庆大霉素的LC-MS分析

目的建立庆大霉素的LC-MS分析方法,对庆大霉素各组分进行定性和定量分析。方法利用宽pH范围XTerraLC-18(2.1mm×150mm,3μm)色谱柱,在碱性条件下,以乙腈-水(含0.2%氨水)为流动相,直接分离各组分;并采用LC-ESI-MS检测庆大霉素中各组分。结果用建立新方法,基线分离了庆大霉素中的4个主要组分和2个其他组分,并测定了4个主要组分的相对含量。结论新建立的LC-MS方法可用于该品种的定性及定量分析,该方法为庆大霉素质量控制和稳定性研究提供了可靠的分析手段。     

Identification of losartan degradates in stressed tablets by LC-MS and LC-MS/MS

Three unknown peaks were observed in the severely stressed losartan tablets (at 40 degrees C and 75% relative humidity for 3 years) analyzed by a stability indicating HPLC method. The sample solutions were subjected to liquid chromatography-tandem mass spectrometric (LC-MS/MS) analysis to obtain the chemical identities of these potential degradates. High accuracy and sensitivity of losartan and its degradates were obtained by using atmospheric pressure chemical ionization (APCI) technique in the LC-MS/MS analysis. Three trace level degradates (< or = 0.1%) were found to be the aldehyde and dimeric derivatives of losartan. The structural assignment was further confirmed by comparing the tandem mass spectra of the unknowns with those of the authentic materials of each corresponding degradate. Finally, the mechanistic pathways for the formation of the dimers are discussed.     

LC-MS analysis of serotonergic drugs

Separating drugs which are both polar and basic has long been difficult because of the limited operating pH range of conventional HPLC columns. This paper describes a liquid chromatographic method capable of being used with either diode-array or mass spectrometric detection for the identification and quantitation of 10 antidepressant and 2 antipsychotic drugs, all of which have serotonergic activity. In developing the method, the effects of varying buffers and mobile phase pH and of adding modifying agents on resolution and capacity factors were investigated. The organic buffers ammonia, glycine, and triethylamine were each used in a mobile phase made up of 32.5% buffer/67.5% methanol (v/v) at a pH of 10.0. Additionally, four different concentrations each of tetrahydrofuran and acetonitrile were added to investigate the effect of a modifying agent on resolution and retention. In general, decreasing mobile phase pH reduced retention times and decreased resolution. Adding tetrahydrofuran in place of the same amount of methanol tended to decrease retention times, and adding acetonitrile tended to slightly increase retention times. However, addition of both marginally improved resolution. This method has been used to satisfactorily analyze brain, blood, liver, urine, vitreous fluid, and stomach contents in subjects known to have used these drugs.     

LC-MS metabolomics of polar compounds

The metabolome is the complete set of small molecules coming from protein activity (anabolism and catabolism) in living systems. They have a broad range of chemical structures and physicochemical properties and therefore different analytical methodologies are necessary. Highly polar metabolites, such as sugars and most amino acids are not retained by conventional reversed-phase LC columns. Without sufficient retention, coelution may result in identification problems while the detection of compounds by MS at low concentrations may also be problematic due to ion suppression. In order to retain compounds based on their hydrophilicity, polar stationary phases and hydrophilic-interaction LC provide a complementary tool to reversed-phase LC for untargeted comprehensive metabolite fingerprinting. However, robustness of the methods is still limiting their applications. This review focuses on sample pretreatment, stationary phases, analytical methods and applications for polar compound analysis in biological matrices.     

Bioanalytical LC-MS of therapeutic oligonucleotides

Therapeutic oligonucleotides (OGNTs) are important biopharmaceutical drugs for the future, due to their ability to selectively reduce or knockout the expression of target genes. For the development of OGNTs, reliable and relatively high-throughput bioanalytical methods are required to perform the quantitative bioanalysis of OGNTs and their metabolites in biological fluids (e.g., plasma, urine and tissue). Although immunoaffinity methods, especially ELISA, are currently widely applied for this purpose, the potential of LC-MS in OGNT analysis is under investigation. Owing to its inherent ability to monitor the individual target OGNTs as well as their metabolites, LC-MS is now evolving into the method-of-choice for the bioanalysis of OGNTs. In this paper, the state-of-the-art of bioanalytical LC-MS of OGNTs and their metabolites in biological fluids is critically reviewed and its advantages and limitations highlighted. Finally, the future perspective of bioanalytical LC-MS, that is, lower detection levels and potential generic LC-MS methodology, is discussed.     

吉他霉素中各组分的LC-MS研究

目的建立吉他霉素的LC-MS分析方法,分析确定吉他霉素各组分。方法采用分析柱,以电喷雾电离、正离子检测,以确定吉他霉素各组分。结果分析确定吉他霉素实际样品中存在9个组分,即吉他霉素A1、A3、A4、A5、A6、A7、A8、A9和A13,并得出各组分的比例。结论本文为吉他霉素的质量控制提供了一种新方法。     

LC-MS Development strategies for quantitative bioanalysis

Although quantitative bioanalysis using liquid chromatography in conjunction with atmospheric pressure ionization tandem mass spectrometry (LC-MS/MS) has been in use for approximately fifteen years, new concepts and technologies are continuously being introduced to enhance the multiple steps of quantitative LC-MS/MS bioanalysis. In this review article, we have focused on concepts and technologies that have recently been introduced to achieve further improvements in biological sample collection/storage and extraction, chromatography and mass spectrometric detection. Under these major headings, a number of specific topics are presented, summarizing the most recent findings in these areas. Included among the topics discussed are: off-line plasma extraction, on-line plasma extraction, enhanced mass resolution, atmospheric pressure photoionization, high-field asymmetric waveform ion mobility spectrometry, electron capture atmospheric pressure chemical ionization, enhancing MS detection via formation of anionic and cationic adducts, chemical derivatization, ultra-performance chromatography, hydrophilic interaction chromatography, and MS-friendly ion-pair reversed-phase chromatography. In the end, we discuss potential pitfalls in LC-MS/MS bioanalysis and the means to avoid them. Such pitfalls may occur due to mass spectral interference from metabolites or prodrugs, due to the use of inappropriate calibration standard and quality control samples for analysis involving unstable drugs or metabolites, and due to the wild card phenomenon commonly known as the matrix effect.     

LC-MS法测定犬血浆中冬凌草甲素含量

目的:建立犬血浆中冬凌草甲素浓度的LC-MS测定方法,为深入研究冬凌草甲素在犬体内的药代动力学特征提供有效、可靠的检测手段。方法:采用Shim-pack VP-ODS(150 mm×2.0 mm,5μm)色谱柱,以乙腈-水(50∶50)为流动相,HPLC/电喷雾离子源质谱检测(HPLC/ESI-MS),乙酸乙酯作为萃取剂,检测犬血浆中冬凌草甲素的含量,并评价方法的稳定性和重现性。结果:本方法在0.0125~6.4μg.mL-1浓度范围内线性关系良好(R2=0.9994),定量限为0.0125μg.mL-1,平均回收率为71.18%~76.99%,日内精密度为2.4%~5.0%,日间精密度为1.2%~6.3%。室温放置30 min,样品预处理后放置24 h、-24℃贮存14 d及反复冻融3次稳定性良好。其RSD均小于15%。结论:该分析方法可行性高,重现性好,可用于研究冬凌草甲素在犬体内药代动力学特征。     

LC-MS法测定犬血浆中白屈菜红碱的浓度

目的建立测定犬血浆中白屈菜红碱浓度的LC-MS方法,研究白屈菜红碱静脉注射后体内药动学特征。方法采用Agilent C18(50 mm×2.1 mm,5μm)分析柱,以乙腈-0.75%醋酸水溶液(30∶70,V/V)为流动相,选择离子(SIR)检测方式;以白屈菜碱为内标物,测定静脉给药后犬血浆中白屈菜红碱的浓度,用3P87药动学计算程序处理数据。结果血浆中白屈菜红碱的线性范围为0.05~6.4 mg.L-1,最低定量限可达15μg.L-1,血浆中白屈菜的方法回收率在87%以上,日内和日间的RSD均<10%。结论本法准确、灵敏,可用于白屈菜红碱的血浆浓度的测定和药动学研究。     

LC/MS法测定氯硝西泮的有关物质

目的：建立氯硝西泮有关物质的LC—UV和LC—MS测定法。方法：液相色谱以C8柱为固定相;以水-甲醇（37：63）为流动相;检测波长为254nm。质谱离子源为ESI,样品采用MS和MS／MS全扫描两种模式进行分析。结果：杂质A和B分别在0．366mg&#183;L^-1～5．860mg&#183;L^-1,0．301mg&#183;L^-1～4．820mg&#183;L^-1范围内线性关系良好,相关系数分别为0．9999、0．9999,最低检测限为1．099ng、0．904ng,杂质A和B的低、中、高3种浓度的平均回收率分别为99．2％、100．2％、100．5％和100．1％、99．7％、99．6％。结论：HPLC法准确、简便,专属性强,可用于氯硝西泮有关物质的考察.     

用LC-MS法测定人血浆中顺式阿曲库铵的浓度

目的 建立高效液相色谱串联质谱方法（LC-MS）测定人血浆中顺式阿曲库铵的浓度,并应用于临床治疗药物监测。方法 采用盐酸普罗帕酮同位素内标,样品经2%甲酸水和含内标的乙腈溶液沉淀蛋白处理。HPLC色谱柱为Agilent SB-C₁₈,柱温35 ℃,流速0.3 ml/min,流动相为0.1%甲酸水和0.1%甲酸乙腈溶液,梯度洗脱。质谱检测方式为ESI正离子模式,MRM扫描,监测阿曲库铵m/z 464.6~358.4,盐酸普罗帕酮（内标）m/z 342.2~116.2。结果 人血浆中顺式阿曲库铵在该条件下分离良好,在2~500 ng/ml浓度范围内线性关系良好（r=0.996 5）,定量下限为2 ng/ml。方法日内精密度RSD<16.0%;日间精密度RSD<6.0%。平均回收率为97.63%~111.93%;血浆样品室温放置4 h,-80 ℃放置14 d,处理后室温放置24 h,稳定性良好。结论 本方法简便、准确、快速、稳定,适用于顺式阿曲库铵的血药浓度测定。     

盐酸万古霉素中杂质的LC-MS分析

目的 建立盐酸万古霉素中杂质的LC-MS分析方法.分析确定盐酸万古霉素的杂质.方法 采用分析柱,以电喷雾电离、正负离子检测,以确定盐酸万古霉素的杂质.结果 分析确定了盐酸万古霉素实际样品中的存在的3个杂质,即去氯万古霉素(monodechlorovancomycin)、去甲万古霉素(norvancomycin)和万古霉素同系物(homologous compound of vancomyein),并测定了不同厂家产品中杂质的含量.结论 本文为盐酸万古霉素的质量控制和稳定性研究提供了一种新方法.     

LC-MS/MS determination of Synercid injections

Synercid is a combination of two semisynthetic pristinamycin derivatives, quinupristin and dalfopristin in 30:70 (w/w) ratio. A rapid and specific high-performance liquid chromatography-mass spectrometry was developed for the determination of quinupristin and dalfopristin using positive electrospray tandem mass spectrometry (+ESI-MS/MS). Multiple reaction monitoring transitions at 1023.05>134.34 and 691.87>166.26 were selected for the quantitation of quinupristin and dalfopristin, respectively. The assay run cycle-time was approximately 2.0 min injection-to-injection. The assay was linear up to concentration of 4000 ng x ml(-1) quinupristin and 1920 ng x ml(-1) dalfopristin. The lowest limits of quantitation of quinupristin and dalfopristin were found to be 1000 and 480 ng x ml(-1), respectively. Quantitation was based on peak area measurement of quinupristin and dalfopristin using weighed linear regression. Linear relationships with correlation coefficients (r>0.99) were automatically computed for both constituents by MASSLYNX quantify program. The ratio of the slopes of the calibration curves of quinupristin and dalfopristin was found to be 0.425, which matches the nominal ratio composition of the antimicrobial compounds in Synercid. The %RSD ranges were 2.3-4.0% for dalfopristin and 1.3-4.2% for quinupristin, whereas the %DEV ranges were (-7.5+3.7) and (-1.2+9.1%), respectively, indicating appropriate precision and accuracy. Recoveries of 99.5-103.8% and 97.8-99.0% of quinupristin and dalfopristin, respectively, were computed from Synercid injection. The described method is recommended for rapid determination of the contents and for tracking the stability and compatibility of quinupristin and dalfopristin in Synercid injection.     

Current developments in LC-MS for pharmaceutical analysis

The current developments in liquid chromatography-mass spectrometry (LC-MS) and its applications to the analysis of pharmaceuticals are reviewed. Various mass spectrometric techniques, including electrospray and nanospray ionization, atmospheric pressure chemical ionization and photoionization and their interface with liquid chromatographic techniques are described. These include high performance liquid chromatography, capillary electrophoresis and capillary electrochromatography and the advantages and disadvantages of each technique are discussed. The applications of LC-MS to the studies of in vitro and in vivo drug metabolism, identification and characterization of impurities in pharmaceuticals, analysis of chiral impurities in drug substances and high-throughput LC-MS-MS systems for applications in the "accelerated drug discovery" process are described.     

The 27th Montreux Symposium on LC-MS

The recent Montreux Symposium on LC-MS held in 2010 provided an insight into the key areas of present achievements and future developments in LC-MS. This domain is rapidly changing from a technology- to an application-driven enterprise. New demands for advanced options are coming from (medical) biology, biotechnology, pharmaceutical and nutrition research. In particular, new diagnostic options based on -omics technologies, miniaturization and advanced data handling are rapidly being developed in relation to questions coming from personalized medicine, claim support in nutritional research, biotechnology production support and the human microbiome.     

LC-MS法测定血浆内微量非洛地平

目的 :探讨血浆内微量非洛地平的测定方法。方法 :采用反相高效液相色谱 质谱法检测兔血浆中微量非洛地平 ,以尼莫地平为内标质谱检测器。色谱柱为ItersilC1 8柱 (4 6mm× 2 5 0mm ,10 μm) ,流动相为甲醇 水 (70∶30 )及 0 1%冰醋酸 ,柱温 :4 0℃ ,流速 :1 2ml min。结果 :非洛地平的线性范围为 0 2～ 2 0 μg L(r =0 996 2 ) ;日内和日间变异系数RSD分别低于 4 5 72 %和 4 181% ;平均回收率为 87 4 %～ 91 4 %。结论 :本法灵敏度高 ,精密度和重现性好 ,测定准确 ,适用于血浆中微量非洛地平测定及人体生物利用度试验     

液质联用同时分析几种大环内酯类抗生素

目的应用液相色谱/电喷雾离子化质谱法同时分析几种大环内酯类抗生素。方法用HypersilODS2(250×4.6mm,5μm)色谱柱;以甲醇∶水∶三乙胺(68∶32∶0.1,V/V)为流动相用1mL·min-1的流速洗脱;DAD检测器检测波长230nm;柱温40℃;液相出口分流20%进入离子阱质谱,以电喷雾电离源正离子模式(MS+)进行质谱数据采集。结果得到样品液相色谱图和质谱图,并对谱图进行分析和归属。结论本方法方便、快速、灵敏、可靠,对临床药学、食品安全和生态环境等的检测方法的研究具有一定的指导意义。     

LC-MS法研究盐酸克林霉素中的有关物质

目的:建立LC-MS方法检测盐酸克林霉素中有关物质,并利用质谱对有关物质进行初步鉴定。方法:液相色谱条件:色谱柱为Diamonsil C18(250 mm×4.6 mm,5μm);流动相为乙腈-四氢呋喃-水-无水甲酸(18∶3∶79∶0.2),氨水调pH为5.45±0.02;流速:1.0 mL.min-1;检测波长:210 nm;柱温为室温;质谱条件:电喷雾电离源正离子检测;源温80℃;锥孔电压35 V。结果:检测出盐酸克林霉素原料中6个有关物质,分别为林可霉素异构体(1)、林可霉素(2)、克林霉素B(3)、7-表克林霉素(4)、克林霉素异构体(5)及去氢克林霉素(6)。除林可霉素、克林霉素B和7-表克林霉素外,其余均未被各国药典收载。结论:本文采用液质联用法,灵敏度高,分离度好,能用于盐酸克林霉素的质量控制及其代谢产物的研究。     

LC-MS法测定人血浆中尼美舒利的浓度

目的:建立以液-质联用法测定人血浆中尼美舒利浓度的方法。方法:色谱柱为Agilent Zorbox SB-Cl8,流动相为乙腈-0.1%甲酸(65∶35),流速为1.0mL·min-1,柱温为35℃,内标为缬沙坦;正离子检测模式,选择m/z309(尼美舒利,[M+H]+)和m/z436(缬沙坦,[M+H]+)进行监测。结果:尼美舒利血药浓度在5～50ng·mL-1范围内线性关系良好(r=0.9989);方法回收率为87.1%～92.9%;日内、日间RSD分别为3.1%～5.8%、6.4%～9.2%。结论:本方法灵敏、简便,结果准确可靠,重复性好,可用于尼美舒利的临床血药浓度监测和药动学研究。