Determination of Theanine in Tea by High Performance Liquid Chromatography-Atmospheric Pressure Chemical Ionization Mass Spectrometry

采用高效液相色谱-大气压化学电离质谱(HPlC-APCI-MS)联用技术,建立了茶叶中茶氨酸的含量测定方法。实验采用C8柱,以甲醇-水为流动相,等度洗脱,采用正离子大气压化学电离质谱(SIM模式)进行测定,可以获得稳定的质谱信号,并采用正交实验设计对APCI-MS仪器条件进行了优化。结果表明,本文建立的HPlC-APCI-MS方法操作简便、重现性好,灵敏度较紫外检测器有很大的提高,可用于微量茶氨酸的快速测定。HPLC coupled online with atmospheric pressure chemical ionization MS technique was developed for the qualitative and quantitative determination of theanine in tea.The theanine and other compounds in the tea extract were separated on an Alltima C8 column with methanol and water (10:90 v/v) as mobile phase, with flow rate of 0.6 ml/min and APCI-MS SIM m/z 175.1 detection.In the positive APCI mode, sensitive and stable MS signal could be obtained by APCI-MS (SIM m/z 175.1) detection, and the APCI-MS conditions were also optimized by orthogonal design.The results indicated that HPLC-APCI-MS method was simple, sensitive and reliable for the determination of theanine in tea.It was important that the detection sensitivity was improved greatly by APCI-MS than UV.Eight tea samples from Fujian province were analysed using the established methods.福建省科技厅茶叶指纹图谱质量控制研究项目(2006N0043);海洋一所基本科研业务专项(GY-022008T32)资

Analysis of Alkaloids in Coptis chinensis Franch by High Performance Capillary Electrophoresis-Electrospray Ionization Time of Flight Mass Spectrometry

建立了高效毛细管电泳-电喷雾飞行时间质谱联用(HPCE-ESI-TOF/MS)快速定性分析黄连中生物碱类化合物的分析方法.使用未涂层石英毛细管,以50mmol/L乙酸铵-0.5%甲醇溶液(用氨水调至pH=7.2)作为运行缓冲液,分离电压为25kV;鞘液组成为50%甲醇-49.5%水-0.5%乙酸,鞘液流速为4μL/min;质谱选用正离子模式,碰撞电压(Fragmentor)为100V.结果表明,通过各色谱峰紫外光谱和质谱测得精确分子量结果,结合文献,对黄连中7种生物碱进行了鉴定.表明本方法简便、快速,是黄连中生物碱类化合物快速分离、鉴别的有效方法.A new method for the analysis of alkaloids in Coptis chinensis Franch was established by high performance capillary electrophoresis-electrospray ionization time of flight mass spectrometry (HPCE-ESI-TOF/MS). The real samples were separated by an uncoated capillary. 50 mmol/L ammonium acetate containing 0.5% methanol (pH=7.2) was used as the running buffer, and separation voltage was 25 kV. A coaxial sheath flow interface was used as the CE-MS interface, and a 50% methanol-49.5% water- 0.5% acetic acid mixture was used as the sheath liquid with a flow rate of 4 μL/min. The lens voltages in a positive ion mode with a collision induced dissociation (CID) voltage of 100 V were used for ESI-TOF/MS analysis. Seven alkaloids in Coptis chinensis Franch methanol extracts were separated and identified by CE-DAD and CE-ESI-TOF/MS. The coupling of HPCE separation with accurate mass measurement capability of ESI-TOF/MS provides an attractive tool for the identification of alkaloid compounds in Coptis chinensis Franch.国家自然科学基金重点项目(No.20235020);; 青岛“2004将才计划”(No.04-3-JJ-11);; 共建生物医药研发测试中心(No.LS-05-KJZX-76)资助项目

Identification of Bohai Sea crude oil based on characteristic fingerprinting by MSPD-RP-HPLC

建立渤海原油的高效液相色谱(HPlC)特征指纹图谱,为渤海原油的鉴别提供一种新方法。以氧化铝作为基质固相分散剂进行样品处理,采用HPlC法进行分析,双反相C18色谱柱串联,以乙腈-水为流动相,二元线性梯度洗脱,流速为1.0 Ml/MIn,柱温为20℃,双波长检测226 nM、254 nM,进样量10μl;采用所发展的方法对10批渤海原油样品进行分析,建立渤海原油的HPlC特征指纹图谱,结合相似度分析用于渤海原油的鉴别。该方法具有很好的精密度、重复性和稳定性,10批渤海原油特征指纹图谱有13个共有峰,结合相似度分析可以用于渤海原油样品的鉴别,说明HPlC特征指纹图谱是渤海原油鉴别的有力工具。Based on the high performance liquid chromatography(HPLC) characteristic fingerprinting,a new method for crude oil identification of Bohai Sea was developed.The sample pretreatment was done using matrix solid-phase dispersion,and Al2O3 was used as the dispersant.The chromatographic fingerprints were determined by injecting 10 L sample solution each time on two reverse phase C18 columns in series with the gradient elution solvent system composed of water and acetonitrile.The flow rate was 1.0 mL/min,the column temperature was maintained at 20℃ and the signals were acquired at 226 nm and 254 nm.The characteristic fingerprints of crude oil were established by analysis of ten representative samples derived from Bohai Sea,and identification was carried out by the similarity analysis of the characteristic fingerprints.The method was ideally suited for the fingerprinting of Bohai Sea crude oil with good precision,repeatability and stability.13 peaks were selected as the common peaks of the characteristic fingerprint and used for the similarity analysis,which could be applied to distinguish crude oil of Bohai Sea from that of other sources.The characteristic HPLC fingerprinting technique thus was a powerful tool for the identification of crude oil originated from Bohai Sea.海洋公益性行业科研专项(200705011;201005034-3);中国海监技术支撑体系项目;2008年海洋环境保护及节能减排专

Analysis of alkaloids in Coptis chinensis Franch by high performance capillary electrophoresis-electrospray ionization time of flight mass Spectrometry

A new method for the analysis of alkaloids in Coptis chinensis Franch was established by high performance capillary electrophoresis-electrospray ionization time of flight mass spectrometry (HPCE-ESI-TOF/MS). The real samples were separated by an uncoated capillary. 50 mmol/L ammonium acetate containing 0.5% methanol (pH=7.2) was used as the running buffer, and separation voltage was 25 kV. A coaxial sheath flow interface was used as the CE-MS interface, and a 50% methanol-49.5% water- 0.5% acetic acid mixture was used as the sheath liquid with a flow rate of 4 mu L/min. The lens voltages in a positive ion mode with a collision induced dissociation (CID) voltage of 100 V were used for ESI-TOF/MS analysis. Seven alkaloids in Coptis chinensis Franch methanol extracts were separated and identified by CE-DAD and CE-ESI-TOF/MS. The coupling of HPCE separation with accurate mass measurement capability of ESI-TOF/MS provides an attractive tool for the identification of alkaloid compounds in Coptis chinensis Franch