Stress degradation study and structure characterization of oxidation degradation product of dexlansoprazole using liquid chromatography-mass spectrometry/time of flight,liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance

The present study deals with the forced degradation behavior of dexlansoprazole under International Conference on Harmonisation (ICH) prescribed stress conditions. The drug was found to be more labile under acid, base, neutral, oxidative hydrolysis and thermal stress, while it was moderately stable under photolytic conditions. The known and unknown degradation products were separated on a C-18 column using a stability-indicating method. Liquid chromatography-mass spectrometry (LC-MS) analysis was performed for all the degradation studies. Isolation and structure characterization of oxidation degradation products were executed using sophisticated tools, viz. preparative high performance liquid chromatography (HPLC), liquid chromatography-mass spectrometry/time of flight (LC-MS/TOF), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and nuclear magnetic resonance (NMR). This study demonstrates an ample methodology of degradation studies and structure elucidation of unknown degradation products of dexlansoprazole, which helps in the development and stability study of active pharmaceutical ingredients and formulated products.     

应用超高效液相色谱-四极杆-飞行时间质谱法建立谷物中18种真菌毒素非靶向筛查数据库及确证方法

建立了基于超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF/MS)的18种真菌毒素非靶向筛查方法。真菌毒素标准物质用HSS T3色谱柱进行色谱分离后在UPLC-Q-TOF/MS MS^E模式下分别用正、负离子模式采集,获取MS和MS/MS的信息,记录对应保留时间、加合物离子、碎片离子精确质量数等信息,设置保留时间偏移为0.3 min,加合物离子和碎片离子的精确质量匹配容差为5×10^-6,在UNIFI中建立18种真菌毒素的数据库。在稻谷、小麦基质中,以筛查检出限(SDL)作为主要参数对筛查方法进行了验证。18种真菌毒素分为有最大限量和无最大限量两种类型,结果有最大限量的真菌毒素均能在其限量水平被准确筛查,无最大限量的真菌毒素其SDL的范围为2~800μg/kg。基质效应考察表明,稻谷中有14种真菌毒素有中等基质效应,小麦中有11种真菌毒素有中等基质效应。样品经乙腈提取后用QuEChERS萃取盐包和HLB净化柱净化,用建立的方法对25批稻谷、小麦进行筛查,结果2批稻谷中检出4种真菌毒素,2批小麦中检出2种真菌毒素。该方法能准确筛查SDL水平以上的真菌毒素,具有高通量、简便、快捷、准确等特点,可实现无标准品情况下对稻谷、小麦中多种真菌毒素的定性筛查。     

超高效液相色谱-四极杆飞行时间质谱法非靶向筛查西红柿中三唑类杀菌剂

建立了超高效液相色谱-四极杆飞行时间质谱非靶向快速筛查西红柿中三唑类杀菌剂的方法。样品用乙腈提取、QuEChERS净化、BEH C₁₈(100 mm×2.1 mm, 1.7μm)色谱柱分离,以乙腈和水(均含0.1%(v/v)甲酸)为流动相进行梯度洗脱,采用四极杆飞行时间质谱仪进行检测。质谱离子源为电喷雾电离源,采集方式为正离子数据非依赖分析MS^E扫描模式。将19种三唑类杀菌剂按化学结构的不同分为8类。首先通过对8类典型三唑类杀菌剂中代表性的8种标准品的二级质谱图进行分析,总结出三唑类杀菌剂经碰撞诱导解离后产生的特征碎片离子和特征中性碎片丢失的质谱裂解规律,然后再利用另外11种三唑类杀菌剂标准品进行验证,并用于16份北京市售西红柿的非靶向筛查,在1份样品中筛查出烯唑醇。该方法快速、简便、准确率高,可为食品中三唑类杀菌剂残留的筛查提供参考。     

超高效液相色谱-四极杆-飞行时间质谱法快速测定水产品中微囊藻毒素和节球藻毒素

通过超声提取、固相萃取纯化、超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF-MS)联用技术快速测定水产品中的微囊藻毒素-RR、-YR、-LR和节球藻毒素.分别采用选择离子监测质荷比(m/z)为519.84、1045.66、995.67、825.54分子离子峰进行定量分析.该法检出限为5.0～10.0μg/kg,在浓度0.02～5mg/kg的范围内,峰面积与样品浓度呈良好线性关系;4种藻毒素的回收率为76.2％～93.7％,相对标准偏差为2.0％～7.1％.采用上述方法对45个太湖水产品样品进行测定,发现有少量水产品中存在藻毒素污染,其中微囊藻毒素-RR最高含量为15.2μg/kg,微囊藻毒素-LR最高含量为0.84μg/kg,MC-YR、节球藻毒素均未检出.此方法可作为监测水产品体内蓄积藻毒素的分析方法.     

超高效液相色谱-四极杆飞行时间质谱法非靶向快速筛查进口粮谷中未知的农药残留

利用快速提取农药(fast pesticide extraction,FaPEx)方法前处理样品,并结合超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF)技术建立了非靶向快速筛查进口粮谷中未知的多种农药残留方法。采用1%(v/v)醋酸乙腈溶液提取粮谷中未知的农药残留,FaPEx固相萃取柱净化、浓缩,UPLC-Q-TOF检测。利用目标化合物特征离子的精确质量数、同位素匹配、二级碎片信息和保留时间进行数据库匹配,筛查可疑未知农药。结果表明,该方法无需对照标准品即可快速筛查进口粮谷中的农药残留,能够应用于进口粮谷样品的实际筛查。该方法快速、准确、分析通量高,可以为进口粮谷中农药残留的快速筛查和质量控制提供重要的方法依据。     

超高效液相色谱-四极杆飞行时间质谱法测定克氏螯虾中39种兽药残留

建立了超高效液相色谱-四极杆飞行时间质谱（UHPLC-Q-TOF-MS）快速筛查克氏螯虾中39种兽药残留的分析方法。样品经酸化乙腈提取,增强型脂质去除净化剂（EMR-Lipid）结合石墨化多壁碳纳米管（GMWNTs）净化,采用UHPLC-Q-TOF-MS分析检测。通过比对待测物准分子离子的精确质量数、同位素丰度比、保留时间等特征信息进行定性初筛,通过二级谱图谱库检索比对进行确证,通过一级提取离子色谱图峰面积进行定量分析。39种化合物在各自的浓度范围内均呈良好的线性关系,线性相关系数均大于0.99,定量限为3~15 μg/kg,添加回收率为62.4%~105.8%,相对标准偏差（RSD）为2.5%~13.5%,方法简便、快速、准确,可应用于克氏螯虾中喹诺酮类、磺胺类、三苯甲烷类39种药物残留的快速筛查定量。     

超高效液相色谱-四极杆-飞行时间质谱法快速筛查农药制剂中非法添加的杀虫剂

建立了农药制剂中48种非法添加杀虫剂的超高效液相色谱-四极杆-飞行时间质谱（UPLC-Q-TOF MS）快速筛查方法。可湿性粉剂、乳油和悬浮剂3种剂型的农药制剂样品经甲醇溶解、提取后,采用UPLC-Q-TOF MS检测,48种杀虫剂在0.5～20 mg/L范围内线性关系良好,线性相关系数（R²）大于0.99。48种农药的定量限为0.05～0.4 mg/kg,检出限为0.01～0.2 mg/kg,低、中、高3个加标水平下的平均回收率为86.3%～101.5%,相对标准偏差为1.7%～4.0%。该方法快速、准确,可用于农药制剂中多种杀虫剂的快速筛查。     

An analytical method for cyclosporine using liquid chromatography–mass spectrometry

A liquid chromatographic mass spectrometric (LC‐MS) assay has been developed for cyclosporine A (CyA) in rat plasma using amiodarone as internal standard (IS). Rat plasma (100 µL) containing drug and IS were extracted using liquid–liquid extraction with 4 mL of 95:5 ether:methanol. After evaporation of the organic layer the residue was reconstituted with 500 µL of water. Then the aqueous layer was transferred to LC‐MS sample vials. A 10 µL volume was injected. The analysis was performed on a C₈ column 3.5 µm (2.1 × 50 mm) heated to 60°C with a mobile phase consisting of acetonitrile:methanol:0.2% NH₄OH (60:20:20) at an isocratic flow‐rate of 0.2 mL/min. The ions used for quantitation of CyA and IS were m/z 1202.8 and 645.9, with retention times of 3.35 and 4.72 min, respectively. Linear relationships (r² > 0.99) were achieved between plasma or blood concentration and peak height ratios (drug:IS) over the concentration range 50–5000 ng/mL. The CV% and mean error were <19%. Based on validation data, the lower limit of quantification for the assay was 50 ng/mL. The reported assay method displayed high measures of linearity, sensitivity, reliability and precision, allowing its applicability in pharmacokinetic studies in rat. Copyright © 2009 John Wiley & Sons, Ltd.     

高效液相色谱-四极杆飞行时间质谱法同时检测豆芽中的3种外源植物激素残留

建立了高效液相色谱-四极杆飞行时间质谱同时测定豆芽中6-苄基腺嘌呤、4-氯苯氧乙酸、赤霉素等3种外源植物激素残留的方法。采用QuEChERS前处理技术,豆芽样品以酸化乙醇-乙腈溶液（1%（v/v,下同）乙酸+50%乙醇+49%乙腈）提取目标化合物,并经乙腈再提取后合并提取液;经硅藻土分散固相净化、正己烷去脂后氮吹至近干;用2.0 mL 50%（v/v）甲醇水溶液定容,过滤膜后上机检测。液相色谱以甲醇-水（含0.1%（v/v）的甲酸）作为流动相梯度洗脱,C₁₈色谱柱分离;质谱采用高分辨质谱、负离子模式,以精确质量数和二级特征离子定性,以准分子离子峰面积定量。结果表明3种目标化合物的定量限为5.0~10.0 μg/kg,线性范围为1~200 μg/L;平均添加回收率为79.1%~96.1%,相对标准偏差为5.7%~10.4%。本方法具有操作简单、快捷、灵敏度高等优点,适用于市场上豆芽质量的快速筛查检测。     

Development of stability-indicating assay method and liquid chromatography-quadrupole-time-of-flight mass spectrometry-based structural characterization of the forced degradation products of alpelisib

The US Food and Drug Administration and the European Medicines Agency approved alpelisib in 2019 for the treatment of metastatic breast cancer. A thorough literature review revealed that a stability-indicating analytical method (SIAM) is not available for the quantification of alpelisib and its degradation products (DPs). In this study, per the comprehensive stress study recommended by the International Council for Harmonisation (ICH), alpelisib was exposed to hydrolysis, oxidation, photolysis, and thermal stress. Degradation of the drug was observed under hydrolysis, oxidative, and photolysis conditions, whereas the drug was stable under thermal stress condition. We developed a SIAM for the separation of alpelisib and its major DPs that were formed under different stress conditions. The validation of the developed method was performed per ICH Q2(R1) guidelines. Five DPs were identified and characterized. Structure elucidation of all DPs was performed with the modern characterization tool of liquid chromatography-quadrupole time-of-flight mass spectrometer (LC-Q-TOF-MS/MS). The degradation pathway of the drug and its mechanisms were outlined, and in silico toxicity prediction was performed using the ProTox-II tool.     

Identification and quality evaluation of different processed products of Aconitum carmichaelii by ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry and ultra-high-performance liquid chromatography-tandem mass spectrometry

Aconitum carmichaelii is widely used to treat chronic and intractable diseases due to its remarkable curative effect, but it is also a highly toxic herb with severe cardiac and neurotoxicity. It has been combined with honey for thousands of years to reduce toxicity and enhance efficacy, but there has been no study on the chemical constituent changes in the honey-processing so far. In this study, the chemical constituents of A. carmichaelii before and after honey-processing were characterized by ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry. The results showed that a total of 118 compounds were identified, of which six compounds disappeared and five compounds were newly produced after honey-processing, and the cleavage pathway of main components was elucidated. At the same time, 25 compounds were found to have significant effects on different products, among which four compounds with the biggest difference were selected for quantitative analysis by ultra-high-performance liquid chromatography-tandem mass spectrometry. This study not only explained the chemical differences between the different products, but also helped to control the quality of the honey-processed products more effectively, and laid a foundation for further elucidating the mechanism of chemical constituent change during the honey-processing of A. carmichaelii.     

超高效液相色谱-四极杆-飞行时间质谱法测定防脱发化妆品中19种非法添加化学成分

建立了超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF-MS)法,结合高分辨质谱数据库,用于快速筛查及定量分析防脱发化妆品中19种非法添加化学成分.实验比较了提取溶剂的影响,优化了色谱条件和质谱条件.采用ACQUITY UPLC BEH C18色谱柱(100 mm×2.1 mm,1.7μm)进行色谱分离,以乙...     

Interpretation of high-throughput liquid chromatography mass spectrometry data for quality control analysis and analytical method development

An approach to rapidly process and interpret high-throughput liquid chromatography mass spectrometry data is presented. This approach applies an in-house developed computer application to process LC-MS report files containing spectral and chromatographic data from four different detectors (i.e. electrospray positive ionization, electrospray negative ionization mass spectrometry, UV absorption, and evaporative light scattering detection). Properties characteristic of detection and chromatographic retention are extracted and populated into a database. Approaches to applying this analytical information database for quality control analysis of ca. 400,000 samples are presented. Compound quality assessment methods employing average purity and detection data fields are compared to methods employing multiple quality control criteria (e.g. detection, purity, retention, and signal to noise). Structural similarity searches were applied with the analytical information database to identify compounds that may be undetectable by electrospray mass spectrometry. In addition, an approach to applying the database to aid in the selection of analytical detection and chromatography conditions for rapid analytical method development is also discussed.     

Development of an analytical reversed-phase high-performance liquid chromatography-electrospray ionization mass spectrometry method for characterization of recombinant antibodies

Analytical characterization of monoclonal antibodies has been hindered by the lack of appropriate chromatographic methods to be used in conjunction with high-resolution MS. Current methodologies for standard RP-HPLC are incompatible with antibodies due to irreproducibility, low recovery, short column lifetimes, and poor resolution of degradation products. An analytical RP-HPLC-MS method was developed for monitoring and characterizing intact IgG1antibodies. Key parameters required for improved chromatographic resolution included long alkyl chains of the stationary phase (Zorbax SB300 C8), column temperatures elevated to 65-70 degrees C and combination of trifluoroacetic acid and heptafluorobutyric acid ion-pairing agents. RP chromatographic separation of degradation species and C-terminal lysine variants along with the characterization of glycosylation profile by mass spectrometry demonstrates the capability of this method for whole antibody analysis.     

Identification of metabolites of Ginkgolide B in vivo and in vitro using ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry

Ginkgolide B is a dietary diterpene with multiple pharmacological activities. However, current research on ginkgolide B is not comprehensive. The current study analyzed the metabolic profile of ginkgolide B in vivo and in vitro using ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry. To detect and identify the different metabolites in ginkgolide B, a novel data processing method was used as an assistant tool. A total of 53 different metabolites of ginkgolide B (38 phase I metabolites and 15 phase II metabolites) were detected relative to blank samples. The biotransformation route of ginkgolide B was identified as oxidation, dehydroxylation, hydrogenation, decarbonylation, demethylation, sulfate conjugation, glucose conjugation, methylation, and acetylation. The current study demonstrated a method for rapidly detecting and identifying metabolites and provided useful information to further characterize the pharmacology and mechanism of ginkgolide B. A method for the analysis of other diterpene metabolic components in vivo and in vitro was also established.     

Selective separation and characterization of the stress degradation products of ondansetron hydrochloride by liquid chromatography with quadrupole time‐of‐flight mass spectrometry

Ondansetron hydrochloride was subjected to forced degradation studies under various conditions of hydrolysis (acidic, basic, and neutral), oxidation, photolysis, and thermal as prescribed by International Conference on Harmonisation guideline Q1A (R2). A simple, selective, precise, and accurate high‐performance liquid chromatography method was developed on a Waters Xterra C₁₈ (150 × 4.6 mm id, 3.5 μm) column using 10 mM ammonium formate (pH 3.0)/methanol as a mobile phase in gradient elution mode at a flow rate of 0.6 mL/min. The method was extended to liquid chromatography quadrupole time‐of‐flight tandem mass spectrometry for identification and structural characterization of stress degradation products of ondansetron. The drug showed significant degradation in base hydrolytic and photolytic stress conditions in the liquid state, while it was found to be stable in neutral, acidic, thermal, and oxidative stress conditions. A total of five degradation products were characterized and most probable mechanisms for the formation of degradation products have been proposed on the basis of a comparison of the fragmentation of the [M + H]⁺ ions of the drug and its degradation products. Finally, the developed method was validated in terms of specificity, linearity, accuracy, precision, and robustness as per International Conference on Harmonisation guideline Q2 (R1).     

Identification and quantification of cucurbitacin in watermelon frost using molecular networking integrated with ultra-high-performance liquid chromatography-tandem mass spectrometry

Watermelon frost, a traditional Chinese medicine produced using watermelon and Glauber's salt, has been widely used for the therapy of oral and throat disorders. Watermelon contains various phytochemical compounds including cucurbitacins and their glycoside derivatives, which have attracted considerable attention because of their medicinal values. However, whether the composition of cucurbitacins existed in watermelon frost was rarely reported. In this study, three cucurbitacins including cucurbitacin B, isocucurbitacin B, and cucurbitacin E were found from watermelon frost extract assisted by ultra-high-performance liquid chromatography-tandem mass spectrometry and molecular networking guided strategy, and the compounds were verified using standard solutions. Furthermore, a quantification method for simultaneously targeted analysis of cucurbitacins was established using ultra-high-performance liquid chromatography-tandem mass spectrometry operating in the multiple reaction monitoring mode. Among them, cucurbitacin B and cucurbitacin E in watermelon frost samples were determined, and the concentrations were 3.78 ± 0.18 and 0.86 ± 0.19 ng/ml, respectively. While isocucurbitacin B was not detected due to the lower content possibly. In conclusion, ultra-high-performance liquid chromatography-tandem mass spectrometry combined with molecular networking is a very useful technique for the rapid identification of unknown cucurbitacin components in watermelon frost.     

Identification and quantification of glutathione adducts of clozapine using ultra-high-performance liquid chromatography with orthogonal acceleration time-of-flight mass spectrometry and inductively coupled plasma mass spectrometry

The application of sulphur-specific detection via ultra-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (UPLC/ICPMS) to detect and quantify the glutathione (GSH)-adducts produced via the in vitro formation of reactive metabolites is demonstrated. The adducts were formed in human liver microsomes supplemented with unlabelled GSH for clozapine. The calculation of adduct concentration was performed via comparison of the peak areas to calibration curves constructed from omeprazole, a sulphur-containing compound over the range of 0.156 to 15.62 μM of sulphur with a detection limit of 1.02 ng of sulphur on-column. Identification of the adducts was performed using conventional UPLC/time-of-flight (TOF)-MS with the calculation of clozapine intrinsic clearance carried out by high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). The use of ICPMS in this way appears to offer a novel, rapid and sensitive means of determining the quantity of GSH conjugates with the combined adducts producing 0.9 μM of reactive metabolite out of a total of 3.5 μM of metabolites. The GSH adduct therefore represents 26% of this total produced as a result of the metabolism of drug to reactive species.