高效液相色谱-串联质谱法测定纺织品中的致癌芳香胺

建立了高效液相色谱-串联质谱法(LC/MS/MS)测定纺织品中致癌芳香胺的检测方法.纺织品中的偶氮染料在柠檬酸缓冲液中用连二亚硫酸钠还原为芳香胺,用硅藻土提取还原液中的芳香胺,用乙醚洗脱,浓缩至近干后用甲醇定容.使用液相色谱-串联质谱进行测定,色谱柱为XTerra MS C18柱,流动相为甲醇和0.025 mol/L乙...     

液相色谱-串联质谱法快速测定植物源性食品中的百草枯

建立了水果、蔬菜、豆类和粮谷中百草枯残留的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法.用水提取样品中的百草枯,弱阳离子交换(WCX)固相萃取柱(SPE)净化.采用CAPCELL PAK ST色谱柱(150 mm×2.0mm).乙腈-10 mmol/L乙酸铵水溶液(用甲酸调至pH 4.0)为流动相,以电喷雾离...     

液相色谱-电喷雾离子阱串联质谱分析烟草水提取物中的尼古丁

用液相色谱-电喷雾线性离子阱串联/质谱(LC-ESI-ITMS/MS)在正离子模式下对烟草水提取物中的尼古丁进行了分析:定性分析了尼古丁MS/MS图谱中碎片的可能结构;用尼古丁标准溶液对质谱检测条件进行优化后,在SRM扫描模式下对尼古丁进行定量分析。最低检出限(LOD)可达0.21μg/L;回收率为99%-105%。测试3个不同浓度样品得到的RSD为0.64%-0.72%。实验选用高效的短色谱柱达到了快速定量的目的,适用于对大量样品的分析。     

气相色谱-质谱法测定蔬菜与水果中11种三唑类农药残留

建立了蔬菜和水果中11种三唑类农药残留的气相色谱-质谱(GC - MS)测定方法.样品用乙腈均质提取,经石墨化炭黑/氨基复合柱净化,乙腈-甲苯(3:1)洗脱.洗脱液经浓缩、溶剂交换后定容,采用气相色谱-质谱的选择离子监测方式( GC - MSD/SIM)进行测定,内标法定量.方法的线性范围为0.05～5 ng,相关系数...     

硅烷化GC/MS法同时测定卷烟中的糖、1,2-丙二醇和甘油

建立了硅烷化衍生化法结合气相色谱/质谱(GC/MS)法同时测定卷烟中1,2-丙二醇、甘油和糖类物质含量的分析方法。样品以N,N-二甲基甲酰胺(DMF)和N,O-双(三甲基硅烷基)三氟乙酰胺(BSTFA)为提取溶剂和衍生化试剂,于70℃衍生化反应30 min,采用DB-5MS色谱柱(60 m×0.25 mm×0.25μm),用GC/MS分析测定1,2-丙二醇,甘油、果糖、葡萄糖和蔗糖的含量。方法线性关系良好,检出限为0.04~2.85 mg/g,定量限为0.13~9.51 mg/g,平均加标回收率为90.3%~114.4%,相对标准偏差小于9.1%。方法适合于卷烟样品中1,2-丙二醇、甘油和糖类物质的同时测定。     

高效液相色谱-串联质谱法测定食品中的矮壮素与缩节胺残留

建立了食品中矮壮素和缩节胺2种植物生长调节剂的高效液相色谱-电喷雾电离串联质谱(HPLC-ESI MS/MS)分析方法.样品经甲醇-水(1:1,体积比)提取后,采用Strata-X-C萃取小柱净化,再经Agilent ZORBAX RX-SIL(1.8μm,3.0 mm×100 mm)色谱柱分离,以乙腈和10 mmol...     

UPLC-MS/MS同时检测染发剂中三种二氨基酚类物质

建立了超高效液相色谱-串联质谱( UPLC-MS/MS)同时检测染发剂中三种二氨基酚类物质(2,4-二氨基苯酚盐酸盐、2,4-二氨基苯甲醚盐酸盐、2,3-二氨基苯酚)含量的方法.样品经0.1％甲酸水溶液提取,正己烷净化后,用Waters ACQUITY BEH Shield RP18色谱柱进行分离,流动相为甲醇和5 m...     

液相色谱-串联质谱法同时测定水产品中孔雀石绿、 结晶紫以及它们的隐色代谢物残留

采用液相色谱-串联质谱法(LC-MS/MS)同时测定水产品中的孔雀石绿、结晶紫以及它们的隐色代谢物残留。匀质后的水产品样品用乙腈和乙酸铵缓冲液提取。合并提取液,用二氯甲烷反提取,经中性氧化铝柱和PRS柱固相萃取净化。采用ZORBAX SB-C18色谱柱,并以0.5 mmol/L乙酸铵-乙腈(体积比为10∶90)混合溶液为流动相,无需使用氧化铅柱在线氧化,色谱分离后直接进入串联质谱检测器检测。采用电喷雾离子源,正离子多反应监测(MRM)模式检测。方法的检测限（S/N=3）可达0.5 ng/g,平均加标回收率为77.6%～98.1%,相对标准偏差均小于8.2%。大量实际水产品样品的检测结果表明,此方法适合于对水产品中孔雀石绿、结晶紫以及它们的隐色代谢物的残留检测。     

超高效液相色谱-串联质谱法同时快速测定卷烟烟丝中的6种生物碱

建立了超高效液相色谱-串联质谱( UPLC - MS/MS)同时快速测定烟草中6种生物碱的方法.对样品前处理条件和仪器分离条件进行了优化,样品经去离子水超声提取后,于UPLC BEH C18色谱柱上分离,在多反应监测模式下采用同位素内标法定量以排除基质效应.结果表明,6种生物碱的线性范围为0.1～8 000 μg/L,...     

液相色谱-串联质谱法测定水稻中生长素及其氨基酸结合物

建立了同时测定水稻中吲哚-3-丁酸(IBA)、吲哚-3-乙酸(IAA)及其7种氨基酸结合物的液相色谱-串联质谱( HPLC - MS/MS)检测方法.样品在4℃下于80％甲醇中浸提12 h后,经混合阴离子交换反相固相萃取(MAX)净化,以5 mmol/L的甲酸铵溶液和甲醇为流动相,在C18柱上进行液相色谱分离,电喷雾正...     

氯丙嗪在大鼠体内的代谢研究

采用气相色谱-质谱法(GC-MS)检测大鼠尿液中的氯丙嗪及其代谢产物,并对其进行质谱解析,推测氯丙嗪在大鼠体内的代谢途径.通过对Wistar大鼠进行灌胃服用药物后收集24 h内尿样,经固相萃取(SPE)净化提取后,采用GC-MS(EI,PCI)检测.对比空白尿液与阳性尿液萃取液的质谱图,并根据质谱裂解规律鉴定其结构.实...     

荔枝中抑霉唑和嘧霉胺残留量的超高效液相色谱-串联质谱法同时测定

建立了超高效液相色谱-串联质谱法同时测定荔枝中抑霉唑和嘧霉胺的方法,对提取试剂、流动相、质谱条件进行了研究,并对抑霉唑和嘧霉胺可能的断裂机理进行了推测。待测样品直接用乙腈提取,采用电喷雾离子源(ESI)、多反应监测正离子模式扫描,外标法定量。抑霉唑、嘧霉胺的质量浓度在1.00～20.0μg/L范围内与峰面积呈良好线性,方法的检出限为0.005mg/kg;添加水平为0.005、0.010、0.020mg/kg时抑霉唑和嘧霉胺的平均回收率分别为91%～96%和83%～90%,相对标准偏差分别为6.5%～8.4%和9.5%～11.1%。该方法快速、简便、准确,可用于荔枝中抑霉唑和嘧霉胺残留量的定性与定量检测。     

Adsorption of water vapour from humid air in carbon molecular sieves: carbosieve S-III and carboxens 569, 1000 and 1001

The adsorption of water vapour in carbon molecular sieves (CMS) used to determine volatile organic compounds (VOCs) in air was investigated. The CMS mass in the trap was found not to affect the mass of retained water under conditions of incomplete saturation of the adsorbent bed with water. Thus, the restrictions commonly imposed on the CMS mass are not necessary. The usefulness of four different CMSs to sample large volumes of humid air was estimated. Carboxen 1000 exhibited the best performance. To assess the magnitude of CMS mass in the trap in dependence on the volume, the relative humidity and the temperature of the sample, the use of a novel parameter, called the water vapour interference factor, was suggested.     

乳制品中那他霉素的超高效液相色谱-串联质谱法快速测定

建立了超高效液相色谱-电喷雾串联质谱(UPLC-MS/MS)快速检测乳制品中那他霉素的方法。样品用甲醇提取,以甲醇-水为流动相经反相色谱柱分离后,采用多反应监测(MRM)负离子模式检测,定性离子对为m/z663.6/421.1和m/z663.6/439.1,其中m/z663.6/421.1用于外标法定量。空白样品及其加标实验结果表明:特征离子相对强度比值稳定,无基质干扰,结合保留时间可实现准确的定性定量;方法定量下限为50.0μg/kg;乳制品加标量为50~500μg/kg时,平均回收率为80%~91%,相对标准偏差(n=6)为2.7%~5.2%。方法简单、灵敏、稳定,可满足乳制品中那他霉素的快速检测与确证需要。     

Electrospray ionization mass spectrometry from discrete nanoliter‐sized sample volumes

We describe a method for nanoelectrospray ionization mass spectrometry (nESI‐MS) of very small sample volumes. Nanoliter‐sized sample droplets were taken up by suction into a nanoelectrospray needle from a silicon microchip prior to ESI. To avoid a rapid evaporation of the small sample volumes, all manipulation steps were performed under a cover of fluorocarbon liquid. Sample volumes down to 1.5 nL were successfully analyzed, and an absolute limit of detection of 105 attomole of insulin (chain B, oxidized) was obtained. The open access to the sample droplets on the silicon chip provides the possibility to add reagents to the sample droplets and perform chemical reactions under an extended period of time. This was demonstrated in an example where we performed a tryptic digestion of cytochrome C in a nanoliter‐sized sample volume for 2.5 h, followed by monitoring the outcome of the reaction with nESI‐MS. The technology was also utilized for tandem mass spectrometry (MS/MS) sequencing analysis of a 2 nL solution of angiotensin I. Copyright © 2010 John Wiley & Sons, Ltd.     

Solid phase microextraction with matrix assisted laser desorption/ionization introduction to mass spectrometry and ion mobility spectrometry

Solid phase microextraction (SPME) with matrix assisted laser desorption/ionization (MALDI) introduction was coupled to mass spectrometry and ion mobility spectrometry. Nicotine and myoglobin in matrix 2,5-dihydroxybenzonic acid (DHB), enkephalin and substance P in alpha-cyano-4-hydroxy cinnaminic acid were investigated as the target compounds. The tip of an optical fiber was silanized for extraction of the analytes of interest from solution. The optical fiber thus served as the sample extraction surface, the support for the sample plus matrix, and the optical pipe to transfer the laser energy from the laser to the sample. The MALDI worked under atmospheric pressure, and both an ion mobility spectrometer and a quadrupole/time-of-flight mass spectrometer were used for the detection of the SPME/MALDI signal. The spectra obtained demonstrate the feasibility of the SPME with MALDI introduction to mass spectrometry instrumentation.     

Effects of experimental sample mass on the calorimetric study of thermoset resins

It is known that experimental parameters may affect peak characteristics in DSC studies. Kinetic parameters calculated from isothermal and dynamic runs, can also be affected by the choice of experimental conditions.The sample mass can affect the determination of reaction parameters because of the heat transport and the self-insulating properties of large masses.In the curing process of thermoset resins like unsaturated polyester crosslinked by styrene, the exothermal heat results from the reaction advance but it also produces an autocatalytic process that induces an increase in the reaction rate. The sample mass, in this kind of experiments, can influence the determination of reaction parameters not only through the effect of heat transport or thermal lag on the calorimetric results but also through the action that the sample mass exerts on the exothermal heat, and consequently, on the autocatalytic process.In this paper we intend to present the results obtained in the study of the curing kinetics of thermoset resins by DSC technique using different sample masses. We will point out that the reaction heat determined by dynamic measurement was found to be independent of the sample mass. We have obtained differences in the kinetic parameters like the reaction order, activation energy and preexponential factor when the sample mass was changed.The research reported was supported by CICYT under Grant no. MAT89-377-C02-02.     

Solid—liquid phase diagrams of mixtures containing substituted phenols and amine mixtures

The thermal decomposition of CaCO₃ was studied under high vacuum by means of both TG and the more recently developed constant decomposition rate thermal analysis (CRTA) which allows the monitoring of both reaction rate and the residual pressure over the sample. The reliability of the kinetic results seems to be much higher with the latter technique which actually allows the reduction of the reaction rate and therefore the heat and mass transfer effects over a broad range of sample size. For instance, it was necessary, by conventional TG started under a vacuum of 2 10^?6 torr with a heating rate of 0.5 K min^?1, to lower the amount of sample to 2 mg in order to obtain the same activation energy as that calculated from CRTA with various samples weighing up to 50 mg. The TG experimental conditions quoted above (and which are upper limits of mass and heating rate) are beyond the limit of sensitivity of most available conventional TG equipment.     

不同色浆质量分数的水性聚氨酯涂料对聚氯乙烯表皮低温爆破性能的影响

本文制备了一系列不同色浆质量分数的水性聚氨酯涂料,并将其喷涂在汽车仪表板聚氯乙烯(PVC)表皮的背面形成复合材料。 用旋转流变仪表征了涂料的粘度以评价其喷涂性能;用差示扫描量热仪表征了材料的玻璃化转变温度(T_g);利用万能材料试验机表征了材料在-30 ℃条件下的拉伸性能及抗撕裂性能;用动态热机械分析仪表征了材料的损耗比随温度的变化。 结果表明:不同色浆质量分数的涂料都能喷涂,含有涂层材料PVC表皮在-30 ℃低温爆破性能与涂层材料的T_g、低温拉伸性能、抗撕裂性能的关系并不大,而与涂层材料的阻尼性能直接相关。 材料的阻尼性能越好,其低温爆破性能越好。