Effects of voriconazole and fluconazole on the pharmacokinetics of almonertinib in rats by UPLC–MS/MS

Almonertinib was included in the first-line treatment of non-small cell lung cancer with EGFR T790M mutations by the Chinese Society of Clinical Oncology in 2021. Considering that immunocompromised lung cancer patients are prone to opportunistic fungal infections, and most triazole antifungal drugs are moderate or strong inhibitors of CYP3A4, this study was conducted to develop and validate an accurate and rapid ultra-performance liquid chromatography tandem mass spectrometry method for quantifying almonertinib in plasma and for investigating the pharmacokinetic changes of almonertinib caused by voriconazole and fluconazole in rats. After liquid–liquid extraction with tert-butyl methyl ether, an XSelect HSS T3 column (2.1 × 100 mm, 2.5 μm, Waters) was used for the chromatographic separation of almonertinib and sorafenib-D₃ (internal standard). The analytes were detected using an AB Sciex Triple Quad 5,500 mass spectrometer in the positive ionization mode. The method exhibited great linearity (0.5–200 ng/ml, r > 0.997) and stability under the established experimental conditions. All validation experiments were in accordance with the guidelines, and the results were all within the acceptable limits. This method was successfully applied to the researches of pharmacokinetics and drug interactions for almonertinib in rats. Voriconazole and fluconazole significantly altered the pharmacokinetic profiles of almonertinib and increased the systemic exposure of almonertinib in rats to different degrees, but further human trials should be conducted to validate the results.     

Pharmacokinetic studies of a novel tubulin inhibitor SK1326 in rat plasma by UPLC–MS/MS

A sensitive method for quantitation of SK1326 in rat plasma has been established using ultra-performance liquid chromatography–electrospray ionization tandem mass spectrometry (UPLC–ESI/MS/MS). SK1326 and the internal standard (tramadol) in plasma sample were extracted using acetonitrile. A centrifuged upper layer was then evaporated and reconstituted with a mobile phase of 0.5% formic acid–acetonitrile (35:65, v/v). The reconstituted samples were injected into a C₁₈ reversed-phase column. Using MS/MS in the multiple reaction monitoring mode, SK1326 and tramadol were detected without severe interference from the rat plasma matrix. SK1326 produced a protonated precursor ion ([M + H]⁺) at m/z 432.3 and a corresponding product ion at m/z 114.4. The internal standard produced a protonated precursor ion ([M + H]⁺) at m/z 264.4 and a corresponding product ion at m/z 58.1. Detection of SK1326 in rat plasma by the UPLC–ESI/MS/MS method was accurate and precise with a quantitation limit of 1.0 ng/mL. The validation, reproducibility, stability and recovery of the method were evaluated. The method has been successfully applied to pharmacokinetic studies of SK1326 in rat plasma. The pharmacokinetic parameters of SK1326 were evaluated after intravenous (at a dose of 10 mg/kg) and oral (at a dose of 20 mg/kg) administration of SK1326 in rats. After oral administration (20 mg/kg) of SK1326, the F (fraction absorbed) value was ~77.1%.     

Study of the ESI and APCI interfaces for the UPLC–MS/MS analysis of pesticides in traditional Chinese herbal medicine

In this work, 53 selected pesticides of different chemical groups were extracted from Chinese herbal medicines and determined by ultra-high-performance liquid chromatography (UHPLC)–tandem mass spectrometry (MS/MS) using both electrospray ionization (ESI) and atmospheric-pressure chemical ionization (APCI). Extracts were obtained using the acetonitrile-based quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation technique. Cleanup was performed by dispersive solid-phase extraction using primary secondary amine, graphitized carbon black, and octadecylsilane. Two atmospheric-pressure interfaces, ESI and APCI, were checked and compared. The validation study, including detection limits, linearity, and matrix effects, was conducted on fritillaria, radix ginseng, folium isatidis, semen persicae, and flos lonicerae in multiple reaction monitoring mode. These matrices represent a variety of plants used in traditional Chinese medicine. Fritillaria and radix ginseng were chosen as representatives for roots, folium isatidis was chosen as a representative for leaves, semen persicae was chosen as a representative for seeds, and flos lonicerae was chosen as a representative for flowers. The limits of detection for pesticides were lower in the UHPLC–ESI-MS/MS method than in the UHPLC–APCI-MS/MS method. Matrix effects on the two ionizations were evaluated for the five matrices. Soft signal enhancement in UHPLC–APCI-MS/MS and signal suppression in UHPLC–ESI-MS/MS were observed.

Identification of the absorptive constituents and their metabolites in vivo of Ziziphi Spinosae Semen by UPLC–ESI–Q-TOF–MS/MS

In this research, ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC–ESI–Q-TOF–MS/MS) was used for detection and identification of the absorptive constituents and their metabolites in rat plasma, urine and feces following oral administration of Ziziphi Spinosae Semen alcohol extract. After structure elucidation, a total of 12 compounds in rat plasma, comprising seven prototypes and five metabolites, 28 compounds in urine, comprising 17 prototypes and 11 metabolites, and 23 compounds in feces, comrpising 17 prototypes and six metabolites, have been tentatively identified by comparison with standard compounds and reference literature information. To the best of our knowledge, this is the first comprehensive and systematical metabolic study on the seed. Mostly importantly, we propose that gastric acid could convert jujubosides into an absorbable form of ebelin lactone oligosaccharides, which may be responsible for the low bioavailability and specific bioactivities of these compounds. Additionally, we deduced that the absorption site of ebelin lactone oligosaccharides is located in the stomach, and that the ebelin lactone form of jujubosides may be more suitable for absorption than its hydrolysis product. Our investigation will be helpful to narrow the scope for potentially active ingredients of the seed, and pave the way for determination of the pharmacological mechanism of the seed.     

Investigation of electrochemical behavior of anisomycin on gold electrode followed by HPLC–MS/MS analysis

Anisomycin is an immunosuppressant in low doses (< 0.1 μM) with possible application in treatment of some autoimmune diseases and in inhibiting transplantation rejection. Anisomycin suppresses malignant tumor cell growth and affects memory. For the first time it was the subject of the electrochemical investigations by cyclic voltammetry and square wave voltammetry on gold electrode in 0.05 M NaHCO₃ using its electrochemical activity. The cyclic voltammetry experiments at different sweep rates show that electrochemical process is irreversible and diffusion controlled. Based on square wave voltammetry measurements, the calculated values of LOD and LOQ were 1 and 4 nM (in the absence of biological fluid), as well as 2 and 6 nM (in the presence of spiked urine) indicating the high sensitivity of the proposed electroanalytical method. High performance liquid chromatography–tandem mass spectrometry was a reference method for quantification of anisomycin and served for structural identification of its hydrolysis product (deacetylanisomycin).     

Studies of the intestinal absorption of the alkaloids in the Wu-tou decoction combined with different incompatible medicinal herbs in a Caco-2 cell culture system using UPLC-MS/MS

In this study, seven alkaloids were detected in Wu-tou decoction using ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MSn). The aim of this study was to investigate the effect of Fritillariae Cirrhosae Bulbus, Fritillariae Thunbergii Bulbus, Pinelliae Rhizoma in different ratios with Wu-tou decoction (2:1, 1:1, 1:2) by measuring the therapeutic effects in Wu-tou decoction of main seven alkaloids including benzoylaconitine (BA), benzoylmesaconitine (BM), benzoylhypaconitine (BH), hypaconitine (HA), fuziline (FU), niaolin (NE) and deoxyaconitine (DA). The permeability of aconitum alkaloids extract through a Caco-2 cell monolayer was analyzed in the absence and presence of Fritillariae Cirrhosae Bulbus, Fritillariae Thunbergii Bulbus, and Pinelliae Rhizoma, respectively. The results showed that Pinelliae Rhizoma could reduce the absorption of the alkaloids and increase the excretion of the alkaloids, which would attenuate the therapeutic effects of Wu-tou decoction. Therefore, Pinelliae Rhizoma is an incompatible herb of Wu-tou decoction because of the inhibition of the absorption of alkaloids in the intestine. And that Fritillariae Cirrhosae Bulbus and Fritillariae Thunbergii Bulbus showed the effects to improve the permeability of the alkaloids in Wu-tou decoction. These effects of these two herbs were similar, but the former was stronger than the latter, which most likely is due to the fact that the compositions of these two traditional Chinese medicines are similar. The in vitro data suggests that the compounds such as fritillary presented in alkaloids in the formula maybe improve the therapeutic function caused by the increased bioavailability of alkaloids in intestine.     

UPLC-MS/MS法测定中药材中齐墩果酸与熊果酸的含量

建立了一种同时检测中药材中齐墩果酸(OA)和熊果酸(UA)含量的超高效液相色谱串联质谱方法。采用超高效液相色谱-三级四极杆质谱(UPLC-TQMS)法对样品进行测定,Waters Acquity UPLC BEH C_(18)色谱柱(50 mm×2.1 mm,1.7μm)进行分离,以乙腈-5 mmol/L乙酸铵水溶液(氨水调至pH 9.24)为流动相,梯度洗脱;负离子模式下检测。结果表明,齐墩果酸和熊果酸在0.5~50.0 ng/mL浓度范围内线性关系良好,相关系数(r~2)分别为0.999 8和0.999 7;检出限(S/N=3)分别为0.006 6,0.012 8 ng/mL,定量下限(S/N=10)分别为0.002 0,0.003 8 ng/mL;对OA和UA进行加标回收实验,平均回收率分别为101.1%和100.8%,相对标准偏差(RSD,n=9)分别为1.8%和0.04%。对10种不同中药材中齐墩果酸和熊果酸含量进行检测,结果表明该方法快速简便、准确度高、重现性好,可用于含有齐墩果酸和熊果酸的中药材含量测定。     

Development and validation of a sensitive assay for the quantification of imatinib using LC/LC‐MS/MS in human whole blood and cell culture

We developed and validated a semi‐automated LC/LC‐MS/MS assay for the quantification of imatinib in human whole blood and leukemia cells. After protein precipitation, samples were injected into the HPLC system and trapped onto the enrichment column (flow 5 mL/min); extracts were back‐flushed onto the analytical column. Ion transitions [M + H]⁺ of imatinib (m/z = 494.3 → 394.3) and its internal standard trazodone (372.5 → 176.3) were monitored. The range of reliable response was 0.03–75 ng/mL. The inter‐day precisions were: 8.4% (0.03 ng/mL), 7.2% (0.1 ng/mL), 6.5% (1 ng/mL), 8.2% (10 ng/mL) and 4.3% (75 ng/mL) with no interference from ion suppression. Autosampler stability was 24 hs and samples were stable over three freeze–thaw cycles. This semi‐automated method is simple with only one manual step, uses a commercially available internal standard, and has proven to be robust in larger studies. Copyright © 2009 John Wiley & Sons, Ltd.     

Toxaphene analysis in Great Lakes fish: a comparison of GC-EI/MS/MS and GC-ECNI-MS, individual congener standard and technical mixture for quantification of toxaphene

Toxaphene is considered to be a problematic organochlorine pollutant because of its bioaccumulation potential and persistence in aquatic environments. In this study, whole lake trout and walleye composites were used to evaluate two analytical techniques for total toxaphene and selected congener analysis. The efficacy of using gas chromatography electron ionization tandem mass spectrometry (GC-EI/MS/MS) and electron capture negative ionization mass spectrometry (GC-ECNI-MS) were compared. Although the sensitivity using GC-ECNI-MS was approximately five times greater than GC-EI/MS/MS, the latter provided more consistent inter-Parlar relative response factors (RRF). When using technical calibration mixtures, these results suggest a more accurate total toxaphene measurement was obtained using the GC-EI/MS/MS method. Total toxaphene concentrations in lake trout composites from both methods were highly correlated (R ² = 0.985) with the MS/MS concentrations approximately half of those determined by ECNI, suggesting systematic high bias in toxaphene concentrations when measured using GC-ECNI.     

超声辅助分散液液微萃取/超高效液相色谱-串联质谱法检测水中多种磺胺类抗生素残留

建立了水中13种磺胺类抗生素的超声辅助分散液液微萃取/超高效液相色谱-串联质谱(UADLLME/UPLC-MS/MS)测定方法。以乙腈为分散剂,四氯乙烷为萃取剂,通过超声分散方式协同萃取水样中的目标化合物,采用C_(18)(色谱柱(100 mm×2.1 mm,1.7μm)分离,以乙腈-0.1%甲酸溶液为流动相,采用UPLC-MS/MS多反应监测模式(MRM)测定。优化了萃取剂和分散剂的类型和用量、萃取时间、氯化钠浓度和p H值等条件。在优化条件下,13种磺胺类抗生素在一定质量浓度范围内线性关系良好,相关系数均大于0.998,方法检出限(S/N=3)为0.6~2.4 ng/L;3个加标水平的平均回收率为80.3%~101.8%,相对标准偏差(RSD,n=5)为0.7%~4.5%。该方法前处理简单、环保、灵敏,适用于水样中多种磺胺类抗生素的测定。     

高效液相色谱-三重四极杆质谱法同时测定新型“香料”毒品中的10种合成大麻素

为测定新型"香料"毒品中常见的合成大麻素成分,研究开发了高效液相色谱-三重四极杆质谱联用分析方法。采用安捷伦Poroshell 120 EC-C18(3.0 mm×50 mm,2.7μm)色谱柱,以高纯水-甲醇作流动相进行梯度洗脱,柱温30℃,流速0.3 m L/min。采用电喷雾电离-正离子(ESI+)、负离子(ESI-)分段检测模式,并对合成大麻素的质谱特征和离子碎裂规律进行研究。结果表明,采用该方法可以实现对常见10种合成大麻素的定性和定量分析,正、负离子模式下检测的目标物分别在1~100,10~1 000 ng/m L范围内呈良好线性,日内相对标准偏差(RSD)均不大于3.2%,日间RSD均不大于6.3%。经加标回收率测定和实际样本检验,该方法快速、准确、灵敏、可靠,适用于新型"香料"毒品中常见合成大麻素成分的定性定量检测。     

高效液相色谱-串联质谱法测定食品包装材料中全氟辛烷磺酰基化合物(PFOS)

建立了用高效液相色谱-串联质谱(HPLC/MS/MS)结合快速溶剂萃取测定食品包装材料中全氟辛烷磺酰基化合物(PFOS)的方法。采用乙腈溶剂,快速溶剂提取食品包装材料中的PFOS,提取液经0.2μm有机滤膜过滤后,以V(乙腈)∶V(10 mmol/L乙酸铵溶液)=80∶20为流动相,经HPLC分离后用多级反应监测(MRM)方式测定。用两个子离子的相对丰度定性,外标法定量。PFOS在0.002~0.1μg/mL范围内线性良好(R2=0.998),回收率为93.8%~101%,精密度RSD为1.6%~3.1%,方法检出限为0.4μg/m2(S/N≥10),满足欧盟法规对食品包装材料中PFOS的限量检测要求。方法可用于食品包装材料中PFOS的检测。     

超高效液相色谱-电喷雾串联质谱法测定饲料中残留的三聚氰胺

饲料样品经1%三氯乙酸-二甲基亚砜提取,Waters Oasis MCX柱净化,超高效液相色谱分离,最终采用电喷雾串联四极杆质谱进行检测。结果表明,三聚氰胺在饲料中的含量范围为10～5000 μg/kg时,线性关系良好(r＞0.99)。在10～100 μg/kg 的添加水平范围内的平均回收率为83%～94%,相对标准偏差为4.2%～6.5%。该方法的检出限为10 μg/kg。     

Analysis of Low-polar Ginsenosides in Steamed Panax Ginseng at High-temperature by HPLC-ESI-MS/MS

A high performance liquid chromatography coupled with electrospray ionization-tandem mass spectrometry( HPLC-ESI-MS/MS) method was developed for the analysis and identification of ginsenosides in the extracts of raw Panax ginseng(RPG) and steamed Panax ginseng at high temperatures(SPGHT). A total of 25 ginsenosides were extracted include of which 10 low-polar ginsenosides, such as ginsenosides F4, Rk3, Rh4, 20S-Rg3, 20R-Rg3 and so on, were identified according to their HPLC retention time and MS/MS data. The results indicated that the low polar ginsenosides were seldom found in RPG. For the exploration of the transformation pattern of the ginsenosides in steam processing, the standards of ginsenosides Re, Rg1, Rb1, Rc, Rb2, Rb3 and Rd were selected and hydrolyzed at a temperature of 120 ℃. The results show that these polar ginsenosides can be converted to low-polar ginsenosides such as Rg2, Rg6, F4, Rk3 and Rg5 by hydrolyzing the sugar chains.     

Rapid Determination of Tetrodotoxin in Human Plasma by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

A sensitive analytical method was developed to determine tetrodotoxin(TTX) in human plasma samples using protein precipitation, followed by ultra performance liquid chromatography(UPLC) analysis coupled with tandem mass spectrometry(MS/MS) using 11-deoxytetrodotoxin(11-deoxyTTX) as an internal standard. The plasma samples were prepared using protein precipitation prior to being analyzed by UPLC-MS/MS to identify TTX over a zwitterionic-hydrophilic interaction liquid chromatography column. The retention time values of TTX and 11-deoxyTTX were 4.12 and 3.67 min, respectively. TTX and 11-deoxyTTX were monitored and quantitated on the basis of their ion transitions for their respective precursor ions to their product ions(i.e., m/z 320.0→162.1 for TTX and m/z 304.0→176.0 for 11-deoxyTTX) in the multiple reaction-monitoring mode. The lower limit of quantification of this method was determined to be 0.0199 ng/mL. This method showed good linearity for plasma samples that contained TTX concentrations in the range of 0.0199-1.99 ng/mL. The specificity, precision, accuracy, matrix effect, and stability characteristics of this method were also examined. The intra-assay precision and accuracy ranged from 1.89% to 6.00% and from 92.21% to 100.00%, whereas the inter-assay precision and accuracy ranged from 0.64% to 7.75% and from 99.38% to 101.26%, respectively. This new method therefore represents a rapid, accurate, reliable, and highly sensitive method for the qualitative and quantitative analyses of a trace amount of TTX in human plasma samples.