Solid-phase microextraction of endogenous metabolites from intact tissue validated using a Biocrates standard reference method kit

Improved analytical methods for the metabolomic profiling of tissue samples are constantly needed.Currently,conventional sample preparation methods often involve tissue biopsy and/or homogenization,which disrupts the endogenous metabolome.In this study,solid-phase microextraction(SPME)fibers were used to monitor changes in endogenous compounds in homogenized and intact ovine lung tissue.Following SPME,a Biocrates AbsoluteIDQ assay was applied to make a downstream targeted metabolomics analysis and confirm the advantages of in vivo SPME metabolomics.The AbsoluteIDQ kit enabled the targeted analysis of over 100 metabolites via solid-liquid extraction and SPME.Statistical analysis revealed significant differences between conventional liquid extractions from homogenized tissue and SPME results for both homogenized and intact tissue samples.In addition,principal component analysis revealed separated clustering among all the three sample groups,indicating changes in the metabolome due to tissue homogenization and the chosen sample preparation method.Furthermore,clear differences in free metabolites were observed when extractions were performed on the intact and homogenized tissue using identical SPME procedures.Specifically,a direct comparison showed that 47 statistically distinct metabolites were detected between the homogenized and intact lung tissue samples(P<0.05)using mixed-mode SPME fibers.These changes were probably due to the disruptive homogenization of the tissue.This study's findings highlight both the importance of sample preparation in tissue-based metabolomics studies and SPME's unique ability to perform minimally invasive extractions without tissue biopsy or homogenization while providing broad metabolite coverage.

Combination of hollow fiber-based liquid-phase microextraction with sweeping techniques in micellar electrokinetic chromatography for the determination of Strychnos alkaloids in human urine

A new method for the enrichment of Strychnos alkaloids in biological samples via liquid-phase microextxaodon （LPME） based on porous polypropylene hollow fibers in combination with on-line sweeping in micellar electrokinodc chromatography was developed. The calibration curve was linear over the range of 20-200 ng mL^-1 for both strychnine and brucine in human urine sample. The detection limits （S/N = 3：1） for strychnine and brucine were 1 ng mL^-1 and 2 ng mL^-1, respectively. The LPME-sweeping method has been successfully applied to the analysis of strychnine and brucine in real urine samples.

Trace Determination of Tamoxifen in Biological Fluids Using Hollow Fiber Liquid-Phase Microextraction Followed by High-Performance Liquid Chromatography-Ultraviolet Detection

The applicability of hollow fiber liquid-phase microextraction (HF-LPME) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was evaluated for the extraction and determination of tamoxifen (TAM) in biological fluids including human urine and plasma. The drug was extracted from a 15 mL aqueous sample (source phase;SP) into an organic phase impregnated in the pores of the hollow fiber (membrane phase;MP) followed by the back-extraction into a second aqueous solution (receiving phase;RP) located in the lumen of the hollow fiber. The effects of several factors such as the nature of organic solvent, compositions of SP and RP solutions, extraction time, ionic strength and stirring rate on the extraction efficiency were examined and optimized. An enrichment factor of 360 along with substantial sample clean up was obtained under the optimized conditions. The calibration curve showed linearity in the range of 1 - 500 ng?mL–1 and the limit of detection was found to be 0.5 ng?mL–1 in aqueous medium. A reasonable relative recovery (≥89%) and satisfactory intra-assay (3.7% - 4.2%, n = 3) and inter-assay (7.5% - 7.8%, n = 3) precision illustrated good performance of the analytical procedure in spiked human urine and plasma samples.

Hollow fiber-based liquid phase microextraction followed by analytical instrumental techniques for quantitative analysis of heavy metal ions and pharmaceuticals

Hollow-fiber liquid-phase microextraction(HF-LPME)and electromembrane extraction(EME)are miniaturized extraction techniques,and have been coupled with various analytical instruments for trace analysis of heavy metals,drugs and other organic compounds,in recent years.HF-LPME and EME provide high selectivity,efficient sample cleanup and enrichment,and reduce the consumption of organic sol-vents to a few micro-liters per sample.HF-LPME and EME are compatible with different analytical in-struments for chromatography,electrophoresis,atomic spectroscopy,mass spectrometry,and electrochemical detection.HF-LPME and EME have gained significant popularity during the recent years.This review focuses on hollow fiber based techniques(especially HF-LPME and EME)of heavy metals and pharmaceuticals(published 2017 to May 2019),and their combinations with atomic spectroscopy,UV-VIS spectrophotometry,high performance liquid chromatography,gas chromatography,capillary elec-trophoresis,and voltammetry.

Dynamic microwave-assisted extraction combined with liquid phase microextraction based on the solidification of a floating drop for the analysis of organochlorine pesticides in grains followed by GC

A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.

Comparison of Headspace Solid-Phase Microextraction with Simultaneous Steam Distillation Extraction for the Analysis of the Volatile Constituents in Chinese Apricot

Volatile constituents in fully mature fruits of apricot （Prunus armeniaca L.） cultivar Xinshiji were extracted using headspace solid-phase microextraction （HS-SPME） and simultaneous steam distillation extraction （SSDE） and then analyzed using capillary gas chromatography and gas chromatography-mass spectrometry. A total of 70 components were identified by HSSPME, including 20 esters, 19 hydrocarbons, 5 alcohols, 5 ketones, 4 acids, 4 lactones, 3 aldehydes, and 10 miscellaneous components, with the esters being the dominant constituent. On the basis of the odor unit values, it is believed that the following compounds probably contributed to the fresh apricot odor： hexyl acetate, β-ionone, butyl acetate, （E）-2-hexenal, linalool, limonene, γ-decalactone, and hexanal. A total of 49 components were also detected by SSDE, including 13 hydrocarbons, 9 alcohols, 7 aldehydes, 9 esters, 4 ketones, 4 lactones, 2 acids, and 1 miscellaneous component, of which the monoterpene alcohols were the dominant constituents. It could be judged from the odor unit values that the following compounds were the major contributors to boiled apricot aroma： β-ionone, linalool, hexyl acetate, γ-dodecalactone, γ- decalactone, （E）-2-hexenal, hexanal, γ-octalactone, phenylacetaldehyde, butyl acetate, limonene, α-terpineol, and δ-decalactone. The results show that HS-SPME is a simple, rapid, and solvent-free method, which is an alternative to the classical SSDE.

Gas-liquid-liquid extraction in a novel rotating microchannel extractor

In this work,a novel rotating microchannel extractor(RME)is designed and further used for the extraction of chromium(Ⅲ)from water.Unexpectedly,the micro-extraction had the same effect as carrying out 2.9-stage cross-flow extractions.Various factors,including the gas intake methods,gas intake quantity(Qg),distance between inner rotor and outer wall(D),rotational inner rotor speed(R)and volumetric flow rate(Qa,Qo),were selected to investigate their effect on the extraction efficiency(η)thoroughly.The relation map ofηwith Weaand We(o-g)for RME provides a comprehension for the gas–liquid–liquid extraction process in this RME system.

Combination of ionic liquid dispersive liquid-phase microextraction and high performance liquid chromatography for the determination of triazine herbicides in water samples

A temperature-controlled ionic liquid dispersive liquid-phase microextraction in combination with high performance liquid chromatography was developed for the enrichment and determination of triazine herbicides such as cyanazine,simazine,and atrazine in water samples.1-Octyl-3-methylimidazolium hexafluorophosphate（[C8MIM][PF6]） was selected as the extraction solvent.Several experimental parameters were optimized.Under the optimal conditions,the linear range for cyanazine was in the concentration range of 0.5–80 mg/L and the linear range for simazine and atrazine was in the range of1.0–100 mg/L.The limit of detection（LOD,S/N = 3） was in the ranges of 0.05–0.06 mg/L,and the intra day and inter day precision（RSDs,n = 6） was in the ranges of 3.2%–6.6% and 4.8%–8.9%,respectively.Four real water samples were analyzed with the developed method,and the experimental results showed that the spiked recoveries were satisfactory.All these exhibited that the developed method was a valuable tool for monitoring such pollutants.

Electromembrane extraction–Recent trends and where to go

Electromembrane extraction(EME) is an analytical microextraction technique, where charged analytes(such as drug substances) are extracted from an aqueous sample(such as a biological fluid), through a supported liquid membrane(SLM) comprising a water immiscible organic solvent, and into an aqueous acceptor solution. The driving force for the extraction is an electrical potential(dc) applied across the SLM. In this paper, EME is reviewed. First, the principle for EME is explained with focus on extraction of cationic and anionic analytes, and typical performance data are presented. Second, papers published in 2016 are reviewed and discussed with focus on(a) new SLMs,(b) new support materials for the SLM,(c) new sample additives improving extraction,(d) new technical configurations,(e) improved theoretical understanding, and(f) pharmaceutical new applications. Finally, important future research objectives and directions are defined for further development of EME, with the aim of establishing EME in the toolbox of future analytical laboratories.

不同萃取方法下绿萼梅花蕾挥发性成分的差异研究

2023年3月13日,从浙江省长兴县东方梅园有限公司梅花基地采集绿萼梅花蕾,采用顶空-固相微萃取、水蒸气蒸馏、超临界二氧化碳3种萃取方法,结合气相色谱-质谱联用仪(GC-MS)分析绿萼梅Prunus mume f.viridicalyx花蕾中的挥发性成分,以明确其花蕾中挥发性成分组成、含量及不同萃取方式对挥发性成分萃取效果的影响。结果表明,三种萃取方法获得的绿萼梅花提取物中共鉴定出醛、醇、酮、烯等9类57种化合物,主要挥发性成分是苯甲醛、壬醛、金合欢醇、苯甲酸、α-香树脂醇、D-柠檬烯,其中苯甲醛含量最高。绿萼梅花顶空-固相微萃取物中共鉴定出21种化合物,以醛、醇和酯类化合物为主;水蒸气蒸馏物中共鉴定出30种化合物,以酯、烯、酮等水难溶化合物为主;而超临界二氧化碳提取物中共鉴定出30种化合物,以长链烷、酯类化合物为主。三种提取方法中超临界二氧化碳萃取物中蜡质含量较高,顶空-固相微萃取和水蒸气蒸馏法结合更适合作为植物芳香类挥发物的检测手段。

电膜萃取前处理技术的应用研究进展

电膜萃取(EME)作为一种新型的、方便高效的样品前处理技术,可以应用于食品检测、药物分析、环境监测、生物分析等领域的复杂检材前处理中。通过优化溶液酸度、萃取电压、萃取时间、支撑液膜的组成等,实现短时间内从各种基质样品中萃取目标物。介绍了EME的传质原理和模式,分析了中空纤维、平板膜、芯片、凝胶EME模式的特点。列举了电膜萃取食品中有害物质的应用研究,以及复杂基质中组织胺、麻醉药品和精神药品、医源性药物、多肽和金属离子快速提取中的实际应用,未来可在膜材料及联用技术方面进行深入研究(引用文献38篇)。

10种特级酱油香气差异分析

研究不同酱油的香气差异有利于从原料和酿造工艺角度加强其风味品质控制和质量提升。采用固相微萃取和固相萃取与气相色谱-质谱联用法对10种特级酱油(CB、HT1、HT2、LH、LJJ1、LJJ2、QH、XH1、XH2、WZ)中的挥发性香气成分进行定性和定量分析,结合感官评价、香气活性值(Odor activity value,OAV)和偏最小二乘回归分析(Partial least squares regression,PLSR)进一步分析不同特级酱油的香气差异及其贡献。结果表明,在10种特级酱油中共检测到86种香气化合物,其中44种化合物在10种酱油中共有。共30种香气物质的OAV≥1,其中5-乙基-4-羟基-2-甲基-3(2H)-呋喃酮的OAV(373~4698)值最高,其次为4-甲氧基-2,5-二甲基-3(2H)-呋喃酮(0~1473)。WZ酱油的烟熏香较强,其酚类和酮类化合物种类最多。CB酱油整体香气强度最小,乙醇(25.775μg/L)远低于其余9种酱油;但其吡嗪类物质含量最高(182.796μg/L),其中2,6-二甲基吡嗪含量为66.256μg/L。XH1酱油的酱香与醇香较为强烈,其乙醇(147.257μg/L)含量最高,酚类物含量同样较高,其中4-乙基-2-甲氧基苯酚为18240.479μg/L。XH2酱油的麦芽香强烈。LH酱油的异丁醇(51.223μg/L)和2,3-丁二醇(57921.798μg/L)含量在所检测样品中均为最高。HT1酱油中1-辛烯-3-醇(61.219μg/L)含量最高。综合OAV与PLSR分析,乙酸乙酯、3-羟基-2-丁酮、2,3-丁二醇、3-乙基-2,5-二甲基吡嗪、4-甲氧基-2,5-二甲基-3(2H)-呋喃酮、4-乙基愈创木酚和4-乙基苯酚为10种特级酱油香气差异的关键成分。

六方氮化硼应用于样品前处理的研究进展

近几年,六方氮化硼由于孔隙率高、比表面积大、机械强度高、化学稳定性好、亲水性好、生物相容性好等优点,作为前处理材料获得了广泛关注,已被用于生物化学、食品安全、环境污染等领域的样品前处理,是一种理想的吸附剂。目前已开发了多种基于六方氮化硼材料作为吸附剂的样品前处理技术,包括固相萃取、分散固相萃取、固相微萃取、磁性固相萃取、管内固相微萃取、分散固相微萃取等,可实现多氯联苯、罗丹明B、黄酮类化合物、多环芳烃等分析物的萃取富集。综述了六方氮化硼材料在样品前处理领域的应用进展,并对今后的发展方向进行了展望。

基于SPME-GC-MS的杏子提取物挥发性成分分析及其应用

采用固相微萃取结合GC-MS技术对杏子提取物的挥发性成分进行分析鉴定。结果表明,从杏子提取物中共鉴定出50种挥发性成分,其主要成分为香茅醛(17.28%)、柠檬烯(11.04%)、丁香酚(7.64%)、香茅醇(7.25%)、香芹酮(6.28%)等物质构成了杏子提取物的主体香韵,能够增加卷烟果香、甜香、膏香、清香香韵,降低卷烟的辛辣感和刺激性,提升烟气品质,改善余味,提高卷烟吸食品质。

顶空固相微萃取-气相色谱质谱法测定水体中的苯甲醚

建立了顶空固相微萃取-气相色谱质谱法定性定量检测水中苯甲醚的分析方法。对影响检测结果的因素如萃取头的选择、萃取时间等进行了优化。经过条件优化,方法在1~1000μg/L范围内线性良好,线性相关系数>0.999,实际水样加标质量浓度分别为10,60,300μg/L时,加标回收率为85%~120%,相对标准偏差(RSD)为3.95%~6.72%。全扫描模式下,苯甲醚的检出限为0.3μg/L。实验结果表明,该方法快速、简便、灵敏度高,方法精密度和准确度均能满足水中微量及痕量苯甲醚检测的要求。

浅谈固相微萃取的理论和条件优化

固相微萃取是一种简便高效的方法,无需使用任何有机或化学试剂,即可实现对液相或顶空的挥发性或非挥发性物质的高选择性富集。SPME是一种与GC、HPLC联用技术相结合、具有广泛的分析线性范围等优点。本项目拟采用高效液相色谱-质谱联用技术,通过调控色谱柱的极性、膜厚、连续采样等多种方法,实现对样品中微量目标化合物的高纯度、高稳定性的检测。

Optimization and Application of Liquid Chromatography Determination of Dispersive Liquid-liquid Microextraction Purified Astaxanthin in Shrimp Waste

A new molecularly imprinted solid-phase extraction（MISPE） monolithic cartridge was synthesized, and MISPE-DLLME（DLLME=dispersive liquid-liquid microextraction） was developed for purification of astaxanthin in shrimp waste. The eluent（methanol） from MISPE was used as the dispersive solvent in subsequent DLLME for further purifying and enriching the analyte prior to high-performance liquid chromatography（HPLC） analysis. The mobile phase was methanol-acetonitrile-water-dichloromethane（85：5：5：5, volume ratio）, flow rate was 0.7 mL/min and UV wavelength was 476 nm. Under optimal conditions, good linearity was obtained in a range of 0.2--200.0 lug/mL（r2=0.9998） with a limit of detection（LOD） of 0.08 Hg/mL, and the extraction recoveries at three spiked levels ranged from 88.3%--92.5% with a relative standard deviation（RSD） less than 4.3%. Moreover, the mean contents of astaxanthin in the three batches of shrimp waste were 95.9, 85.4 and 77.2 μg/g, respectively. This method combining the advantages of MISPE and DLLME results in high selectivity and low cost, which was applied to determining the astaxanthin level in shrimp waste samples.

A microextraction approach for rapid extraction and separation of Mn(Ⅱ) and Co(Ⅱ) using saponified D2EHPA system

In this paper,we proposed a microextraction approach for the extraction and separation of Mn(Ⅱ)and Co(Ⅱ)from sulfate solution simulating leachate of spent lithium-ion battery cathode materials using saponified di-(2-ethylhexyl)phosphoric acid system.The effects of the following operational variables were investigated:equilibrium pH,tri-«-butyl phosphate concentration,saponification rate,two-phase ratio and residence time.The results showcased that the microextractor can reach the extraction equilibrium within 20 s,thereby greatly reducing necessary extraction time comparing to that of conventional processes.The volumetric mass transfer coefficient showed 8-21 times larger than that of batch device.With the help of microextractor,95%of Mn(Ⅱ)was extracted with a single theoretical stage at a chosen two-phase ratio of 3:1,and the separation factor β_(Mn/Co) was as large as 65.5.In the subsequent stripping step,more than 99%of manganese from loaded phase was easily stripped under optimal conditions.The microextraction approach greatly enhances the mass transfer while enabling a continuous and controllable extraction process within a simple structure design.When extracting spent electrode material with microextractors,the comprehensive recovery of mangenese can reach 96%.The microextraction approach has a good applicability in the spent lithium-ion battery cathode materials recycling at both bench and industrial scales.

基于静电纺丝纤维的固相萃取和固相微萃取技术在食品安全分析中的研究进展

食品安全分析技术发展对提升食品安全监管能力、确保食品安全具有重要的支撑。近年来,固相萃取和固相微萃取方法在低浓度、复杂基质的食品安全分析领域发挥着重要作用。静电纺丝作为一种纳米材料制备方法,具有操作简便、条件温和、制备高效、易于工业化生产等特征,在新材料研发领域备受关注。近年,以静电纺丝材料为固相萃取和固相微萃取吸附剂的研究取得了较多新的进展,也开始应用于食品安全分析领域。本文总结了食品安全分析领域中基于静电纺丝纤维的固相萃取和固相微萃取技术的研究及应用进展,讨论了现有研究中静电纺丝材料在吸附剂中的应用及相关前处理方法的优势,以期为以静电纺丝纤维为吸附剂的固相萃取和固相微萃取技术在食品安全分析领域的进一步研究提供参考。

泡腾辅助微萃取技术的开发与应用研究进展

泡腾辅助微萃取(EAM)技术是一种利用CO_(2)供体和H^(+)供体反应产生CO_(2)气泡促进萃取剂快速分散、增大与目标物的接触面积,以实现高效萃取的新型样品预处理手段。该技术具有分散速率快、萃取效率高、使用成本低、应用范围广等优点。得益于萃取剂的快速发展,泡腾辅助微萃取方法的构建和应用范围研究日趋完善和多样,已广泛用于环境、食品、生物等样品的前处理领域。该前处理技术结合各类检测仪器构建新型快速的检测方法,成功实现了重金属离子、农药、内分泌干扰物、抗生素等污染物的检测。在EAM技术的构建中,常考查泡腾片剂的组成、溶液pH、萃取温度、萃取剂种类、萃取剂添加量、洗脱剂种类、洗脱剂体积、洗脱时间、循环使用次数等因素对方法的影响,重点依据线性范围、相关系数、富集因子、检出限、定量限等参数对方法进行评判,最后结合各类仪器检测方法,实现在实际样品检测中的应用。该文从EAM技术常用的萃取剂方面入手,综述了基于纳米材料、离子液体等新兴萃取剂的EAM方法的构建,以及与液相色谱、气相色谱、原子吸收光谱或质谱等大型仪器联用,用于复杂基质中有害物质检测的研究与应用进展,分析了该技术在使用过程中存在的问题,展望了其未来在微萃取领域中的发展趋势。