液相色谱-电喷雾离子阱质谱联用分析河豚毒素

应用C18反相色谱柱和HILIC亲水作用色谱柱,建立了河豚毒素(TTX)的液相色谱-电喷雾离子阱质谱联用分析方法。应用反相色谱法,在选择离子监测(SIM)模式下,对TTX的分析具有良好的线性响应(r=0.9992),方法检出限(S/N=3)为120pg,相对标准偏差(RSD)低于10%;应用亲水色谱法,在SIM和选择反应监测(SRM)模式下同样具有良好的线性响应(r=0.9996和r=0.9998),检出限(S/N=3)分别为15pg和3.75pg,在SIM模式下RSD低于10%,在SRM模式下RSD处于10%~20%之间。亲水作用色谱柱大大提高了方法的灵敏度,由于SIM模式具有较高的精密度,建议应用HILIC色谱柱的SIM模式定量分析TTX。     

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。     

液相色谱-电喷雾离子阱质谱分析3种兴奋剂类毒品及其代谢物

建立了3种常见兴奋剂类毒品3,4-亚甲二氧甲基苯丙胺(MDMA)、甲基苯丙胺(MA)、可卡因及其代谢物同时分离与鉴定的液相色谱-电喷雾离子阱质谱(LC-ESI-ITMS)方法。通过体外代谢方法得到大鼠肝微粒体S9组分中MDMA、MA、可卡因及代谢产物混合体系后,利用LC-ESI-ITMS联用技术对各代谢物进行分析,得到各代谢物的[M+H]+分子量信息,进一步结合多级串联质谱(LC-MSn)分析结果获得结构信息,对代谢物进行鉴定,从而快速推测代谢物结构,得到MDMA、MA、可卡因的主要代谢产物。所建立的方法用于3种常见兴奋剂类毒品及其代谢物的分析,具有快速、高效、灵敏、选择性好等特点。     

高效液相色谱-电喷雾离子阱质谱法分析6种氨基糖甙类抗生素

采用高效液相色谱-电喷雾离子阱质谱(HPLC-MSn)联用,分离和鉴定6种氨基糖甙类抗生素及其中的杂质,并探讨这6种结构相似的氨基糖甙类抗生素的质谱裂解规律。采用Agilent SB-C18(250 mm×4.6mm,5μm)色谱柱,流动相为0.05mol/L三氟乙酸溶液-甲醇(90∶10)和0.05 mol/L五氟丙酸溶液-甲醇(65∶35);在正离子检测方式下,用电喷雾离子阱质谱法对阿司米星、异帕米星、大观霉素、威替米星、奈替米星、西索米星及其杂质进行多级质谱分析。异帕米星、威替米星、奈替米星、西索米星及其杂质在二级质谱分析时,均可发生B环(脱氧链霉胺)与C环(氨基葡萄糖)之间的糖苷键断裂,生成脱去C环的碎片离子,并进一步发生A环(氨基葡萄糖)与B环之间的糖苷键断裂,生成A环或B环的碎片离子。鉴定了6种氨基糖甙类抗生素中7个杂质的结构。     

高效液相色谱-电喷雾-离子阱质谱法推定硫酸依替米星中有关物质的结构

采用高效液相色谱-电喷雾-离子阱质谱法(HPLC-ESI-IT-MSn)对硫酸依替米星中有关物质结构进行推定.采用Phenomnex Gemini NX C18色谱柱,以水-氨水-冰醋酸(96∶ 3.6∶ 0.4, V/V)-甲醇(70∶ 30, V/V)为流动相,质谱条件:电喷雾离子源(ESI),正离子检测模式;离子源温度350 ℃;雾化氮气压力275.8 kPa;干燥氮气流速10 L/min;离子阱质谱检测器,Smart扫描模式,扫描质量范围m/z 100～900.硫酸依替米星样品中共检出18种有关物质,对其中的13种物质的结构进行了推定,其余5种有关物质的结构未进行解析,只提供了分子量和二级质谱信息.     

液相色谱／电喷雾离子阱质谱测定虾中氯霉素残留

氯霉素是一种广谱抗生素，能抑制细菌蛋白质的形成。但由于其严重副作用，欧盟、美国仅允许氯霉素用于非食用动物，并规定在动物性食品中不得检出氯霉素。采用气相色谱、平面色谱、液相色谱等测定不同生物体中的氯霉素已有报道，但这些方法费时、需大量化学试剂，且灵敏度满足不了现在检测要求。采用气质联用测定氯霉素，灵敏度高，但样品前处理复杂，需衍生化。     

黄连生物碱的反相高效液相-电喷雾离子阱串联质谱的研究

采用反相高效液相-电喷雾离子阱串联质谱法对由乙醇提取的黄连生物碱进行了研究.优化出了反相高效液相色谱分离黄连生物碱的条件:流动相为V(乙腈):V(H2O)(三乙胺2 mmol/L)=30:70;柱温为30℃;流速为0.5 mL/min,并结合电喷雾串联质谱检测出了黄连生物碱中的小檗碱、药根碱、巴马汀、黄连碱以及微量的表...     

高效液相色谱-电喷雾离子阱质谱联用法测定金银花中绿原酸和咖啡酸

建立了高效液相色谱-电喷雾离子阱质谱法(HPLC-ESI-ITMSn)同时测定了金银花中绿原酸和咖啡酸活性成分的分析方法。样品用体积分数80%乙醇回流提取,用Zorbax Eclipse XDB-C18柱分离,以体积分数0.5%甲酸的乙腈-甲酸水溶液为梯度流动相,以保留时间和质荷比对分离出的组分予以定性确证,用峰面积进行定量。绿原酸和咖啡酸的线性范围均为10.0~1000.0μg/L,检出限(以信噪比为3计)均为2.0μg/L。样品的加标平均回收率为92.7%~98.7%,相对标准偏差为1.4%~2.7%。该方法适用于其它复杂体系中绿原酸和咖啡酸的分析。     

高效液相色谱/电喷雾-离子阱-飞行时间质谱分析鉴定中药虎杖中的主要化学成分

建立了快速、准确鉴别中药虎杖中化学成分的液相色谱-质谱法。采用高效液相色谱/电喷雾-离子阱-飞行时间质谱(HPLC/ESI-IT-TOF MS)对蒽醌类以及羟基二苯乙烯类对照品,包括大黄素、大黄酚、大黄素甲醚、大黄酸、芦荟大黄素和虎杖苷进行了分析,总结其多级裂解规律。建立了虎杖甲醇提取物的液相色谱分离条件及质谱检测条件,根据负离子模式下获得的各组分多级质谱数据,对比对照品碎裂特征并参考文献,对主要色谱峰进行指认,共鉴别了10个化合物,包括白藜芦醇-4′-O-葡萄糖苷、虎杖苷、大黄素-8-O-葡萄糖苷、白藜芦醇、决明松-8-O-葡萄糖苷、大黄素-1-O-葡萄糖苷、决明松-8-O-(6′-乙酰基)葡萄糖苷、大黄素甲醚-8-O-葡萄糖苷、大黄素甲醚-8-O-(6′-乙酰基)葡萄糖苷和大黄素,其中决明松-8-O-(6′-乙酰基)葡萄糖苷和大黄素甲醚-8-O-(6′-乙酰基)葡萄糖苷为虎杖中新发现的成分。研究结果表明,在中药化学成分研究工作中,采用电喷雾-离子阱-飞行时间质谱可提高中药化学成分的分析效率并有利于新化合物的发现和鉴别。     

高效液相色谱-电喷雾离子阱质谱法鉴定人尿中奥美拉唑代谢物

应用高效液相色谱－电喷雾离子阱质谱法鉴定了人口服奥美拉唑（OPZ）后0－6h内尿中的代谢物。尿中代谢物经富集后，应用高效液相色谱法分离，然后在线进行选择离子扫描（SIM）、二级碎片离子全扫描（full scan MS^2)和三级碎片离子全扫描（full scan MS^3)，进行对尿中微量的烷烃羟基化、O－脱烷烃化、硫氧化和还原以及葡萄糖醛酸化和硫酸化的9种代谢物进行了质谱解析。     

Analysis of oligonucleotides using coupled high performance liquid chromatography-electrospray mass spectrometry

Summary Improved HPLC and ESMS conditions have been established, allowing the separation and analysis of oligodesoxyribonucleotides by coupled HPLC-ESMS.     

Separation and determination of alkylglycosides by liquid chromatography with electrospray mass spectrometric detection

The separation of alkylpolyglycosides by liquid chromatography with electrospray mass spectrometric detection, using either an alkylamide or a cyanopropyl column, and acetonitrile/water mixtures as mobile phases, was developed. Using the alkylamide column and isocratic elution, the α- and β-epimers and ring isomers (pyranosides and furanosides) of the alkylmonoglycosides were resolved. The ring isomers were also resolved in a much shorter time using the cyanopropyl column with gradient elution. Using these columns, the isomers of the alkyldiglycosides and alkyltriglycosides were also partially resolved. The equilibration time was much shorter with the cyanopropyl column, which was selected to perform quantitation studies. The response factors increased more than an order of magnitude with the length of the alkyl chain, from the methyl to the decylmonoglycoside, and decrease largely for the dodecyl and tetradecylmonoglycoside. The limits of detection were of ca. 25 μM from the hexyl up to the dodecylmonoglycoside. The procedures were applied to the characterisation and determination of alkylmonoglycosides in toiletries.     

Study on the photodegradation and microbiological degradation of pirimicarb insecticide by using liquid chromatography coupled with ion-trap mass spectrometry

The intermediates of photodegradation and microbial degradation of pirimicarb insecticide were investigated by liquid chromatography coupled with ion-trap mass spectrometry (LC–IT-MS). Different intermediates were detected in the photodegradation and microbial degradation of pirimicarb. In the photodegradation of pirimicarb in aqueous solution 2-dimethylamino-5,6-dimethyl-4-hydroxypyrimidine (MW = 167), 2-methylamino-5,6-dimethylpyrimidin-4-yl-dimethylcarbamate (MW = 224) and 2-formylamino-5,6-dimethylpyrimidin-4-yl-dimethylcarbamate (MW = 252) were the main products. It was found that 2-dimethylamino-5,6-dimethyl-4-hydroxypyrimidine (MW = 167) was the major product in the microbial degradation of pirimicarb in soil.     

Characterisation of selected drugs with nitrogen-containing saturated ring structures by use of electrospray ionisation with ion-trap mass spectrometry

The electrospray ionisation–ion-trap mass spectrometry (ESI–MS ⁿ ) of selected drugs with nitrogen-containing saturated ring structures has been investigated. Sequential product-ion fragmentation experiments (MS ⁿ ) have been performed to elucidate degradation pathways for the [M+H]⁺ ions and their predominant fragment ions. These MS ⁿ experiments result in characteristic fragmentations in which functional groups are generally cleaved from the ring systems as neutral molecules such as H₂O, amines, alkenes, esters, carboxylic acids, etc. When such a nitrogen-containing drug molecule also contains a functional group, such as an ester, that on liberation as a neutral molecule has a significantly lower –H _f° value than that of the corresponding amine then the former is preferentially liberated. Furthermore, when an aromatic entity is present in these drug molecules together with the nitrogen-containing saturated ring structure fragmentation of the latter ring occurs with the former, predictably, being resistant to fragmentation. The structures of fragment ions proposed for ESI–MS ⁿ can be supported by electrospray ionisation–quadrupole time-of-flight mass spectrometry (ESI–QTOFMS). The data presented in this paper therefore provide useful information on the structure of these heterocyclic compounds which could be used to characterise unknown drug compounds isolated from natural sources, for example.     

Identification of lignans by liquid chromatography-electrospray ionization ion-trap mass spectrometry

The fragmentation pattern of 30 compounds belonging to different classes of the lignan family was studied by liquid chromatography-electrospray ionization ion-trap mass spectrometry. On the basis of the observed fragmentation patterns, identification of different types of lignans was achieved. For example, dibenzylbutyrolactone lignans showed a characteristic fragmentation pathway by the loss of 44 Da (CO(2)) from the lactone moiety, whereas dibenzylbutanediols showed a loss of 48 Da by a combined loss of formaldehyde and water from the 1,4-butanediol moiety. Lignan glycosides readily lost the sugar residue to give the parent lignan as their primary product ion. In addition, several compound-specific fragmentations were observed and used for identification of individual compounds.A versatile method for analyses of lignans was developed using LC separation on a C8 column followed by fragmentation and detection of ions produced in the ion trap.     

液相色谱-电喷雾串联质谱法测定冬青芽中的脱落酸

建立了测定植物中痕量脱落酸 (ABA) 的液相色谱-电喷雾串联质谱联用分析方法. 植物提取液先采用固相萃取 (SPE) 富集脱落酸并消除基体干扰, 然后以C18柱为固定相, V(甲醇)∶V(2 g/L甲酸水溶液)＝50∶50为流动相分离脱落酸. 电喷雾(ESI)串联质谱采用负离子模式. 选择反应监测 (SRM) 模式用于脱落酸定量, 选择的离子对是263→153, 219. 脱落酸的线性范围为0.005～10 μg/mL, 检测限 (S/N=3) 为0.003 μg/mL, 加标0.02 μg和0.05 μg的回收率分别为98.3% 和103.5%. 该方法用于冬青芽中脱落酸的分析, 结果表明所建立的SPE-LC-MS/MS方法对于分析植物中的痕量脱落酸是有效的.     

超高效液相色谱-电喷雾电离串联质谱联用法检测茶叶中阿维菌素类药物残留

建立了采用超高效液相色谱-电喷雾电离串联质谱同时检测茶叶中爱比菌素、甲胺基阿维菌素、乙酰胺基阿维菌素、伊维菌素、多拉菌素、莫西丁克残留的方法。试样经饱和氯化钠溶液浸润后,用乙腈提取,C18固相萃取小柱净化,超高效液相色谱-电喷雾串联质谱法(UPLC/ESI-MS/MS)测定。对流动相、监测离子、校正曲线等进行了优化和探讨。6种分析物在2.0～50 μg/L范围内线性关系良好,相关系数均大于0.9920。莫西丁克在5,10,20 μg/kg,其余分析物在2,5,10 μg/kg加标水平的平均回收率为61.7%～85.4%,相对标准偏差为9.37%～17.19%。该方法可靠、稳定,可满足茶叶中阿维菌素类药物残留检测与确证的需要。     

High performance liquid chromatography/ion-trap mass spectrometry for separation and simultaneous determination of ethynylestradiol, gestodene, levonorgestrel, cyproterone acetate and desogestrel

A fast and highly sensitive high performance liquid chromatographic/ion-trap mass spectrometric method (LC/MS) has been developed for simultaneous determination of ethynylestradiol (EE2), gestodene (GES), levonorgestrel (LNG), cyproterone acetate (CPA) and desogestrel (DES). Among three types of sorbents tested (C8, C18 and phenyl) from two suppliers, the best separation was achieved on reverse phase Zorbax SB-Phenyl column using aqueous methanol as a mobile phase. A linear gradient profile from 70 up to 100% (v/v) in 7th min, kept constant at 100% up to 10th min and followed by a negative gradient to 70% of methanol up to 12th min was used for elution. Applicability of electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) and influence of the mobile phase composition, its flow rate, capillary/vaporizer temperature of API source and in-source fragmentor voltage ionization are discussed. The on-column limits of quantification (10 S/N) were 300 pg of EE2, 14 pg of GES and LNG, 4 pg of CPA and 960 pg of DES per injection (1 μL) using APCI with data collection in selected ion monitoring (SIM) mode. The analytical performance of the method was evaluated using the determination of EE2, GES, LNG, CPA and DES in contraceptives and river water samples.     

Determination of pyrrolizidine alkaloids in comfrey by liquid chromatography-electrospray ionization mass spectrometry

Symphytum officinale L. (comfrey) is a medicinal plant commonly used in decoctions and aliments. Besides therapeutic bioactive compounds present in the herb, it is found to contain hepatotoxic pyrrolizidine alkaloids (PAs), such as lycopsamine and others. In the present study, PAs such as lycopsamine, echimidine and lasiocarpine were determined using electrospray liquid chromatography-mass spectrometry (LC-MS) with the method precision (relative standard deviation, RSD) <10%. Detection of lycopsamine, symviridine and their N-oxides could be confirmed with a newly developed method based on HPLC ion-trap and orbitrap MS with electrospray ionization interface. With LC-MS, quantitative analysis of lycopsamine in the botanical extract was carried out. The effect of extraction solvent was optimized by sonication and methanol: H₂O (50:50) was selected. Then a rapid method based on pressurized hot water extraction (PHWE) was employed for the extraction of lycopsamine from comfrey followed by the comparison with heating under reflux with the RSD ranging from 2.49% to 19.32%. Our results showed a higher extraction efficiency for heating under reflux compared with PHWE. It was proposed that the lower extraction efficiency for PHWE was attributable to dissolved nitrogen from air which caused the reduction in the solubility of lycopsamine in the compressed hot solvent. In this study, quantitative analysis of PAs in comfrey was demonstrated. In addition, it was found that the use of subcritical water for extractions depended on the physical properties of the dissolved solutes and their tendency to degrade under the chosen extraction conditions.     

高效液相色谱-串联质谱测定猪肉中3种β-受体激动剂残留量

建立一种同时测定猪肉中3种β-受体激动剂残留量的高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)确证分析方法。样品经β-葡萄糖醛酸酶/芳基硫酸酯酶酶解、乙酸铵缓冲液提取和MCX固相萃取柱净化,采用Agilent ZorbaxSB-C18(2.1mm×150mm,3.5μm)色谱柱,0.1%的甲酸水溶液、甲醇和乙腈作为流动相进行洗脱,高效液相色谱分离,电喷雾离子源电离,正离子多反应监测模式进行检测,内标法定量。3种药物在0.05～1μg/kg浓度范围内线性良好,相关系数r均大于0.999,0.05、0.1、0.5μg/kg3个浓度水平的添加回收率在89.7%～106.7%之间,相对标准偏差为2.4%～8.6%,3种药物的定量限均为0.05μg/kg。方法适用于猪肉中β-受体激动剂残留的确证分析。