气相色谱法测定环己烷中甲酸

提出了测定环己烷中甲酸含量的气相色谱法,采用热导池检测器,癸二酸/GDX103不锈钢填充柱(2m×2mm),优化了色谱条件,测得检出限(3S/N)为11 0 mg·kg-1,甲酸的质量浓度在10.0～100.0 g·L-1范围呈线性关系,测得加标回收率在96.0%～104.3%之间,对20.0,100.0 g.L-1甲酸标准测定7次,相对标准偏差分别为3.2%和1.9%,符合环己烷工艺中甲酸含量测定的技术要求.     

气相色谱法测定食品工业抽提级正己烷中微量苯

采用Agilent7890A气相色谱开发出分析食品工业抽提级正己烷中微量苯含量低于100 mg/kg的新方法,完成一个样品分析只需18 min.该方法工作曲线线性相关系数为0.99998,回收率为94.93%～103.67%,使用条件要求样品终馏点不高于70 ℃,在实际使用过程中,分析结果准确、可靠、重复性好.     

毛细管气相色谱法测定鞋和箱包用胶粘剂中正己烷的含量

采用丙酮作为溶剂,选用19091N-213型毛细管色谱柱(30 m×0.32 mm i.d.,0.5μm)和氢火焰离子化检测器,以毛细管气相色谱法测定鞋和箱包用胶粘剂中正己烷含量。正己烷的浓度在0~1 000μg/mL与色谱峰面积成线性关系,线性回归方程为A=127 107c 383.26,相关系数r=0.999 1,检出限为0.003μg/mL,用该方法对胶粘剂样品进行测定,测定结果的相对标准偏差为2.8%~4.5%(n=5),加标回收率为96.4%~107.8%。     

气相色谱法分离和测定对甲硫基苯酚

采用气相色谱法分离和测定对甲硫苯酚.在Ф6×1.5×1500mm玻璃柱内填充5% OV 101/Chromosorb W-AW DMCS的色谱柱上,对甲硫基苯酚与内标物磷酸三丁酯及杂质之间具有较好的分离效果;而且以磷酸三丁酯为内标物时其重量校正因子相当稳定,即f_w.A=0.948±0.0054(n=9,α=0.05).该方法操作简便、快速、准确.对同一试样的8次平行独立测定其标准偏差为0.25,变异系数为0.0072.并且,该方法的3次加入法回收率达98.18%～99.22%.     

气相色谱法分离和测定环境空气中的丙烯酸乙酯和甲基丙烯酸甲酯

用活性炭吸附环境空气中的丙烯酸乙酯和甲基丙烯酸甲酯,经二硫化碳妥吸后用气相色谱法测定在填充２．５％ＤＮＰ＋２．５％Ｂｅｎｔｏｎｅ３４／ＣｈｒｏｍｏｓｏｒｂＷ ＨＰ ＤＭＣＳ的玻璃色谱柱上,丙烯酸乙酯与甲基丙烯酸甲酯及干扰物之间能较好地分离。方法的回收率：丙烯酸乙酯为８６．４％－１０３．０％,甲基丙烯酸甲酯为８６．３％－１０１．２％,变异系数：丙烯酸乙酯为４．１％－４．４％,甲基丙烯酸甲酯为４．４％     

气相色谱法检测盐酸氟西汀原料中氯仿和正己烷残留量

采用气相色谱法检测盐酸氟西汀原料中CHCl3和正己烷残留量。色谱柱:DB-17(50%二苯基/50%甲基硅氧烷,0.25mm i.d.×30m,0.25μm);载气:H2(30mL/min),AIR(350mL/min),Make up Const col(N2):35 mL/min;进样口温度:250℃;检测器温度:250℃;柱温:60℃;不分流模式;Split柱流速:2mL/min;进样量:1μL。正己烷在157.2~393.0ng范围内,CHCl3在5.88~117.6ng范围内,峰面积与浓度之间线性性关系良好。检出限:信噪比3∶1时,正己烷LOD:2.62ng;CHCl3LOD:2.94ng。定量限:信噪比10∶1时,正己烷LOQ:2.62ng;CHCl3LOQ:5.88ng。正己烷、氯仿理论塔板数分别为171513、206764。本法可检测盐酸氟西汀原料中有机溶剂残留量,为其质量控制提供依据。     

中空纤维顶空液相微萃取-气相色谱法测定胶黏剂中正己烷

建立了以中空纤维顶空液相微萃取(HF-HS-LPME)为样品前处理技术,结合气相色谱法测定胶黏剂中正己烷含量的方法。通过对萃取剂的选择、温度、时间、搅拌速率、盐效应等参数的优化,确定了最佳实验条件:以邻二甲苯作为有机萃取剂,萃取温度为80℃,萃取时间为45 min,搅拌速率为700 r/min,Na Cl加入量为4 mol/L。萃取后,取0.5μL接收相进行气相色谱分析。正己烷含量的标准曲线在0.0138~1.38 g/L范围内线性关系良好,相关系数为0.9995,相对标准偏差(RSD)为2.6%,方法的检出限(LOD)为89.2μg/L(经LPM E后LOD则可达5.2μg/L)。研究还发现,正己烷初始质量浓度在3.46~138 mg/L范围内时,富集倍数随正己烷初始浓度的增大呈对数型降低,这为LPM E的理论研究提供了新的论据。方法应用于胶黏剂样品分析,平均加标回收率为92.3%~96.2%,RSD为3.6%~4.7%。     

气相色谱法分离和测定环境空气中的丙烯酸乙酯和甲基丙烯酸甲酯

用活性炭吸附环境空气中的丙烯酸乙酯和甲基丙烯酸甲酯 ,经二硫化碳 (CS2 )解吸后用气相色谱法测定 .在填充 2 .5 %DNP + 2 .5 %Bentone 34/ChromosorbWHPDMCS的玻璃色谱柱 (长 2m内径 3mm)上 ,丙烯酸乙酯与甲基丙烯酸甲酯及干扰物之间能较好地分离 .方法的回收率 :丙烯酸乙酯为 86.4%～ 1 0 3.0 % ,甲基丙烯酸甲酯为 86.3 %～ 1 0 1 .2 % ,变异系数 :丙烯酸乙酯为 4.1 %～ 4.4% ,甲基丙烯酸甲酯为 4.4%～ 4.9% ,当采样体积为 2 0L ,解吸液体积为 2 .0 0mL ,进样 2 μL时 ,丙烯酸乙酯和甲基丙烯酸甲酯的最低检测浓度分别为 0 .0 2mg/m3和 0 .0 1mg/m3.     

气相色谱法分离检定血中八种氨基甲酸酯

采用国产Ｃ＿１８往固相提取血中八种氨基甲酸酯,用乙酸乙酯洗脱,用气相色谱分离检定,用气相色谱／质谱进行确证。此法灵敏度为１～２μｇ／ｍＬ血,最低检出限为２０～４０ｎｇ,回收率在６２～９２％之间。     

正癸烷和正己烷气相氧化裂解过程的研究

采用石英管反应器,常压下研究了正癸烷和正己烷的气相氧化裂解（GOC）过程。实验结果表明,O2的存在降低了正癸烷GOC反应的活化能,使反应在较低的温度下具有高的反应性能;O2同时起到消除积炭的作用,提高体系的抗积炭能力。于热裂解反应相比,低温下正癸烷的GOC反应更适合制备液体组分,同时联产低碳烯烃。在600℃,碳氧摩尔比为2.5时,正癸烷的GOC反应可获得39.9％的低碳烯烃收率和30.0％的液体收率。对于直链烷烃的GOC反应,低温下O2主要进行氧化脱氢反应,高温下则更多的进行 CO x(x=1,2)的生成反应;和正己烷分子相比,相同反应条件下O2更容易引发正癸烷分子的部分氧化反应生成CO。     

Modelling of GC and HPLC separations of simazin and atrazin by experimental design methodology

Summary Experimental Design methodology allows the modelling and optimization of the chromatographic separation of similar pesticides (triazine family) by GC and HPLC. The GC separation of simazin and atrazin is well modelled by a first degree equation, involving injected volume, carrier gas pressure and rising oven temperature. The LC is modelled by a second degree equation, depending on injected volume, eluent flow and composition. These calculated models allow easy optimization of the separations, using isoresponse curves.     

Use of Experimental Design to Develop a Method for Analysis of 1,3-Dichloropropene Isomers in Water by HS-SPME and GC–ECD

A simple and reliable method has been established for determination of cis and trans-1,3-dichloropropene (1,3-DCP) in water by headspace solid-phase microextraction (HS-SPME) then GC–ECD. An experimental design with two steps was performed to determine the best experimental conditions for extraction of the 1,3-DCP isomers. First, a 2⁶⁻² fractional factorial design was conducted to screen for significant conditions. Second, a central composite design (CCD) was performed to optimise the variables. The best experimental extraction conditions were: polydimethylsiloxane–divinylbenzene (PDMS–DVB)-coated fibre, 20-min extraction time, 12 °C extraction temperature, 300 g L⁻¹ NaCl, and 20 mL headspace volume in 40-mL vial. Under these conditions the method detection limit (MDL) was 0.5 ng L⁻¹ for cis-1,3-DCP and 1.0 ng L⁻¹ for trans-1,3-DCP. The method quantification limit (MQL) was 1.2 ng L⁻¹ for cis-1,3-DCP and 3.0 ng L⁻¹ for trans-1,3-DCP. For both isomers the relative standard deviation (RSD) for analysis of 50 ng L⁻¹ or 0.5 μg L⁻¹ of the isomer mixture was less than 8%. When the proposed method was applied to surface (river) water and tapwater samples from Gipuzkoa province (Spain) the target analytes were not detected. The method was also used to investigate the presence of the isomers in leachates from agricultural soil. A mixed solution was added to samples of two different soils and 1,3-DCP isomers were quantified in leachate obtained from the samples.     

Determination of Organochlorine Pesticides Residue in Ginseng Root by Orthogonal Array Design Soxhlet Extraction and Gas Chromatography

Organochlorine pesticides are known to enter plant products from contamination via spillage and volatilization of the residues from pesticide-treated soils or storage. A method involving four-factor-three-level orthogonal array design including extracting solvent component, particle size, solvent overflow recycle and time needed for the optimization of extracting nine organochlorine pesticides from ginseng root was developed using Soxhlet extraction followed by capillary gas chromatography–electron capture detection and mass spectrometric confirmation. The extraction conditions were optimized from the experimental data. Relationship between the bioaccumulation of benzenehexachloride isomers and their polarity is discussed based on experimental results.     

三醋酸甘油酯的气相色谱分析

本文介绍了一种快速、简便的测定高含量三醋酸甘油酯的气相色谱法。本法使用10%PEG-20M涂渍在Chromosob W上的色谱柱(2 m×3 mmi.d.),以N_2作载气(40ml/min)氢火焰离子化检测器(FID),柱温180℃,汽化温度200℃,能很好地将三醋酸甘油酯与二醋酸甘油酯分离。并选用十二醇为内标物测定了十批合成样品中的三醋酸甘油酯含量,变异系数<0.4%。     

Characterization of silicones by direct-deposition GC/FT-IR

Materials used in the manufacture of silicone breast prostheses were analyzed by supercritical fluid chromatography (SFC) and high temperature gas chromatography (GC) coupled with direct deposition FT-IR detection. The chromatographic resolution and deposition quality were found to be unsatisfactory for SFC/FT-IR; however, high temperature GC/FT-IR produced excellent results. The chromatograms and spectra obtained allowed for the identification of poly-dimethyl silicones and mono-, di-, and tri-diphenylsubstituted poly-dimethyl silicones. An automated method of baseline correction was developed that allowed functional group chromatograms due to molecules containing Si-phenyl bonds to be constructed without significant interference from Si-methyl bonds despite the fact that the Si-C stretching mode of Si-phenyl bands overlapped significantly with the strong bands due to Si-CH₃ groups.     

Solubility parameter determination of cationic surfactants by inverse GC

Summary The solubility parameters of cationic surfactants were obtained using the inverse gas chromatographic technique. The surfactants didodecyl dimethyl ammonium bromide, dioctadecyl dimethyl ammonium bromide and dodecyl pyridinium chloride were used as stationary phase and retention data of different probe solutes were measured at different temperatures. The results were analysed by the combination of Flory-Huggins and Hildebrand theories, and the solubility parameters of the surfactants were obtained in a range of temperatures between 80–120°C.     

Si(CH3)3Cl修饰的HZSM-5酸性及正己烷芳构化的催化性能研究

随着芳烃需求量的增加,低分子烃的芳构化受到广泛重视.由于HZSM-5的独特骨架结构及酸性,使其对低分子烃有良好芳构化性能~[1～3],但研究工作大多放在HZSM-5本身的硅铝比调变及加入某些金属(如Ga,Zn)来提高其芳构化性能~[4～7],而以非金属对其进行改性处理则很少见.本文以Si(CH_3)_3CI对HZSM-5进行CVD处理,并对其酸性及对正已烷芳构化能力进行了考察,研究了催化剂的结焦情况.     

Transformations of n-Hexane and Cyclohexane by Barrier Discharge Processing in Inert Gases

The conversion of n-hexane and cyclohexane by barrier discharge treatment in He, Ar, Kr, or Xe was studied. The action of a barrier discharge on n-hexane vapor primarily results in the formation of branched-chain hydrocarbons (93.48 wt %). Bicyclohexyl is the main reaction product of cyclohexane; alkyl and alkenyl substituted cyclohexanes (48.12 wt %) are also formed. Using n-hexane as an example, it was demonstrated that the energy consumption increased from 1.30 to 2.17 keV per hydrocarbon molecule converted in the following order of inert gases: He, Ar, Kr, and Xe.     

Quantitative analysis of the compounds in synthesis mixtures of 2,2-dimethyl-3-hydroxypropionaldehyde by RP-HPLC and GC

Summary RP-HPLC and GC methods are described for the determination of the compounds in synthesis mixtures of 2,2-dimethyl-3-hydroxypropionaldehyde (DHPAL). Special attention is paid to the analysis of DHPAL. Conditions for analysis are developed so that no derivatization is needed despite the equilibrium reactions typical of hydroxy aldehydes. Different solvent matrices, pH and sample concentrations are tested in sampling and analysis. Linearity of the calibration lines and precision of the methods are evaluated for all compounds. Detection limits of different compounds are calculated for both methods.     

克菌丹和灭菌丹的气相和液相色谱分析方法

采用气相色谱法和高效液相色谱法两种方法分别对克菌丹和灭菌丹进行定性定量分析。气相色谱法均以邻苯二甲酸二戊酯为内标物,色谱柱采用3%OV-101 chromosorb AW DMCS 150~177μm,1 m×3 mm玻璃柱,柱温为195℃,汽化温和检测温均为230℃,克菌丹和灭菌丹的回收率分别为99.2%~100.7%和98.8%~99.9%;方法相对标准偏差分别为0.46%和0.59%。高效液相色谱法中使用Nova-PaK C18250 mm×4.6 mm色谱柱,以V(甲醇)∶V(水)=85∶15为流动相,检测波长为225 nm。克菌丹和灭菌丹的回收率分别为99.5%~100.6%和98.9%~99.7%;方法相对标准偏差分别为0.68%和0.51%。