气相色谱-质谱法测定血浆中肌醇

建立了血浆中肌醇含量的气相色谱质谱(GC-MS)测定方法。样品采用硅烷化试剂(V(三甲基氯硅烷):V(六甲基二硅胺烷):V(N,N-二甲基甲酰胺)=1:2:8)进行衍生,净化提取后采用气相色谱质谱仪进行分析。肌醇含量在20~500μg/L范围内线性关系良好,定量限(LOQ)为5μg/kg,采用LOQ,2LOQ,4LOQ的添加水平,平行测定6次,所得平均回收率分别为89.3%,86.6%和91.0%,相对标准偏差(RSD)分别为5.1%,3.7%和4.4%。     

二羟丙酮的气相色谱分析

用衍生气相色谱法测定了二羟丙酮的酶制法体系中二羟丙酮的含量,选用六甲基二硅胺烷（ＨＭＤＳ）、六甲基二硅胺烷加三甲基氯硅烷（ＴＭＣＳ）、Ｎ,Ｏ－双（三甲基硅烷基）乙酰胺（ＢＳＡ）为衍生试剂,并对其衍生条件进行了研究。该法的回收率为９８．３１％～１０１．３１％,ＲＳＤ为２．０２％～３．５８％。     

气相色谱法分析聚酯中多元醇

用气相色谱法分析聚酯中多元醇,通常是用正丁胺降解聚酯,使生成的多元醇转变为乙酸酯或三甲基硅醚的衍生物后,再进行色谱分析。最近,Mlejnek和Cveckova提出用水合肼降解聚酯,以六甲基二硅胺烷和三氟醋酸为硅烷化试剂,将多元醇转变为硅烷化衍生物,但未给出定量结果。我们参照此法,用六甲基二硅胺烷和三甲基氯硅烷为硅烷化试剂对聚酯中多元醇进行定量分析,并将其扩大应用于聚酯聚氨酯中多元醇的分析。     

硅烷化衍生-气相色谱-质谱联用法测定烟酸

烟酸片样品用吡啶超声提取、分离后,所得上清液中的烟酸与六甲基二硅氨烷和三甲基氯硅烷进行衍生化反应,产物用正庚烷萃取。萃取液加入苯甲酸乙酯作为内标,供气相色谱-质谱分析。在气相色谱分离中用HP-5MS毛细管柱(30m×250μm,0.1μm)为固定相,在质谱测定中采用全扫描模式。烟酸标准与内标峰面积的比值与烟酸的质量浓度在1.000 g.L-1范围以内呈线性关系,检出限(3s)为4.54 mg.L-1。方法用于烟酸片剂中烟酸的测定,相对标准偏差(n=6)为1.65%~2.89%,回收率在90.1%~93.2%之间。     

阴离子交换色谱-积分脉冲安培检测法分离测定烟草料液中的山梨醇和糖

采用阴离子交换色谱-积分脉冲安培检测法分离测定了烟草料液中山梨醇、葡萄糖、果糖、蔗糖和麦芽糖,研究了山梨醇和糖在阴离子交换色谱中的保留行为。采用优化的水和氢氧化钠二元梯度淋洗条件,CarboPac PA10阴离子交换色谱柱进行分离,积分脉冲安培检测器检测一次进样测定烟草料液样品中的山梨醇、葡萄糖、果糖、蔗糖和麦芽糖。各组分在测试条件下线性关系良好,线性范围为0.005～20 mg/L,检测限为0.2～1.0 μg/L,加标回收率为95.1%~102.4%,相对标准偏差为1.2%～1.9%。     

毛细管气相色谱法测定淀粉糖浆中的糖含量

1　引　　言淀粉糖浆是由淀粉经水解、脱色和浓缩制成的 ,主要应用于食品工业。传统的分析方法是采用化学法测定其中总糖和还原糖的含量。由于采用化学法时 ,样品具有颜色或具有其它还原性物质时 ,对分析结果的准确性影响很大 ,而且 ,化学法不能测定出糖浆中各种糖的含量。本文采用二甲基亚砜为溶剂 ,环己烷为萃取剂 ,六甲基二硅氨烷和三甲基氯硅烷为衍生化试剂 ,对样品直接进行衍生化 萃取处理 ,用毛细管气相色谱法测定了淀粉糖浆中的糖含量 ,方法的相对标准偏差小于 4%。2　实验部分2 .1　仪器与试剂　ＧＣ1 2 2气相色谱仪 (上海分析仪器…     

高效阴离子交换色谱-脉冲安培检测法测定烤烟中的水溶性葡萄糖、果糖和蔗糖

用高效阴离子交换色谱-脉冲安培检测法（HPAEC-PAD）测定了烤烟中的水溶性葡萄糖、果糖和蔗糖。采用水浸取及膜过滤法处理烤烟样品,以Dionex CarboPac PA-1阴离子交换柱为色谱柱,0.2 mol/L NaOH水溶液为淋洗液进行分离测定。葡萄糖、果糖和蔗糖的含量与其峰面积的线性关系良好,回收率均在97%以上。方法简便易行,灵敏度高,重现性良好,可以实现对烟草中单糖的快速分离和测定。     

糖肟三甲基硅醚衍生物制备方法的改进——气相色谱法分离甘露糖、半乳糖和葡萄糖

将盐酸羟胺吡啶溶液与六甲基二硅胺烷混合,混合后过滤,滤液再加到标准的 D-甘露糖、D-半乳糖和 D-葡萄糖中,从而改进了糖肟三甲基硅醚衍生物常规的制备方法,解决了在常规制备方法中气相色谱法对标准己糖难分离的问题。用 OV—17固定液,气相色谱法分析了三种已糖混合物,结果三种己糖被分离,并对新的制备方法作了研究。     

气相色谱-质谱法测定奶瓶中双酚A含量

提出了气相色谱-质谱法测定奶瓶中双酚A含量的方法。取剪碎的样品经二氯甲烷溶解,甲醇提取后,所得净化液中双酚A与N,O-双(三甲基硅烷基)三氟乙酰胺-三甲基氯硅烷(99+1)溶液进行衍生化反应,产物用乙酸乙酯定容。在气相色谱分离中用DB-5MS毛细管柱为固定相,在质谱分析中采用选择离子监测模式。双酚A的质量浓度在10.0～200.0μg·L-1范围内与峰面积呈线性关系,测定下限(10S/N)为1.0mg·kg-1。方法用于奶瓶中双酚A的测定,回收率在77.5%～95.1%之间,相对标准偏差(n=6)为3.9%。     

气相色谱法测定双(2-羟乙基)对苯二甲酸酯的纯度——三甲基硅烷化技术的应用

双-(2-羟乙基)对苯二甲酸酯的纯度测定和杂质分析,由于样品中各组分的沸点和熔点都很高,直接用色谱法测定有困难。本方法是先将样品中各组分转化为相应的挥发性较强的三甲基硅烷的衍生物。以六甲基二硅氨烷和三甲基氯硅烷做硅烷化试剂,在常温下,就能很容易而且定量地制成衍生物,用气相色谱进行分析。使用了双火焰离子化鉴定器程序升温色谱仪,起始温度100℃,以12℃/分程序升温至250℃,分析一个样品不超过二十分钟。     

三甲基硅取代PPO和三苯基硅取代PPO及其气体选择透过性能

讨论了聚２，６－二甲基－１，４－苯撑氧（ＰＰＯ）与三甲基氯硅烷和三苯基氯硅烷的反应，合成了一系列取代含量不同的三甲基硅取代ＰＰＯ（ＴＭＳ－ＰＰＯ）和三苯基硅取代ＰＰＯ（ＴＰＳ－ＰＰＯ）．研究了取代基团不同和取代含量变化对聚合物的气体选择透过性能的影响，发现ＴＭＳ－ＰＰＯ的气体透过系数随三甲基硅取代量加大而增高，分离系数下降；ＴＰＳ－ＰＰＯ的气体透过系数和分离系数都随三苯基硅取代量的增加而下降，ＴＰＳ－ＰＰＯ与ＴＭＳ－ＰＰＯ的气体溶解系数相近，扩散系数差别较大．故二者气体透过系数的不同主要是由于扩散系数的差异．从化学结构与气体透过性能关系的角度来看，若在聚合物分子中引入有较小转动自由能的大基团，则有利于气体分子的扩散透过．     

三甲基硅取代PPO和三苯基硅取代PPO及其气体选择透过性能

讨论了聚２，６－二甲基－１，４－苯撑氧（ＰＰＯ）与三甲基氯硅烷和三苯基氯硅烷的反应，合成了一系列取代含量不同的三甲基硅取代ＰＰＯ（ＴＭＳ－ＰＰＯ）和三苯基硅取代ＰＰＯ（ＴＰＳ－ＰＰＯ）。研究了取代基团不同和取代含量变化对聚合物的气体选择透过性能的影响。发现ＴＭＳ－ＰＰＯ的气体透过系数随三甲基硅取代量加大而增高，分离系数下降，ＴＰＳ－ＰＰＯ的气体透过系数和分离系数都随三苯基硅取代量的增加而下降，ＴＰ     

固相萃取-气相色谱-质谱法测定酱油中3-氯-1,2-丙二醇

建立了酱油中3-氯-1,2-丙二醇(3-MCPD)残留量的同相萃取-气相色谱-质谱(GC/MS)分析方法.利用SampliQ OPT固相萃取柱净化样品,考察了乙醇、丙酮、乙醚、乙醚-正已烷(9:1,V/V)4种洗脱液对3-MCPD回收效果的影响.洗脱液在室温下经氮气吹干后用双(三甲基硅烷基)三氟乙酰胺-三甲基氯硅烷(B...     

氯硅烷的气相色谱分析

采用涂邻苯二甲酸二乙酯的气相色谱柱对用化学气相沉积法制备ＳｉＣ纤维的主要原料——氯硅烷直接进样分析,在较短的时间内即可得知每批原料的差异。实验表明,方法操作简便、快速,重复性和精密度较好,重复６次的变异系数均＜１％。可用于ＳｉＣ纤维原料的质量监测。     

Metabolomics study of cured tobacco using liquid chromatography with mass spectrometry: Method development and its application in investigating the chemical differences of tobacco from three growing regions

Cured tobacco is an important plant material. Component studies are a big challenge for its significantly diverse chemical properties and vastly different concentrations. In this work, liquid chromatography with quadrupole time‐of‐flight mass spectrometry was used to perform a metabolomics study of cured tobacco owing to its efficient separation and detection of semipolar metabolites. A solvent of methanol/water (8:2, v/v) and 30 min of ultrasound time were found to be optimal to perform extraction. 95, 92, and 93% of metabolite features had within 20% of coefficient of variation for repeatability, intraday and interday precision analysis, respectively, indicating a good stability of the method developed. 113 metabolites were identified in cured tobacco based on accurate mass, retention time, and MS/MS fragments. The developed method was applied to a metabolomics study of cured tobacco from three growing regions. Forty three metabolites were found to be contributed to the classification. It is shown that the developed method can be applied to metabolomics analysis of plant materials.     

Ultrasensitive determination of highly polar trimethyl phosphate in environmental water by molecularly imprinted polymeric fiber headspace solid‐phase microextraction

A sensitive, accurate, and cost effective method for the quantification of trimethyl phosphate, which is highly polar and volatile, in environmental water is presented. Trimethyl phosphate was headspace solid‐phase microextracted on a molecularly imprinted polymeric fiber, and then the fiber was thermally desorbed in the gas chromatograph injector, and the compound was determined. The trimethyl phosphate imprinted polymeric fiber was prepared by copolymerization in a fused silica capillary tube and obtained by removal of the wall of fused silica capillary tube. The monolithic fiber displayed good selectivity toward trimethyl phosphate among its structural analogues. It was thermally stable up to 320°C so that it can withstand the high temperature of the gas chromatograph injector for desorption. The factors influencing the performance of its headspace solid‐phase microextraction were studied. Under the optimal conditions, the method for quantification of trimethyl phosphate in environmental water was well developed. It exhibited significant linearity, the lowest limit of quantification to date, and good recoveries. Using this method, trimethyl phosphate was detected in five out of seven environmental water samples at concentration levels from 0.28 to 1.22 μg/L, illustrating the heavy pollution of trimethyl phosphate in environmental water.     

烟草中糖类物质的高效毛细管电泳-安培检测研究

将高效毛细管电泳－安培检测技术（ＨＰＣＥ－ＡＤ）用于不同烟草样品中糖类物质的测定。在 １×１０－６ｍｏｌ／Ｌ～１×１０－３ ｍｏｌ／Ｌ范围内,存在良好的线性关系,葡萄糖、果糖、蔗糖和麦牙糖的检测限均小于 ５．０ ×１０－７ｍｏｌ／Ｌ,结果令人满意。     

烷基化和硅烷化β-环糊精手性固定相的研究

合成了2,6－O－二戊基－3－O－三甲基硅烷基－β－环糊精,采用超动态法,成功地将其涂渍到弹性石英毛细管柱,经测试,柱性能稳定、寿命长、置于空气中一年半仍具有较高的柱效和手性拆分能力,利用该柱,分离了醇、酮、烯烃等一些对映体,考察了不同稀释剂配比所得固定相的立体选择性。     

Simultaneous determination of residues of thiamethoxam and its metabolite clothianidin in tobacco leaf and soil using liquid chromatography‐tandem mass spectrometry

A simple analytical method was developed to simultaneously determine thiamethoxam and its metabolite, clothianidin, in fresh tobacco leaf, soil and cured tobacco leaf using liquid chromatography with tandem mass spectrometry. Thiamethoxam and clothianidin in tobacco and soil samples were extracted with acetonitrile containing 0.1% formic acid and purified using an NH₂‐SPE column. The optimized method provided good linearity with coefficients of determination R² ≥ 0.9981. The limits of detection and quantification were between 0.006–0.12 and 0.02–0.4 mg/kg, respectively. Intra‐ and inter‐day recovery assays were used to validate the established method. The average recoveries of thiamethoxam and clothianidin in fresh tobacco leaf, soil and cured tobacco leaf were 75.04–100.47%, 75.86–86.40% and 89.83–99.39%, respectively. The intra‐ and inter‐day relative standard deviations were all <9%. The developed method was successfully applied for the analysis of thiamethoxam and clothianidin residues in actual tobacco and soil samples. The results indicated that the established method met the requirements for the analysis of trace amounts of thiamethoxam and clothianidin in fresh tobacco leaf, soil and cured tobacco leaf.