Determination of Dichlofluanid Residue in Soybean by Capillary Collumns Gas Chromatography

A method for the determination of dichlofluanid residue by Capillary Collumns Gas Chromatography was established in this study.Samples were extracted with acetone and subjected to through liquid-liquid extraction with N-hexane,and then they were cleanup with column that filled with florisil,subsequently separated by Capillary Column Gas Chromatography,and the electron capture detector （ECD） was used for detection.The detection limit of this method was 0.005 mg/kg （S/N=3）,and this method was rapid,sensitive and accurate,and was applied in the determination of dichlofluanid residue in soybean.

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.

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.

Retention behaviors of novel ionic liquid stationary phases and their selectivity for capillary gas chromatography

One chloride-terminated ionic liquid（CTIL） and two hydroxyl-terminated ionic liquids（HTILs） were synthesized and used as stationary phases for capillary gas chromatography（CGC）.Molecular interactions of these stationary phases were evaluated by Abraham solvation parameter model,indicating that the CTIL exhibits remarkably strong H-bond basicity and the HTILs possess both H-bond basicity and acidity.The molecular interactions were further confirmed by separation of a complex mixture consisting of ketones,aldehydes,esters,alcohols and aromatic compounds.It was found that the obtained solvation parameters correlate well with the chromatographic performances of the analytes in terms of elution order and resolution.The well correlated relationship between the solvation parameters and the selectivity of the CTIL and HTILs stationary phases is quite helpful in predicting and understanding the retention behaviors of different types of analytes on these stationary phases.

Selectivity of guanidinium ionic liquid for capillary gas chromatography

A guanidinium ionic liquid,N,N,N＇,N＇-tetrahexyl-N＂,N＂-dimethylguanidinium bis（trifluoromethane）sulfonylimide（THDMGNTf2）, was synthesized and used as stationary phase for capillary gas chromatography.In comparison with imidazolium ionic liquid stationary phase,the present new stationary phase exhibits quite different selectivity and behaves more like a low polar stationary phase.The guanidinium ionic liquid of THDMG-NTf2 exhibited better separation of Grab test mixture than imidazolium ionic liquid of 1-octyl-3-butylimidazolium bis（trifluoromethane）sulfonylimide（OBIM-NTf2）.Solvation parameter model was also used to evaluate the selectivity of THDMG-NTf2.Additionally,essential oil of Magnolia biondii Pamp was analyzed to further evaluate the selectivity of THDMG-NTf2 for a sample of complicated components.Satisfactory separation of the essential oil was achieved on a THDMG-NTf2 column（10 m） while using a commercial column（30 m） as reference.The present study shows that the guanidinium ionic liquid possesses novel chromatographic selectivity and has great potential for wide applications.

CAPILLARY GAS CHROMATOGRAPHIC ANALYSES OF THE PETROLEUM HYDROCARBONS IN COASTAL SEAWATER

This study of the petroleum hydrocarbons in coastal seawater, using dichloromethane extraction withO-terphenyl and n-C20 as internal standards, and gas chromatography with silica-capillary-column showedthat the recovery of petroleum hydrocarbons reaches 87.8% and that the lowest detection limit is 0.96μg.This method is reproducible, highly accurate, and applicable for determining the petroleum hydrocarbonsin coastal seawater.

Determination Enantiomer Excess(e.e.%)of Chiral Sharpless Epoxides with β-Cyclodextrin Derivatives as Chiral Stationary Phases of Capillary Gas Chromatography

Using four β-cyclodextrin derivatives, 2,6-di-O-benzyl-3-O-heptanonyl-β-CD, 2,6-di- O-benzyl-3-O-octanonyl-β-CD, 2,3-di-O-benzyl-6-O-heptanonyl-β-CD, and 2,3-di-O-benzyl -6-O- octanonyl-β-CD, as chiral stationary phases of capillary gas chromatography （CGC）, the enantiomers of Sharpless epoxides were well separated. The enantiomer excess values （e.e.%） of some chiral Sharpless epoxides were also determined successfully using these CDs.

SIMULTANEOUS DETERMINATION OF EPHEDRINE AND ITS ANALOGUES IN URINE BY CAPILLARY GAS CHROMATOGRAPHY

A method is developed for the simultaneous determination of ephedrine,pseudoephedrine, norephedrine, norpseudoephedrine and methylephedrine in urine on a capillary column using nitrogen-phosphorus detector.Diphenylamine is used as the internal standard.Calibration graphs are linear down to 1.30ug/ml urine.

A NOVEL DERIVATIVE OF β-CYCLODEXTRIN AS CHIRAL SIATIONARY PHASE IN CAPILLARY GAS CHROMATOGRAPHY

A novel β-cyclodextrin derivative, 2, 6-di-O-butyl-3-O-acetyl-β-cyclodex- trin, was prepared and used as chiral stationary phase for capillary gas chromato- graphic resolution of enantiomers, lhe glass capillary columns with the derivative having low melting point and high thermal stability could produce more than 3000 plates per column meter and have proven to be good chlral columns to separate the enantiomers of some amino acids, derivatives of epoxy ethane and alkyl halide, etc.

ANALYSIS OF VOLATILE CONSTITUENTS OF CHINESE MEDICINAL HERBS BY FLASH DISTILLATION/CAPILLARY GAS CHROMATOGRAPHY/MASS SPECTROMETRY

In present work,the volatile constituents of Curcuma longa L.,A.lancea (Thunb.) DC.,Foeniculum vulgare Mill,and Cinnamomun cassia Presl.have been analyzed by flash distillation/capillary gas chro-matography/mass spectrometry.The results are consistent with those obtained by conventional steam distillation extraction method.The optimum condition of flash distillation has been studied.The experimental results showed that this new technique proved to be a simple,rapid and efficient tool for microanalysis of volatile constituents of Chinese medicinal herbs.

Polysiloxane with Pendant [60]Fulleropyrrolidines as Stationary Phase for Capillary Gas Chromatography

Polysiloxane with pendant [60] fulleropyrrolidines was synthesized and used as the stationary phase for capillary gas chromatography for the first time. A preliminary investigation of its property shows that it has an excellent thermostability and a wide range of allowable operating temperature from 80 degrees C to 360 degrees C.

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.

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.

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.

Silylated and acetylated β-cyclodextrins for gas chromatographic stationary phases

Two new chiral stationary phases, 2,3 di O acetyl 6 O trimethylsilyl β cyclodextrin (DATBCD) and 2,6 di O trimethylsilyl 3 O acetyl β cyclodextrin(DTABCD), were synthesized, their structures were identified by means of infrared and NMR spectra. Capillary columns were coated with the two stationary phases by dynamic method. The chromatographic properties, and enantiomers separation, such as ketone, esters, alcohols and olefines, were investigated on the silylated and acetylated β cyclodextrin stationary phases. The experimental results show that the silylated and acetylated β cyclodextrins are suitable to be used as capillary gas chromatographic stationary phases, the relative polarity of DATBCD and DTABCD stationary phases is respectively 4143 and 3928, the column efficiencies are respectively 3084 and 4198, and DATBCD is of stronger enantioselectivity than DTABCD, capacity factor of the first eluted enantiomer ( k 1) and separation factor(α)of α phenylethanol on DATBCD stationary phase are respectively 8.23 and 1.019.

The Enantiomer Separations of Allethrone and Propargyllone Using Two Long Chain Acylated b-Cyclodextrin Derivatives as CGC Capillary Stationary Phases

Using two b-cyclodextrin derivatives (CDs) with long chain of acyl groups as chiral stationary phases (CSPs) of capillary gas chromatography (CGC), the enantiomers of racemic allethrone and propargyllone were well resolved after derived with acetyl chloride. The enantiomer excess values (e.e.%) of 1S-allethrone and 1S-propargyllone were also determined successfully using these CDs.

Determination of Camylofin Dihydrochloride and Nimesulide in Pharmaceutical Preparation by Gas Chromatography

This research paper describes simple analytical method for determination of Camylofin dihydrochloride and Nimesulide in tablet formulation by Gas chromatography method. Benzoic acid was used as internal standard. Validation was carried out in compliance with the International Conference on Harmonization guidelines. The method utilized GC (Agilent Technologies 6890 N Network GC system with FID detector), and RTX-5 capillary column (5% diphenyl-95% dimethyl polysiloxane), 30 m × 0.53 mm, 1.5 μm as stationary phase. Helium was used as the carrier gas at a flow rate of 1.5 mL?min–1. The proposed method was validated for linearity, LOD, LOQ, accuracy, precision, ruggedness and solution stability. It can be conveniently adopted for routine quality control analysis.

Alkylated and silylated β-cyclodextrin for gas chromatographic chiral stationary phases

Three new chiral stationary phases, 2,6 di O heptyl 3 O trimethylsilyl β cyclodextrin(DHTBCD), 2,6 di O pentyl 3 O trimethylsilyl β cyclodextrin (DPTBCD) and 2,6 di O butyl 3 O trimethylsilyl β cyclodextrin (DBTBCD), were synthesized. Chromatographic properties such as column efficiency, thermal stability and column life span, were studied. The separations of enantiomers, such as ketone, esters, alcohols and olefines, were investigated on the alkylated and silylated β cyclodextrin stationary phases. The influence of diluent on chiral separation was studied. The experimental results indicate that the stationary phases show good chromatographic properties in separating enantiomers. It is observed that inclusion complexation and hydrogen bonding interaction hardly play a role in separating enantiomers.

SFE-CGC测定藿香正气软胶囊中厚朴酚、和厚朴酚的含量

目的 :测定藿香正气软胶囊 (藿香油 ,紫苏油 ,陈皮 ,厚朴等 )中厚朴酚、和厚朴酚的含量。方法 :样品经超临界流体萃取后 ,用毛细管气相色谱测定含量。结果 :厚朴酚的平均回收率为 96 .81% (RSD =2 .81% ,n =5 ) ;和厚朴酚为 97.75 % (RSD =2 .36 % ,n =5 )。结论 :方法简便、快速。

沙棘籽油中维生素E含量的CGC法测定

目的:研究沙棘籽油中脂肪酸成分,定量分析并建立毛细管气相色谱法(CGC)测定沙棘籽油中维生素E(Vit E)含量的方法。方法:采用溶剂回流提取法提取沙棘油中挥发油成分,并用气相色谱-质谱联用法(GC-MS)对其进行定性、定量分析。采用岛津GC-2010 plus气相色谱仪,以正三十二烷为内标物对Vit E进行测定,并对该方法进行方法学考察。结果:从沙棘籽油中分离鉴定出28个化合物;采用Rtx-5毛细管色谱柱(30 m×0.25 mm,0.25μm);柱温为程序升温:150℃保持13 min,以10℃·min(-1)的升温速率升至300℃,保持8 min;FID检测器温度为300℃;进样口温度为310℃;无分流进样。在此条件下,Vit E和内标物分离良好,在0.02~0.43 mg·m L(-1)浓度范围内呈良好线性关系,r=0.999 6。结论:建立以CGC测定沙棘籽油中维生素E含量的方法,灵敏、准确、重复性好,可作为沙棘籽油中Vit E的含量测定方法。