气相色谱法测定大豆中低聚糖含量

1　引　　言大豆低聚糖的提取方法为 :大豆→溶液提取→精制→浓缩→干燥→大豆低聚糖 ,其主要成分为蔗糖 (Ｃ1 2 Ｈ2 2 Ｏ1 1 )、棉籽糖 (Ｃ1 8Ｈ32 Ｏ1 6 )和水苏糖 (Ｃ2 4Ｈ42 Ｏ2 1 )。归纳起来低聚糖的分析方法主要有以下 4种 :化学分析法、纸或板层析法、高效液相色谱法和气相色谱法。以往的气相色谱法是以吡啶为溶剂的衍生化方法 ,其特点是使用吡啶为溶剂时存在着吡啶毒性较大 ,危害环境和分析工作者的健康 ,吡啶极性较大使溶剂峰拖尾造成定量不准确 ,而且要求在无水条件下操作及样品在吡啶中难溶解使操作烦琐等缺点。本文讨论了以二…     

气相色谱法测定汽油中苯含量

汽油中加入少量的苯能提高辛烷值。但使用含苯的汽油对人体健康带来损害,故需检测和控制汽油中苯含量。本文研究了汽油中苯含量测定方法。1 试验部分1.1 方法原理 含有内标物质丁酮的待测试样注入双柱系统。试样先经过装填有非极性固定相甲基硅酮的填充     

气相色谱法测定溶剂型涂料中环己酮含量

建立测定溶剂型涂料中环己酮含量的气相色谱(GC)检测方法。样品在乙酸乙酯中超声提取,以ZB–WAX毛细管柱(30 m×0.25 mm,0.25 μm)为分离色谱柱,加入十四烷作为内标物,氢火焰离子化检测器(FID)检测,内标法定量。结果表明,环己酮的质量浓度在10~250 mg/L范围内呈良好的线性关系,相关系数r=0.999 9。以阴性涂料样品为样品基质,加标平均回收率在92.5%~97.8%之间,测定结果的相对标准偏差在0.87%~1.77%(n=7)之间,方法检出限为13 mg/kg。采用该方法对15种溶剂型涂料样品进行测定,其中11种检出环己酮。该方法能使目标化合物得到有效分离,分析时间短,重复性好,灵敏度高,适用于溶剂型涂料中环己酮含量的快速测定。     

毛细管气相色谱法测定面粉中的过氧化苯甲酰

采用毛细管气相色谱法测定面粉中过氧化苯甲酰的含量。方法的线性范围为0.0-500.0μg/mL,检出限为1.0ng,RSD为0.564%-0.906%,回收率为92.7%-101.3%。该法可用于面粉质量的监测。     

毛细管气相色谱法测定药草酮异构体

药草酮异构体是许多香精香料和配套香料的重要原料。具有清新雪艾菊香韵、强烈的木香和青草香气。美国IFF(Internation Flavors ＆ Fra-grances)公司有此产品,但国内尚无生产的报道。该产品价格昂贵,又依赖进口。 药草酮化学名为3,3-二甲基环己基甲基酮,是一种异构体,分离较为困难。曾有通过薄层层析法检测药草酮异构体的报道,但只能测出主成分     

气相色谱法测定大气中的丙烯酸及其酯类化合物

用活性炭采集大气样品,OV-101(30m×0.32 mm i. d.)弹性石英毛细管柱分离丙烯酸和3种丙烯酸酯类化合物,氢火焰离子化检测器测定,建立了气相色谱法测定大气中丙烯酸及其酯类化合物的方法。该方法有较宽的线性范围,相关系数达到0.996以上,相对标准偏差为3.16％～5.83％,回收率为84.4％～95.4％,检出限为0.003～0.03 mg/m~3(采样体积为20L)。     

多维气相色谱法测定催化裂化气体组成

１引言 催化裂化气体组成测定是炼油厂中重要的分析项目之一,其组成除含有Ｃ１～Ｃ５等轻烃组分外,还含有Ｈ２、Ｏ２、Ｎ２、ＣＯ、ＣＯ２等永久性气体,常规方法是利用３台气相色谱仪,一个样品３次进样,达到全组分分离,操作繁琐且准确度差。本文介绍的多维气相色谱法测定催化裂化气体组成,一个样品只需一次进样就能达到全组分的分离检测,操作简便,且重复性好,准确度高。２实验部分２．１仪器和色谱柱 ＨＰ５８９０Ⅱ型气相色谱仪;ＨＰ３３９６Ⅱ型积分仪（美国惠普公司）。癸二腈（柱１Ａ０．６ｍ×３．２ｍｍｉ．ｄ．：柱１Ｂ …     

气相色谱法测定糖果中薄荷醇含量

薄荷醇俗称薄荷,熔点41～43℃,沸点212℃。药物上作为清凉剂、强心剂。药物中的薄荷醇可用《中国药典》制定的方法进行鉴定。糖果食品中薄荷醇的测定,目前尚未见报道。因其含量较低,且食品中常含有植物油、香精等添加剂,对于低含量薄荷醇很难测定其真实含量。 本文采用气相色谱法进行测定,用苯甲酸乙酯作为内标物,对市售国内外薄荷糖进行测定,具有较高的准确度和精密度。方法简便,重现性好。 1 试验部分 1.1 仪器与试剂 103型气相色谱仪(FID),CDMC—1E型色谱数据处理机 薄荷醇(参考标准):纯度≥99％ 1.2 气相色谱条件     

气相色谱法测定茶碱含量

茶碱(Theophylinum)化学名称为1,3-二甲基黄嘌呤,是一种用于支气管性和心脏性哮喘的常用原料药。中国药典规定的含量测定方法灵敏度低,文献报道用无水吡啶-0.05mol/L三甲基苯胺醋酸盐将茶碱衍生化后以氢火焰离子     

气相色谱法测定饮料中乙醇含量

采用样品用注射器吸附后直接经C18柱后进样，用气相色谱法测定，该方法适合多样饮料中的乙醇测定，平均回收率为98．6％，检出限为7．7mg/L。     

不同产地柴胡中微量元素的测定分析

分别采用火焰原子吸收法测定了不同产地柴胡中微量元素钙、镁、铁、铜、锌的含量。结果表明,柴胡中富含对人体有益的钙、镁、铁、铜、锌等微量元素,且不同产地柴胡中各微量元素含量有所差异,为鉴别药材的产地特征及柴胡药效功能的研究和利用提供了依据。     

Determination of Saikosaponins in Bupleuri Radix by Micellar Electrokinetic Chromatography with Experimental Design

The important pharmacological components of Bupleuri radix include saikosaponins a–d. A multivariable approach with experimental design was employed in this study to determine four saikosaponins in different species of Bupleuri radix by cyclodextrin-modified micellar electrokinetic chromatography. Compared to traditional multiple-parameter investigations, the current experimental design can shorten the time necessary for method development, and the multivariable approach can be used to evaluate the separation capability of the method and to explore the interactions of the different parameters. The significant influences of two experimental variables, including the concentration of γ-cyclodextrin and the percentage of methanol, on the responses were investigated using chromatographic resolution statistics. The optimized conditions were as follows: 25?mM of borate (pH 9.18) containing 50?mM of sodium dodecyl sulfate, 5?mM of γ-cyclodextrin, and 15% methanol (v/v) as running buffer. After the separation conditions were optimized and good resolution was acquired, solid phase extraction was performed to reduce the interference of crude extracts of Bupleurum kaoi and Bupleurum chinense DC. The simple and rapid analytical method was successfully applied, allowing for the determination of four saikosaponins and the identification of species of Bupleuri radix.     

Gas chromatographic method for the analysis of nitrochlorobenzene isomers

Summary An efficient, reproducible and rapid gas chromatographic method for the analysis of nitrochlorobenzenes has been described in this paper. The method uses FFAP as stationary phase and 3,4-dichloronitrobenzene as internal standard. The total analysis time of the method is less than 15 minutes with a coefficient of variation ranging from 0.41% to 1.19% for different levels of three isomers.     

二元环糊精体系对柴胡中柴胡皂苷a与柴胡皂苷d的毛细管电泳分离测定

以磺丁基-B-环糊精(SBE-β-CD)和β-环糊精(β-CD)组成二元手性选择体系,用毛细管电泳法对柴胡中的柴胡皂苷a及柴胡皂苷d进行分离测定.考察了缓冲液的组成和浓度、手性选择剂的组成和浓度、进样方式及样品介质等对灵敏度和分离度的影响.结果表明:采用熔融石英毛细管柱(60 cm×50 μm i.d,有效长度为53 ...     

Gas chromatographic analysis of ethylbenzene hydroperoxide

Summary A gas chromatographic method, based on the time normalization technique, is described for the analysis of ethylbenzene hydroperoxide in mixtures containing ethylbenzene, acetophenone, 1-phenylethanol, benzaldehyde and phenol. Different liquid phases were tested and the best results were obtained with tricresyl phosphate and neopentyl glycol sebacate. The influence of the support, the liquid loading and the gas velocity are discussed.     

Evaluation of traditional Chinese herbal medicine: Chaihu (Bupleuri Radix) by both high-performance liquid chromatographic and high-performance thin-layer chromatographic fingerprint and chemometric analysis

Chaihu (Bupleuri Radix), roots of Bupleurum chinense and B. scorzonerifolium, is an authentic Chinese Materia Medica in the Chinese Pharmacopoeia. Some other species such as the roots of B. falcatum, B.bicaule and B. marginatum var. stenophyllum similar to Chaihu can also be occasionally found in local raw herb markets. The quality of 33 lots of authenticated Chaihu samples vs. 31 lots of commercial samples was evaluated by both high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) and high-performance thin-layer chromatography (HPTLC) analyses of its principal bioactive components (saikosaponins). The pre-treated data acquired from both HPLC fingerprints and HPTLC fluorescent images were processed by chemometrics for similarity and pattern recognition, including Artificial Neural Networks (ANNs), k-nearest neighbor (k-NN) and an expert’s panel. It was apparent that k-NN classifier exhibited good performance with sufficient flexibility for processing HPTLC fingerprint images which were otherwise not easily dealt with by other algorithms due to the shift of R_f values and varying hue/saturation of the band colours between different TLC plates. These two chromatographic fingerprint methods can be considered complementary measure of quality control. The roots of Chaihu from different species of the genus Bupleurum could readily be distinguished from each other so that commercial samples can easily be classified. Chaihu collected from several major herbal distribution centers was found to belong to B. chinense with great variation in the content of its major saikosaponins.     

近红外光谱法快速测定柴胡提取过程中的药效成分

利用近红外光谱(NIRS)技术对柴胡提取过程中的药效成分进行快速定量分析。共收集126个柴胡提取液样品,采用紫外-可见分光光度法测定总黄酮和多糖的含量,高效液相色谱法(HPLC)测定柴胡皂苷A及柴胡皂苷D的含量,以透射模式采集提取液的近红外光谱,运用偏最小二乘法(PLS)分别建立了近红外光谱与4种药效指标参考值之间的定量校正模型,并采用不同的预处理方法、光谱波段和主因子数对模型进行优化。结果表明,总黄酮、多糖、柴胡皂苷A和柴胡皂苷D 4种定量模型的近红外预测值与参考值之间的拟合性良好,模型预测精度较高,其中预测集相关系数(R_P)均大于0.9;预测集误差均方根(RMSEP)分别为3.46μg/mL、0.743 mg/mL、1.53μg/mL、0.406μg/mL;预测集相对偏差(RSEP)分别为1.65%、8.28%、5.74%、7.52%。该研究证实了NIRS结合PLS可成功应用于监测柴胡提取液中药效成分的含量变化,且方法具有快速、准确、无损和环保的特点。     

Gas chromatographic trace analysis of underivatized nitrophenols

Summary A method for the gas chromatographic trace analysis of underivatized nitrophenols in ground-water is presented. Using a highly de-activated separation system a satisfactory precision for their quantitative GC analysis could be achieved by avoiding condensation of the solvent and by fast injection of the sample. The reproducibility of the peak areas of eleven nitrophenols in ethylacetate was <5 % RSD. Using a nitrogen-phosphorus detector detection limits were in a range from 10 to 30 pg. Within the concentration range from 0.1 to 10 ng μl⁻¹ the calibrations were linear with correlation coefficients >0.992. The approach described was applied to the analysis of nitrophenols in ground-water near a former ammunition plant, after preconcentration by continuous liquid/liquid extraction with ethylacetate. Using a GC-MS technique and retention times various nitrophenols were identified and then quantified in the μg/L-range by applying NPD.     

Recognition and identification of active components from Radix Bupleuri using human neuroblastoma SH‐SY5Y cells

The aim of the study was to screen active components of Radix Bupleuri (a traditional Chinese herb) and discover novel anti‐schizophrenic candidate drugs using human neuroblastoma SH‐SY5Y cells. SH‐SY5Y cells were used for preparation of the stationary phase in the cell membrane chromatography model. Retention components by the SH‐SY5Y/CMC model were collected and then analyzed by GC/MS under the optimized conditions in offline conditions. After investigating the suitability and reliability of the SH‐SY5Y/CMC method using amisulpride and haloperidol as standard compounds, this method was applied to screening active components from the extracts of Radix Bupleuri. Retention components of SH‐SY5Y/CMC model were saikosaponin A, saikosaponin B1, saikosaponin B2, saikosaponin C and saikosaponin D, which were identified by the GC/MS method. In vitro pharmacological trials‐MTT, saikosaponin B1, saikosaponin B2 and saikosaponin C could protect SY5Y cells. The protective effects of saikosaponin B1 and saikosaponin C were concentration dependent. Saikosaponin A and saikosaponin D inhibited cell viability at concentrations >30 µg/mL (p < 0.05). Via SH‐SY5Y/CMC method and SH‐SY5Y MTT trial, we rapidly detected target components from Radix Bupleuri, accurately identified them and determined their different effects on SH‐SY5Y cells. Saikosaponin B1, saikosaponin B2 and saikosaponin C may be anti‐schizophrenic candidate drugs. Copyright © 2015 John Wiley & Sons, Ltd.     

Gas chromatographic determination of impurities in nitromethane

Summary Impurities in commercially available nitromethane have been determined by gas-liquid chromatography using six different column packings. Besides nitromethane, 1-nitropropane, 2-nitropropane, acetonitrile, methanol, small amounts of ethanol and acetaldehyde have been detected. The presence of formaldehyde, ethyl acetate and acetone is probable. Mixtures containing comparable amounts of the four nitroalkanes could be separated on all columns, but plots of logarithms of the retention times vs. carbon number or boiling points of the nitroalkanes or column temperatures were linear only in case of columns packed with Porapak R and Q.