Determination of 14 Organophosphorus Pesticide Residues in Mutton by Gel Permeation Chromatography-Gas Chromatography-Mass Spectrometry(GPC-GC-MS)

[Objectives]This study was conducted to purify mutton samples by gel permeation chromatography(GPC).[Methods]Fourteen organophosphorus pesticide residues in samples were qualitatively and quantitatively analyzed by gas chromatography-mass spectrometry(GC-MS)in selective ion scanning mode(SIM).[Results]The organophosphorus pesticide standard solutions showed good linearity in the mass concentration range of 0.1-10.0μg/ml with correlation coefficients(r)not lower than 0.999,and the detection limits(S=3 N)ranged from 0.01 to 0.05 mg/kg.The average recovery values were in the range of 80.2%-99.7%,with relative standard deviations(RSDs,n=3)in the range of 1.8%-6.3%,at the addition levels of 0.5,1.0 and 2.0 mg/kg.[Conclusions]The method is simple,sensitive and accurate,and can be used for the determination of organophosphorus pesticide residues in mutton.

GAS6-AS1调节miR-370-3p/SPATA2轴对卵巢癌细胞增殖、迁移、侵袭、凋亡和EMT的影响

目的:探讨长链非编码RNA GAS6反义RNA1(long non-coding RNA GAS6 antisense RNA1, lncRNA GAS6-AS1)调节miR-370-3p/精子发生相关蛋白2 (spermatogenesis-associated protein 2, SPATA2)轴对卵巢癌细胞增殖、迁移、侵袭、凋亡和上皮间质转化(epithelial mesenchymal transformation, EMT)的影响。方法:qRT-PCR、Western blot分别检测癌旁组织、卵巢癌组织、人正常卵巢上皮细胞IOSE80及卵巢癌细胞系HO-8910、SKOV3、A2780中GAS6-AS1、miR-370-3p及SPATA2蛋白表达。将SKOV3细胞分为:对照组(NC组)、 si-NC组、si-GAS6-AS1组、mimic NC组、miR-370-3p mimic组、si-GAS6-AS1+inhibitor NC组、si-GAS6-AS1+miR-370-3p inhibitor组,qRT-PCR检测细胞中GAS6-AS1、miR-370-3p表达;CCK-8法检测细胞增殖;流式细胞术检测细胞凋亡;划痕愈合实验检测细胞迁移;Transwell实验检测细胞侵袭;Western blot检测SPATA2、细胞周期素D1(CyclinD1)、Bcl-2相关X蛋白(Bcl-2-associated X,Bax)、E-钙黏蛋白(E-cadherin)、波形蛋白(Vimentin)、神经钙黏蛋白(N-cadherin)表达;双荧光素酶报告基因实验检测GAS6-AS1与miR-370-3p、 miR-370-3p与SPATA2的关系。结果:在卵巢癌组织和细胞中GAS6-AS1、SPATA2蛋白高表达,miR-370-3p低表达,且在SKOV3细胞中GAS6-AS1、SPATA2蛋白表达量最高,miR-370-3p表达水平最低,因此,选择SKOV3细胞为后续研究对象。与NC组、si-NC组比较,si-GAS6-AS1组GAS6-AS1、OD450值(24 h、48 h、72 h)、划痕愈合率、侵袭细胞数、SPATA2、CyclinD1、Vimentin、N-cadherin蛋白表达降低,miR-370-3p表达、细胞凋亡率、Bax、E-cadherin蛋白表达升高(P<0.05);与NC组、mimic NC组比较,miR-370-3p mimic组OD450值(24 h、48 h、72 h)、划痕愈合率、侵袭细胞数、SPATA2、CyclinD1、Vimentin、N-cadherin蛋白表达降低,miR-370-3p表达、细胞凋亡率、Bax、E-cadherin蛋白表达升高(P<0.05);miR-370-3p inhibitor减弱了沉默GAS6-AS1对SKOV3细胞增殖、迁移、侵袭及EMT的抑制及对细胞凋亡的促进作用。GAS6-AS1与miR-370-3p、miR-370-3p与SPATA2存在靶向调控关系。结论:沉默GAS6-AS1通过上调miR-370-3p来抑制SPATA2表达,从而抑制SKOV3细胞增殖、迁移、侵袭及EMT,并促进细胞凋亡。

lncRNA GAS5调控miR-452-5p/Mcl-1通路对急性肺损伤大鼠肺组织细胞焦亡的影响

目的探讨长链非编码RNA生长抑制特异因子5(lncRNA GAS5)调控miR-452-5p/髓样细胞白血病序列-1(Mcl-1)通路对急性肺损伤(ALI)大鼠肺组织细胞焦亡的影响。方法取SD大鼠随机分成6组(每组10只):对照组、模型组、pUC57-lncRNA GAS5组、miR-452-5p抑制剂组、pUC57-NC+miR-452-5p-NC组、pUC57-lncRNA GAS5+miR-452-5p激活剂组。模型组和各干预组大鼠以腹腔注射脂多糖的方法构建ALI模型,对照组大鼠腹腔注射等量生理盐水,造模同时进行分组干预。然后检测大鼠肺功能,比较各组用力肺活量(FVC)、0.3秒用力呼气容积(FEV0.3)/FVC、潮气量(VT);HE染色观察大鼠肺组织病理损伤,并以Holfbauer评分评估其损伤程度;酶联免疫吸附法(ELISA)测定大鼠肺泡灌洗液(BALF)和血清炎症因子白细胞介素(IL)-18、IL-1β水平;免疫印迹法检测大鼠肺组织焦亡相关指标[消皮素D(GSDMD)、核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)、天冬氨酸特异性半胱氨酸蛋白酶(Caspase)-1、Caspase-11]及Mcl-1蛋白表达;实时荧光定量PCR检测大鼠肺组织lncRNA GAS5、miR-452-5p及Mcl-1表达;双荧光素酶报告基因实验验证大鼠肺泡上皮细胞L2中lncRNA GAS5对miR-452-5p的靶向调节。结果与对照组比较,模型组大鼠FVC、FEV0.3/FVC、lncRNA GAS5表达、Mcl-1蛋白及mRNA表达降低(均P<0.05),VT、Holfbauer评分、IL-18及IL-1β水平、GSDMD、NLRP3、Caspase-1及Caspase-11蛋白表达、miR-452-5p表达升高(均P<0.05)。与模型组比较,pUC57-lncRNA GAS5组、miR-452-5p抑制剂组大鼠FVC、FEV0.3/FVC、Mcl-1蛋白及mRNA表达均升高(均P<0.05),VT、Holfbauer评分、IL-18及IL-1β水平、GSDMD、NLRP3、Caspase-1及Caspase-11蛋白表达、miR-452-5p表达均降低(均P<0.05);pUC57-NC+miR-452-5p-NC组大鼠各指标无显著差异(均P>0.05)。与pUC57-lncRNA GAS5组比较,pUC57-lncRNA GAS5+miR-452-5p激活剂组大鼠FVC、FEV0.3/FVC、Mcl-1蛋白及mRNA表达降低(均P<0.05),VT、Holfbauer评分、IL-18及IL-1β水平、GSDMD、NLRP3、Caspase-1及Caspase-11蛋白表达、miR-452-5p表达升高(均P<0.05)。结论lncRNA GAS5可通过靶向下调miR-452-5p而促进Mcl-1表达,进而抑制ALI大鼠炎症反应及肺组织细胞焦亡,最终减轻大鼠肺损伤并改善其肺功能。

LncRNA GAS5通过miR-182-5p/FOXF2轴对口腔鳞状细胞癌细胞增殖、凋亡、迁移及侵袭的影响

目的探讨长链非编码RNA生长停滞特异性转录本5(LncRNA GAS5)调节微小RNA-182-5p(miR-182-5p)/叉头盒蛋白F2(FOXF2)对口腔鳞状细胞癌(OSCC)细胞增殖、迁移、侵袭及凋亡的影响。方法收集45例确诊为OSCC的癌组织以及癌旁组织,体外培养人口腔上皮细胞系HOEC及人OSCC细胞系CAL-27、HSC-3、SCC-25,qRT-PCR检测组织、细胞中LncRNA GAS5、miR-182-5p、FOXF2的表达;择细胞株CAL-27分为ctrl组、pcDNA组、pcDNA-GAS5组、pcDNA-GAS5+miR-NC组及pcDNA-GAS5+miR-182-5p mimics组,采用CCK-8试剂盒检测细胞增殖活性,Transwell实验检测细胞迁移和侵袭能力,流式细胞术检测细胞凋亡水平,Western Blot检测癌细胞中FOXF2、bax、Bcl-2、cleaved caspase-3及E-cadherin蛋白表达,双萤光素酶报告实验验证miR-182-5p与LncRNA GAS5、FOXF2的关系。结果与癌旁组织相比,OSCC组织中LncRNA GAS5、FOXF2 mRNA表达降低,miR-182-5p表达升高(P<0.05);CAL-27、HSC-3、SCC-25细胞与HOEC相比,LncRNA GAS5、miR-182-5p、FOXF2表达趋势与OSCC组织内一致,且在CAL-27表达最明显,选择其作为后续实验的细胞株;与ctrl组、pcDNA组比较,pcDNA-GAS5组CAL-27细胞中GAS5、FOXF2 mRNA、细胞凋亡率及BAX、E-cadherin蛋白表达升高(P<0.05),miR-182-5p表达、细胞增殖、迁移和侵袭数及Bcl-2蛋白表达降低(P<0.05);上调miR-182-5p可减弱过表达LncRNA GAS5对CAL-27细胞增殖、迁移和侵袭的抑制作用,也可抑制癌细胞凋亡;LncRNA GAS5靶向负调控miR-182-5p表达,miR-182-5p靶向负调控FOXF2表达。结论上调GAS5可能通过抑制miR-182-5p来增加FOXF2表达,进而抑制CAL-27细胞增殖、迁移及侵袭,促进CAL-27细胞的凋亡。

Gas Chromatographic Method for Identification and Quantification of Commonly Used Residual Solvents in Pharmaceuticals Products

Background: Impurities are not expected in the final pharmaceutical products. All impurities should be regulated in both drug substances and drug products in accordance with pharmacopeias and ICH guidelines. Three different types of impurities are generally available in the pharmaceutical’s product specification: organic impurities, inorganic impurities, and residual solvents. Residual solvents are organic volatile chemicals used or generated during the manufacturing of drug substances or drug products. Purpose: The aim of this study is to develop a cost-effective gas chromatographic method for the identification and quantification of some commonly used solvents—methanol, acetone, isopropyl alcohol (IPA), methylene chloride, ethyl acetate, tetrahydrofuran (THF), benzene, toluene, and pyridine—in pharmaceutical product manufacturing. This method will be able to identify and quantify the multiple solvents within a single gas chromatographic procedure. Method: A gas chromatography (GC) equipped with a headspace sampler and a flame ionization detector, and a column DB 624, 30-meter-long × 0.32-millimeter internal diameter, 1,8 μm-thick, Brand-Agilent was used to develop this method. The initial GC oven temperature was 40°C and held for 5 minutes. It was then increase to 80˚C at a rate of 2˚C per minute, followed by a further increase to 225˚C at a rate of 30˚C per minute, with a final hold at 225˚C for 10 minutes. Nitrogen was used as a carrier gas at a flow rate of 1.20 mL per minute. Dimethyl sulfoxide (DMSO) was selected as sample solvent. Results: The developed method is precise and specific. The percent RSD for the areas of six replicate injections of this gas chromatographic method was within 10.0 and the recovery result found within 80.0% to 120.0%.

Classification of Chinese Traditional Drug-"Beimu" (Bulbus Fritillariae) by Pyrolysis High Resolution Gas Chromatography-Pattern Recognition

The combination of pyrolysis high resolution gas chromatography and pat- tern recognition techniques is a powerful tool for the classification of traditional Chinese drug.A study has been completed on 55 Beimu samples of five different geographic origins: Eastern China.Central China.South-western China,North-western China and North-eastern China.Principal component analysis and SIMCA are applied to effectively classifying the samples according to the origin of the plants.The chemical information contained in the high resolution gas chromatographic data is sufficient to characterize the geographic origin of sam- pies.

Determination of phthalate esters in fat-containing foods by packed nanofiber solid-phase extraction column and gas chromatography

A new method for simultaneous determination of four phthalate esters （ PAEs） in commercial fat-containing foods was developed by the combination of a packed nanofibers column based on solid-phase extraction with gas chromatography-flame ionization detector （ GC-FID ）. Conditions for obtaining optimum extraction efficiency such as extraction solvents, morphologies of adsorbent, ion strength and pH were investigated and optimized in detail. Under the optimized conditions, the limits of detection （LODs） found for dibutyl phthalate （DBP） , butyl benzyl phthalate （BBP）, diethyl hexyl phthalate （DEHP） and di-n-octyl phthalate （DNOP） were 50, 25, 50 and 25 ng/g, respectively. Good linearity of four PAEs was achieved in the range of 50 to 4 000 ng/g. The proposed method was applied for analyzing different kinds of fat-containing samples. PAEs in commercial fat-containing samples can be highly extracted by a packed solid-phase extraction column of 5 mg polystyrene （ PS） nanofibers. The satisfactory average recoveries were obtained in the range of 96. 7% to 102. 3% , and the relative standard deviations （RSDs） below 5% were achieved. The proposed method reduces the organic solvent consumption, the complex and tedious procedures for sample pretreatment, and achieves high sensitivity and reproducibility for the investigated PAEs.

Separation Properties of a New Polysiloxane-Anchored β-Cyclodextrin Derivative as Gas Chromatography Stationary Phase

A new capillary gas chromatography stationary phase, monokis (2,6 di O benzyl 3 O propyl (3’)) hexakis(2,6 di O benzyl 3 O methyl) β CD bonded polysiloxane, was synthesized. It exhibited separation abilities to disubstituted benzene isomers and some chiral solutes. It was also found that the polarity of CD derivatives can be lowered both by chemically bonding it to polysiloxane and by diluting it in polysiloxane. The separation abilities of the polysiloxane anchored CDs (SP CD) are higher than that of the unbonded CDs (S CD) and the diluted S CD at lower column temperature. Hydrosilylation reaction is one of the best methods to lower the operating temperature of CDs.

Pyrolysis-Gas Chromatography/Mass Spectrometry for Microstructure and Pyrolysis Pathway of Polyester-Polyether Multiblock Copolymer

The composition and sequence distribution of monomeric units in polyester polyether multiblock copolymer were studied by pyrolysis? gas chromatography (PGC) and pyrolysis gas chromatography/mass spectrometry (PGC/MS). PGC was applied to study the F t curve of the multiblock copolymer and PGC/MS was used to separate and identify the pyrolyzates. DTA experiment was used to study the decomposition temperature. The results show that the beginning point of elastomer’s decomposition was about 300?℃ and the decomposition temperature of most of the sample was 550?℃. Many pyrolyzates were produced because of the breaking of weak bonds in the sample. The possible microstructure was verified and the pyrolysis pathway of the copolymer was investigated.

Synthesis and Characterization of Peralkylated β-Cyclodextrins Used as Gas Chromatographic Stationary Phasest

Six peralkylated β- cyclodec\xtrins used as capillary gas chromatographic stationary phases were prepared and characterized by differential by differential scannning calorimetry(DSC) and pyrolysis gas chromatography (PyGC). The DSC profiles illustrated that the peralkylated β-cyclodextrins synthesized possess the supercoooled state and the glass state below their melting point The PYGC results showed that the long-chain alkylated β-cyclodextrins are more thermostable than the short-chain. one All ofthese peralkylated β-cyclodextrins are suitable for use as capillary column gas chromatographic stationary phases,which can easily be coatal on the fused silica capilary columns and have nice chromatographic retention behaviour. For example, the capillary colunns coated with these materials can excellently separate three methylphenol isomers and six dimehylphenol isomers.

Application of Pyrolysis-Gas Chromatography in Explosive and Propellant Analysis

Applications of pyrolysis-gas chromatography and pyrolysis capillary gas chromatography in explosive and propellant analysis are reviewed, including the identification of explosives and propel- lants, the investigation of the thermal decomposition of nitrocellulose (NC), cyclotetramethylene tetranitramine (HMX)and cyclotrimethylene trinitramine (RDX), and the study of the wear- reducing mechanism of polyurethane additive in propellant gain.

Enantioselective Determination of R-(-)-and S-(+)-Mexiletine in Microsomal Incubates by Capillary gas Chromatography

A method for the assay of R ( ) and S (+) mexiletine in rat liver microsomal incubates was developed. The method involved extraction of mexiletine from the microsomal incubates, and formation of mexiletine diastereomeric derivatives with a chiral reagent S ( ) N trifluoroacetyl prolyl chloride. Separation and quantitation of the diastereomeric mexiletine derivatives were carried out by a capillary gas chromatographic system with flame ionization detection. The assay was linear from 5 to 500 μg/ml for each enantiomer. The average recoveries of analytical method were 93 31±5 59% and 93 10±5 11% for R ( ) and S (+) mexiletine, respectively. The limits of detection and quantitation for the method were 1 0 μg/ml and 5 0 μg/ml for the R ( ) and S (+) mexiletine isomers, respectively. The reproducibility in the assay was better than 16.5% (RSD). The method has been applied to the metabolism study of R ( ) and S (+) mexiletine in rat liver microsomal incubates.

Cross-Linked Crown Ether-SE-54 as Stationary Phase for Open-Tubular Column Gas Chromatography

The cross-linking of crown ether-SE-54 in fused-silica capillary columns were initiated by dicumyl peroxide(DCUP),azo-bis-isobutyronitrile (AIBN)and ozone(O_3).Parameters of evaluation such as polarity,selectivity, phase transition temperature and thermal stability were studied and compared with those of poly(crown ether)stationary phase.

Extraction of essential oil from shaddock peel and analysis of its components by gas chromatography-mass spectrometry

Essential oil, with more than thirty kinds of compounds separated and identified by gas chromatography-mass spectrometry, was extracted from Shatian shaddock peel and Sweet shaddock peel by squeeze-steam distillation and direct steam distillation method. Among their composition, the main components are terpene compounds, which account for 93.926% (mass fraction, the same below) and 85.843% of essential oils extracted from Shatian shaddock peel and Sweet shaddock peel, respectively. Although nootkatone is the major contributor of shaddock characteristic scent, and its contents are 1.069% and 1.749% of essential oils from Sweet shaddock peel and Shatian shaddock peel, respectively. The results show that squeeze-steam distillation gives higher yield and good quality of essential oil and the compositions of essential oils from two kinds of shaddock peels are different, but the main contributors of the shaddock scent are the same.

Chromatoprobe as a sample-sparing technique for residual solvent analysis of drug discovery candidates by gas chromatography

In drug discovery research, residual solvent measurement is an integral part of purity analysis for synthesis of a drug candidate before it is used for toxicity testing. This is usually carried out using gas chromatography(GC)with direct injection sample introduction. This method requires testing compounds to be soluble at high concentrations( > 50 mg/mL, usually in DMSO) to achieve acceptable sensitivity, a hurdle which is not always achievable for some samples such as cyclic peptides and oligonucleotides. To overcome the limitation associated with the direct injection approach, a new method using the Chromatoprobe thermal extraction device was developed for quantifying residual solvents of drug discovery compounds. This method not only consumes significantly less material(less than 1 mg), but also shows higher sensitivity than the direct injection approach.In addition, because no diluent is required with the Chromatoprobe thermal extraction, all residual solvents can be detected and measured without further method optimization. In our study, we compared data from GC residual solvent analysis using the Chromatoprobe solid sample introduction to those of the direct injection method for seven in-house samples. Our results showed a good agreement between the data from these two sample introduction methods. Thus, the Chromatoprobe sample introduction method provided a samplesparing alternative to the direct injection method for the measurement of residual solvents in drug discovery.This method can be particularly useful for residual solvent analysis in samples that are available only in limited amounts, poorly soluble, and/or unstable in the diluents used for the direct injection method.

A study on α-ketoadipic aciduria by gas chromatographic-mass spectrometry

INTRODUCTIONα-ketoadipate(α-KA),an intermediate in thecatabolism of L-lysine,hydroxylysine,and L-tryptophan,undergoes oxidative deearboxylation toform glutaryl-CoA and then dehydrogenates to formcrotonyl-CoA,the latter undergoes furtherdegradation and enters in TCA cycle,as shown inFigure 1.α-ketoadipic aciduria (Mckusick 245130)is a rare inborn error in the metabolism of α-KA

Determination of Eight Organophosphorus Pesticide Residues in Pepper by QuEChERS-Gas Chromatography

[ Objectives] This study was conducted to establish a QuEChERS-gas chromatography method for determination of eight kinds of organophosphorus pesticide residues in pepper. [Methods] The samples were extracted by acetonitrile, and anhydrous magnesium sulfate was used for salting out. The extracts were then purified by dispersive solid phase extraction combining with GCB, C18 and PSA. Samples were analyzed by FPD detector. External standard was used as quantitive method. [ Results] The detection limits were in the range of 0. 001 -0. 008 mg/kg, the average recoveries ranged from 83.5% to 101.2% , and the relative standard deviation （RSD） of the eight organophosphorus pesticide residues were below 5%. [ Conclusions] The method is simple, quick, easy and effective for the determination of pepper.

Novel guanidinium-based ionic liquids as stationary phases for capillary gas chromatography

The present study describes guanidinium-based ionic liquids（GBILs） as stationary phases for capillary gas chromatography （CGC） and to the best of our knowledge,no related reports are available up to now.In this study,a hexaalkylguanidinium ionic liquid（DOTMG-NTf;） was synthesized and coated statically onto capillary columns.Selectivity of the stationary phase was evaluated by separating Grob test mixture,test mixture,alcohols mixture,and fatty acid methyl esters mixture,and thermal stability was investigated as well.The present study demonstrates that GBILs as CGC stationary phases exhibit satisfactory selectivity and thermal stability and have a great potential as new candidates for CGC stationary phases.

Capillary gas chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco

Simple procedures for extraction and chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco are described.The determination was carried out by capillary gas chromatography(GC) with electron capture detection(ECD) and confirmed by GC-MS.The mean recoveries and relative standard deviation(RSD) were 93.2%～112.9% and 3.5%～6.7%,respectively at levels ranging from 0.01 to 0.1 mg/kg.The limit of determination was 0.001 mg/kg.Tobacco samples in routine check were successfully analyzed using the proposed method.

Microwave Extraction Followed by Solid-phase Extraction for the Determination of Phthalate Esters in Fish Samples by Gas Chromatography

A new analytical procedure based on solid-phase extraction method coupled to GC-FID has been developed and validated for the determination of five phthalate esters （PAEs） （dimethyl-（DMP）, diethyl-（DEP）, di-n-butyl-（DBP）, di-2-ethylhexyl- （DEHP）, di-n-octyl-（DOP）） in fish samples. There was a good linear relationship in the range of 0.05-10μg with the detection limits of 0.09-0.16ng .The recoveries obtained for PAEs ranged from 88.6% to 96.4%with RSD of 4.2%-10.2%.The applicability of the developed method was demonstrated for real fish samples.