-MS/MS检测,同位素内标法进行定量。结果显示,M-MCX较传统混合阳离子固相萃取（MCX）柱的吸附容量高34%,而且节约了吸附材料。结合自动磁固相萃取装置,30 min内可完成8个样品的净化,方法检出限为0.01～0.1μg/kg,平均回收率为88.2%～110.5%,相对标准偏差为2.9%～10.3%。与传统柱填充式固相萃取法相比,本方法具有操作简单、快速、高效等优点,能够满足动物组织样品前处理的批量、自动化处理的需求。     

分散液液微萃取技术的研究进展

分散液液微萃取是一种基于传统液液萃取的新型样品前处理技术。该文以分散液液微萃取技术中萃取剂的筛选为出发点,综述了低密度萃取剂、辅助萃取剂、反萃取剂和离子液体等低毒性萃取剂在该技术中的应用,以及应用自制装置、溶剂去乳化、悬浮萃取剂固化,辅助萃取,反萃取和离子液体-分散液液微萃取等萃取模式;并简要评述了该技术与液液萃取、固相萃取、固相微萃取、分散固相萃取、基质固相分散萃取、超临界流体萃取、超声辅助萃取等其他样品前处理技术的联用特性。     

液液萃取-气相色谱法测定缓释尿素中吡唑类硝化抑制剂

建立了一种快速测定缓释尿素中吡唑类硝化抑制剂（DL-1）的方法-液液萃取．气相色谱法。从5种有机溶剂中选出三氯甲烷作为DL-1的萃取剂，并采用盐析的方法将革取率提高。本文采用内标法，通过SE30柱，氢火焰离子化检测器（FID）定量检测三氯甲烷萃取相中DL-1。萃取率为96．08％～98．10％，平均萃取率为97．33％；回收率为87．96％～90．54％；RSD为0．089％～1．6％，本法测定缓释尿素中的DL-1含量快速、灵敏，便于产品的质量监控。     

微晶萘固液萃取法及其在分离富集中的应用

本文对几年来国内外关于微晶萘固液萃取法在分离富集中的应用进行了综述,重点评述了微晶萘固液萃取法中的二元螯合物体系和离子缔合配合物体系,并介绍了一些其它固态萃取剂的应用。     

对氨基酚络合萃取机理的探讨

对氨基酚络合萃取机理的探讨;对氨基酚; 络合萃取; 萃取机理; 萃取反应热     

Focused microwave aqueous extraction of chlorophenols from solid matrices and their analysis by chromatographic techniques

Open-vessel focused microwave (FMW) extraction with a purely aqueous carbonate solution was used for the extraction of chlorophenols from various solid matrices. After SPE on C18-bonded silica, the analytes were determined as such by LC-UV or, as their acetyl derivatives, by GC-ECD. The FMW aqueous extraction is efficient and rapid and no organic solvents are used. PCP was detected in several solid samples, with recoveries of 101-115% (RSD, 2-4%) relative to Soxhlet extraction. Similar recoveries were obtained for the other chlorophenols for spiked samples.     

杂粮中总黄酮的提取及含量测定的实验设计

通过学生分组，采用溶剂提取法，超声提取法和微波提取法等提取方法，测定了小米、糜子、青稞、荞麦和高梁等杂粮中黄酮含量，结果表明5种杂粮中，青稞中总黄酮的含量最高。该综合实验能够锻炼大学生运用所学实验技术解决实际问题的能力，适合作为高年级本科综合实验项目开设。     

超声辅助液液萃取法提取烟用香精成分的研究

采用超声辅助液液萃取法(ULLE)提取某品牌烟用香精成分,GC-MS对其进行分析,研究了不同萃取剂、萃取时间和萃取温度对分析结果的影响,初步确定了最佳条件为:以二氯甲烷为萃取剂,饱和NaCl溶液作水相,室温下超声萃取5 min.又分别与同时蒸馏萃取法(SDE)和传统的液液萃取法(LLE)作以比较,对ULLE法和SDE法鉴定出的化学成分、重现性和定量值进行了对比.结果表明:超声辅助液液萃取具有操作简便、快速、节能、萃取效率高、重现性好等特点,适合于烟用香精成分的提取.     

中草药化学成分提取新技术

介绍五种提取新技术棗微波萃取技术、超临界二氧化碳萃取技术、超声波提取技术、半仿生提取技术和酶法的原理和特点,以及这些新技术近年来在中草药化学成分提取工艺中的研究应用现状,并展望了它们的应用前景。     

Improved extraction and clean-up of imidazolinone herbicides from soil solutions using different solid-phase sorbents

Extraction and quantification of herbicide residues from soil are important in understanding the behaviour of persistent herbicides. This research investigated extraction and clean-up methods for imidazolinone herbicides from soil and soil amended with organic material. A series of solvent mixes, pH conditions and sorbents was tested. Across three imidazolinone herbicides: imazapyr, imazethapyr and imazaquin, 0.5 M NaOH extraction gave greater than 90% recovery from soil samples; however, 0.5 M NaOH:MeOH (80:20) resulted in higher recovery for imazaquin, but not for the other two herbicides. Of the sorbents tested, the use of chromatographic mode sequencing using C₁₈ and SCX sorbents provided consistent high (>85%) recovery of all three herbicides from soil and separation of the herbicides from other soil components by high performance liquid chromatography (HPLC). These two methods will allow high recovery of these imidazolinone herbicides from soil and have the ability to detect these herbicides without interference from other soil components.     

Comparison of alternative and conventional extraction techniques for the determination of zearalenone in corn

Naturally contaminated corn samples of different origin were extracted using two conventional techniques (blending and shaking) and three alternative approaches (ultrasonic extraction, accelerated solvent extraction, and microwave-assisted extraction). Use of the same extraction mixture for all trials enabled the efficiency of the various extraction techniques to be compared. Extracts were filtered and directly analyzed by LC–ESI–MS, without further clean-up. The yield from the alternative extraction techniques showed efficiency to be higher than for conventional techniques. In particular, microwave-assisted extraction was slightly superior to other techniques.     

Supercritical fluid extraction

Supercritical fluid extraction (SFE) provides for the first time a viable option to conventional and widely used Soxhlet extraction. The ability to change the solvating power of a single supercritical fluid by changing its density is an exceedingly attractive feature. An environmentally safe alternative such as supercritical carbon dioxide to organochlorine solvents which are widely used today in many government and industrial analytical laboratories for sample preparation is desirable. SFE may also constitute a viable alternative to other popular sample preparation techniques such as liquid-liquid extraction, solid phase extraction and purge/trap. Much research, however, must be done in order to understand, optimize and apply this technology. For example, (a) automation of extraction, (b) matrix effects, (c) new fluids/modifiers/additives, (d) trapping efficiency, (e) recovery of extracted analytes, and (f) extraction kinetics are some areas which need a greater understanding. This review is concerned with many of these topics as they relate to trace organic analysis wherein SFE is the primary sample preparation technique.     

Investigation on Ochratoxin A stability using different extraction techniques

The stability of Ochratoxin A during its extraction using different extraction techniques has been evaluated. Microwave-assisted extraction and pressurised liquid extraction, in addition to two other reference methods of extraction, i.e. ultrasound-assisted and magnetic stirring-assisted extraction, were evaluated. The effect of extraction temperature using the cited techniques was checked.The results show that Ochratoxin A can be extracted using microwave-assisted extraction at temperatures up to 150 °C without degradation. Pressurised liquid extraction can be used at temperatures up to 100 °C, for extraction times of less than 30 min. Further, both ultrasound-assisted extraction and magnetic stirring extraction can be applied at temperatures up to 65 °C.High-performance liquid chromatography combined with fluorescence detection using a Chromolith RP-18e column at a flow rate of 5 mL min⁻¹ was used to quantify the Ochratoxin A. The retention time for the Ochratoxin A was 1.3 min. The limits of detection (LOD) and of quantification (LOQ) were 0.03 and 0.10 μg L⁻¹, respectively.     

Extraction of uranium(IV) and uranium(VI) by primary and tertiary-amines from sulphate solutions

In developing a method for possible low level isotopic enrichment, which uses to advantage the equilibrium isotope effect observed during U(1V)-U(VI) electron exchange reaction in sulphate solutions, details of a solvent extraction process involving high concentration of a mixture of U(IV) and U(VI) and at low acid concentrations, are described. The extraction behaviour of uranium under these conditions is discussed. During the extraction with amines, U(IV) tended to get oxidised in sulphate solutions.