Determination of urinary 8-hydroxy-2′-deoxyguanosine by capillary electrophoresis with molecularly imprinted monolith in-tube solid phase microextraction

Urinary 8-hydroxy-2 -deoxyguanosine(8-OHdG) is an excellent marker of oxidative DNA damage.In this study,employing guanosine as dummy template a novel molecularly imprinted(MIP) monolithic capillary column had been synthesized,and that was used as medium of in-tube solid phase microextraction(SPME).Coupled with capillary electrophoresis-electrochemical detection(CE-ECD),the system of extraction and detection of 8-OHdG in urinary sample had been developed.Because of its greater phase ratio combined with conv...

Solid phase microextraction chemical biopsy tool for monitoring of doxorubicin residue during in vivo lung chemo-perfusion

Development of a novel in vivo lung perfusion(IVLP)procedure allows localized delivery of high-dose doxorubicin(DOX)for targeting residual micrometastatic disease in the lungs.However,DOX delivery via IVLP requires careful monitoring of drug level to ensure tissue concentrations of this agent remain in the therapeutic window.A small dimension nitinol wire coated with a sorbent of biocompatible morphology(Bio-SPME)has been clinically evaluated for in vivo lung tissue extraction and determination of DOX and its key metabolites.The in vivo Bio-SPME-IVLP experiments were performed on pig model over various(150 and 225 mg/m^(2))drug doses,and during human clinical trial.Two patients with metastatic osteosarcoma were treated with a single 5 and 7 μg/mL(respectively)dose of DOX during a 3-h IVLP.In both pig and human cases,DOX tissue levels presented similar trends during IVLP.Human lung tissue concentrations of drug ranged between 15 and 293 μg/g over the course of the IVLP procedure.In addition to DOX levels,Bio-SPME followed by liquid chromatography-mass spectrometry analysis generated 64 metabolic features during endogenous metabolite screening,providing information about lung status during drug administration.Real-time monitoring of DOX levels in the lungs can be performed effectively throughout the IVLP procedure by in vivo Bio-SPME chemical biopsy approach.Bio-SPME also extracted various endogenous molecules,thus providing a real-time snapshot of the physiology of the cells,which might assist in the tailoring of personalized treatment strategy.

Analysis of α, β, γ-hexachlorocyclohexanes in water by novel activated carbon fiber-solid phase microextraction coupled with gas chromatography—mass spectrometry

A fast and simple method for determination of α, β, γ-hexachlorocyclohexanes (HCHs) in water using activated carbon fiber-solid phase microextraction(ACF-SPME) were studied. Results showed the performance of adsorption and desorption of three HCHs on ACF were excellent. A wide linear range from 10 to 100 μg/L and detection limits of the ng/L level were obtained using ACF-SPME with GC-MS in selected ion monitoring(SIM) acquisition mode. The proposed method was also successfully applied for determination of three HCHs in tap water. Compared to commercial fibers, ACF showed some advantages such as better resistance to solvents, higher thermal stability, longer lifetime and lower cost. The data demonstrated that GC-MS with ACF-SPME is well suitable for the analysis of HCHs in water.

A novel fiber coating for solid phase microextraction and its application for the extraction of n-alkane from aqueous sample

Base on the previous work in laboratory, a novel polyaniline doped with polydimethylsiloxane coating was developed on a stainless steel wire for solid phase microextraction（SPME） by electroplating method. This electroplating method not only has advantages of ease preparation and simple equipments required, but also increases the lifetime of the SPME fiber. The composite fiber（polyaniline/ polydimethylsiloxane（PANI/PDMS）） was evaluated by analyzing n-tridecane, n-tetradecane and n-pentadecane in aqueous sample. The new fiber coating showed comprehensive abilities to extract alkanes compounds. The relative standard deviations were found to be 6.8%-10.33%.

Porous covalent organic frameworks-improved solid phase microextraction ambient mass spectrometry for ultrasensitive analysis of tetrabromobisphenol-A analogs

Owing to frequent environmental monitoring of tetrabromobisphenol-A(TBBPA)analogs and their potential ecotoxicological effects on organisms,analysis of trace levels of TBBPA analogs with more non-polar and less water-soluble characteristics is of great significance for studying their environmental behaviors and toxic effects.Herein,a fast and sensitive technique is developed for directly detecting aqueous TBBPA analogs,including TBBPA mono(allyl ether)(TBBPA-MAE),TBBPA mono(2,3-dibromopropyl ether)(TBBPAMDBPE),TBBPA mono(2-hydroxyethyl ether)(TBBPA-MHEE)and TBBPA mono(glycidyl ether)(TBBPAMGE),by combining solid phase microextraction(SPME)based on porous covalent organic frameworks(Porous-COFs)with constant flow desorption ionization-mass spectrometry(CFDI-MS).As chromatographic separation is replaced by constant flow desorption,each sample can be analyzed within 7 min.The hierarchical porous structures(microporous,mesoporous and macroporous)of COFs lead to the enhanced mass transfer and the easier accessibility of active sites to TBBPA analogs,so that the extraction efficiency is 2.3-3.6 times higher than pure microporous COFs,and far superior to commercial coatings.The detection limit and quantification limit of this method are 0.1-1 and 0.4-3.2 ng/L,respectively.Ultratrace levels of TBBPA analogs from 5.0 ng/L to 66 ng/L have been successfully detected in river and sea water samples,showing great potential for subsequent studies of their environmental behaviors and toxicological effects.

姜花香气成分的SPME-GC-MS分析

姜花原产我国南部、西南部,印度、马来西亚也有分布,姜花为姜科姜花属多年生草本植物,其花香芬芳纯正,沁人心脾,很受人们喜爱.姜花清芬宜人,早已成为提取芳香油的工业原料,用以制备高级化妆品.……

固相微萃取GC-MS快速分析火场残留物中汽油成分

火场残留物如碳灰、烧残物等通常经过样品预处理后进行分析鉴定.传统的样品预处理方法往往操作繁琐、费时、重复性差,而且需用大量有机溶剂,不利于分析人员的身体健康,对环境也会造成一定污染.……

Changes of Aroma Components in Hongdeng Sweet Cherry During Fruit Development

To study the changes of aroma components in sweet cherry during fruit development, the aroma components in sweet cherry fruit from the green stage, the color stage, the commercial stage, and the ripe stage were collected using head-space solid phase microextraction （HS-SPME）, and were analyzed using a gas chromatograph-mass spectrophotometer （GC- MS）. A total of 37 compounds were identified from the sample extracts. Aldehydes, alcohols, and esters were the major constituents. The aroma components behaved differently during the fruit developmental period. C6 aldehydes and aromatic aldehydes were the main aldehydes in the sweet cherry fruit. The contents of C6 aldehydes increased quickly to 84.16% in the color stage, then decreased as ripening proceeded, and then, the contents decreased to 59.20 and 55.58% at the commercial stage and the ripe stage, respectively. The aromatic aldehydes （benzaldehyde） increased as ripening proceeded, and the maximum was found at the ripe stage. Alcohols of sweet cherry fruit included C6 alcohols and aromatic alcohols. The content of （E）-2-hexen-l-ol increased as ripening proceeded. The maximum was found at the commercial stage; alcohol was only found at the ripe stage. Ester components included ethyl acetate, butanoic acid ethyl ester, hexanoic acid ethyl ester, which increased as the fruit ripened. Hexanal, （E）-2-hexenal, benzaldehyde, （E）-2-hexen-l-ol, ethyl acetate, and hexanoic acid ethyl ester were the characteristic aroma components of sweet cherry fruit. These aroma components started to form drastically at the color stage, and the main aroma was formed at the commercial stage, which then turned bad at the ripe stage because of the presence of alcohol. So the optimal harvest time of sweet cherry was at the commercial stage.

Analyses of BioVOCs variation related to vegetation predominance in the Natural Park of Ampezzo Dolomites, UNESCO world heritage area of Dolomites

The determination of emitted Biogenic Volatile Compounds （BioVOCs） profile via Field Air Analysis （FAA） - Solid Phase Micro Extraction （75μm Carboxen/PDMS portable field sampler） was performed using GC-MS. The six sampling sites located in the Natural Park of Ampezzo Dolomites, part of the UNESCO＇s World Heritage List, are characterized by different predominating vegetation. The ubiquitous compound hexanal was chosen as internal standard, in order to compare the amounts of the different compound in the different sites. The main terpenes identified were α-pinene, 13-pinene, 6-3-carene and d-limonene, while 1,8 cineole was the highest abundant oxygenated terpene. In the site next the＇national road a higher amount of benzene derivatives （ben- zene, toluene, o-xylene, p-xylene and ethylbenzene） were observed. In the site relatively close to the road a marked decrease of benzene deriva- tives was observed. In the sites close to conifers （i.e. Fir, Pine and Larch） the terpenic content observed was higher than in the site close to the mixed forest （mainly large-leaf and some conifers）. Some terpenes were observed also in the high-quote meadow site, although of lower abun- dance than in the other sites. The highest abundance of terpenes was ob- served in the Pinus cerebra （Swiss Pine） site.

Metabolomic fingerprinting of porcine lung tissue during pre-clinical prolonged ex vivo lung perfusion using in vivo SPME coupled with LC-HRMS

Normothermic ex vivo lung perfusion(NEVLP)has emerged as a modernized organ preservation technique that allows for detailed assessment of donor lung function prior to transplantation.The main goal of this study was to identify potential biomarkers of lung function and/or injury during a prolonged(19 h)NEVLP procedure using in vivo solid-phase microextraction(SPME)technology followed by liquid chromatography-high resolution mass spectrometry(LC-HRMS).The use of minimally invasive in vivo SPME fibers for repeated sampling of biological tissue permits the monitoring and evaluation of biochemical changes and alterations in the metabolomic profile of the lung.These in vivo SPME fibers were directly introduced into the lung and were also used to extract metabolites(on-site SPME)from fresh perfusate samples collected alongside lung samplings.A subsequent goal of the study was to assess the feasibility of SPME as an in vivo method in metabolomics studies,in comparison to the traditional inlab metabolomics workflow.Several upregulated biochemical pathways involved in pro-and antiinflammatory responses,as well as lipid metabolism,were observed during extended lung perfusion,especially between the 11th and 12th hours of the procedure,in both lung and perfusate samples.However,several unstable and/or short-lived metabolites,such as neuroprostanes,have been extracted from lung tissue in vivo using SPME fibers.On-site monitoring of the metabolomic profiles of both lung tissues through in vivo SPME and perfusate samples on site throughout the prolonged NEVLP procedure can be effectively performed using in vivo SPME technology.

Changes of Aroma Components in 'Keitt' Mango during the Postharvest Period

[ Objective] This study aimed to investigate the ehangos of aroma components in mango fruit at different post-harvest stages. [ Method] The aroma com- ponents in ＇ Keitt＇ mango fruit at 3,6, 9 and 13 d postharvest were extracted using heM-space solid phase mieroextraction （HS-SPME） and analyzed by gas chre- matograph-rnass speetrephotometer （GC-MS）. [ Result] The results showed that a total of 42 aroma compounds were identified from the mango samples at four sta- ges. To be specific, monoterpene and sesquiterpene were the major components; at 3, 6, 9 and 13 d postharvest, the relative contents of terpene were 94.24%, 98.91%, 55.32% and 95.97%, respectively. [ Conclusion] IS-（ ＋ ）-3-earene is the characteristic aroma component in ripe fruit of ＇ Keitt＇ mango. The aroma of mango fruit is also affected by ester, alcohol and aldehyde compounds.

Estimation of the Postmortem Interval Using Chromatographic Fingerprints of Volatile Organic Compounds from Muscle

Estimation of the postmortem interval(PMI)is a crucial task in the field of forensic pathology and has unfortunately not been properly resolved.In this study,we analyzed volatile organic compounds(VOCs)in rat muscle samples collected at different PMIs and studied the feasibility of muscle VOC fingerprinting as a new method for PMI estimation.In total,110 rats were sacrificed and stored at a constant temperature(25℃).Rat skeletal muscle samples were collected at 0-10‑day postmortem,and then the VOCs were determined using a method of headspace solid‑phase microextraction coupled with gas chromatography‑mass spectrometry.The correlations between the VOCs(species and quantities)and PMIs were carefully analyzed and standard muscle VOC fingerprints at 25℃were established for different PMIs.To further test the accuracy of muscle VOC fingerprinting as a method for PMI estimation,ten additional rats with known PMIs were studied.We identified 15 kinds of VOCs and the number of VOC species increased with the PMI.The total peak areas of the VOCs increased significantly with the postmortem day(adjusted R^(2)=0.96-0.97).The mean error of the VOC fingerprinting for PMI estimation was 0.5 days and the mean relative error was 8.33%.We concluded that muscle VOC fingerprinting combining the use of VOC species and peak areas is accurate and effective and could be used as an alternative approach for PMI estimation in forensic practice.Although the preliminary results are encouraging,further studies in human cadavers under real case conditions are needed.