Tandem Mass Spectrometry Method Research Articles

Development and Validation of a UHPLC-MS/MS Method for the Simultaneous Quantification of Candesartan and Bisoprolol Together with Other 16 Antihypertensive Drugs in Plasma Samples.

Antihypertensive pharmacological therapy is often characterized by a coadministration of different classes of drugs. Therefore, analytical methods allowing the simultaneous quantification of many drugs are needed for therapeutic drug monitoring (TDM) purposes in this context. In particular, TDM represents a useful tool to discriminate poor adherence from real cases of resistant hypertension. For this reason, the aim of this study is to validate, following the Food and Drug Administration (FDA) and the European Medicines Agency (EMA) guidelines, an ultrahigh-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous quantification of 18 antihypertensive drugs in human plasma. A LX-50 coupled with a QSight 220 UHPLC-MS/MS system with electrospray ionization and multiple reaction monitoring mode was used, after a binary gradient separation (13 min) on a reverse-phase Acquity UPLC HSS T3 [1.8 μm, 2.1 mm × 150 mm] column. Method validation showed a stable and acceptable matrix effect, recovery, high accuracy, and precision, assessing the eligibility of this method for routine use in the clinical context.

Development and Validation of an Eco-Friendly Liquid Chromatography- Tandem Mass Spectrometry Method for Rapid Quantification of Γ-Aminobutyric Acid in Cordyceps sinensis and its Related Species

Introduction: Cordyceps sinensis, a renowned traditional Chinese medicinal substance, contains pharmacologically beneficial compounds, including γ-aminobutyric acid (GABA), necessitating efficient analytical methods for quality assessment. This study aims to develop a rapid, cost-effective, and eco-friendly liquid chromatography-tandem mass spectrometry (LC–MS/MS) method for GABA quantification in Cordyceps sinensis and its related species. The objective is to enhance the quality control standards within the Cordyceps sinensis industry and for those of its related species. Methods: The study innovated a swift analytical procedure. Optimal conditions were determined through systematic evaluations of extraction solvents, durations, and chromatographic settings, prioritizing speed and solvent minimization. Results: The proposed LC–MS/MS method achieved precise quantification of GABA in a reduced time frame and significantly lowered solvent consumption, enhancing method efficiency by 22-fold compared to reported LC methods. The method exhibited robustness and scored the highest blue applicability grade index score, underscoring its suitability for academic and industrial applicaition. Conclusion: The validated LC–MS/MS approach offers a sustainable avenue for the rapid and accurate measurement of GABA in Cordyceps sinensis and its related species, improving the quality control process and ensuring product authenticity. This method stands out as a model for green analytical chemistry, propelling forward the eco-friendly analytical evaluation of health-related compounds.

Evaluation of a New Tandem Mass Spectrometry Method for Sickle Cell Disease Newborn Screening.

In France, sickle cell disease newborn screening (SCD NBS) has been targeted to at-risk regions since 1984, but generalization to the whole population will be implemented from November 2024. Although tandem mass spectrometry (MS/MS) is already used for the NBS of several inherited metabolic diseases, its application for SCD NBS has not been widely adopted worldwide. The aim of this study was to evaluate a dedicated MS/MS kit (Targeted MS/MS Hemo, ZenTech, LaCAR Company, Liege, Belgium) for SCD NBS and to compare the results obtained with those from an NBS reference center using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) and cation-exchange high-performance liquid chromatography (CE-HPLC, Variant NBS, Biorad Laboratories, Inc., Hercules, CA, USA) as confirmatory method. The MS/MS Hemo kit was used according to the manufacturer's instructions and performed on a Waters Xevo TQ-D (Waters Corporation, USA). The software provided by the manufacturer was used for the calculation and analysis of peptide signal ratios. Among the 1333 samples, the results of 1324 samples were consistent with the HPLC and/or MALDI-TOF results (1263 FA, 50 FAS, 7 FAC, 1 FAO-Arab, and 3 FS). All the discordant results (one FAS on MS/MS vs. FA in CE-HPLC, one FA on MS/MS vs. FAS in CE-HPLC, seven FS on MS/MS vs. FAS in CE-HPLC) were corrected after modifying the peptide signal ratios thresholds, allowing the MS/MS Hemo kit to achieve near-100% sensitivity and specificity for SCD NBS. In conclusion, the MS/MS Hemo kit appears to be an effective method for SCD NBS, particularly for laboratories already equipped with MS/MS technology. However, these results should be confirmed in a larger cohort including a greater number of positive samples for SCD.

A sensitive UHPLC-electrospray tandem mass spectrometry method for the simultaneous quantification of 8 oxysterols and cholesterol in oysters (Crassostrea gigas) with different thermal cooking procedures

A sensitive UHPLC-electrospray tandem mass spectrometry method for the simultaneous quantification of 8 oxysterols and cholesterol in oysters (Crassostrea gigas) with different thermal cooking procedures

Development of a straightforward direct injection UHPLC-MS/MS method for quantification of plastic additive chemicals in roadside retention ponds

There is growing interest in road pollution that enters surface waters. Additive chemicals used in the manufacture of plastics, including tyre rubber, are mobile pollutants that pose a threat to aquatic life. Therefore, an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method was developed to measure 25 plastic additive chemicals in road runoff and water of retention ponds used to manage road runoff. A straightforward direct injection methodology was adopted to minimise sample handling and risk of contamination. Using this approach, the method quantitation limits (MQLs) ranged from 4.3 × 10−3 to 13 µg/L. These were adequate to determine most chemicals at or below their freshwater predicted no-effect concentration (PNEC). Method trueness ranged from 18 to 148% with most chemicals being within 80–120%. The method was applied to water from four retention ponds in series to measure additive chemicals entering the ponds (i.e., in road runoff) and passing through each pond. Greatest concentrations were observed in road runoff during heavy rainfall following dry weather. Here, 1,3-diphenylguanidine (DPG) exceeded its current PNEC of 1.05 µg/L. Notably, N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine-quinone (6PPD-quinone) was determined at 0.13 µg/L which is greater than its lowest acute toxicity threshold (0.095 µg/L). Similarity in additive chemical concentrations throughout the retention ponds during steady flow suggests little or no removal occurs. However, further studies are needed to assess the fate and removal of plastic additive chemicals in retention ponds and the risk posed to aquatic environments. Such research can be facilitated by this newly developed UHPLC-MS/MS method.Graphical

Determination of Sennoside A in Rat Plasma by Liquid Chromatography/Electrospray Ionization Tandem Mass Spectrometry and Its Application to a Rat Pharmacokinetic Study.

To characterize pharmacokinetic profile of sennoside A in rats after intravenous and oral administration, a simple and sensitive liquid chromatography tandem mass spectrometry method was established and validated for quantitative determination of sennoside A in rat plasma. After prepared by protein precipitation with acetonitrile, sennoside A and internal standard were separated on a Waters ACQUITY HSS T3 (2.1 × 100 mm, 1.8 μm) column using acetonitrile and 5-mM ammonium acetate in water as mobile phase by gradient elution. The method showed excellent linearity over the range of 0.5-1000 ng/mL with acceptable intra- and inter-day precision, accuracy, matrix effect, and recovery. The stability assay indicated that sennoside A was stable in plasma during the sample collection, preparation, and analysis. Next, the method was applied to pharmacokinetic study of sennoside A in rats. After intravenous and intragastric administrated to rats, the concentrations of sennoside A in plasma at different time points were quantitated and the pharmacokinetic parameters were calculated by software of DAS 2.0. Pharmacokinetic parameters suggested that after oral administration, sennoside A was reached to the peak at 2.9-3.6 h with a Cmax value of 13.2-31.7 ng/mL. Sennoside A was eliminated slowly from the plasma with T1/2 value between 15.4 and 18.3 h. The oral absolute bioavailability was among 0.9%-1.3%, which indicated low blood exposure level.

Detection of "smoke powder" etomidate and its metabolite etomidate acid in blood and urine by UHPLC-MS-MS: application in authentic cases.

Recently, etomidate has been widely used as an alternative in illicit drug market. It is usually added to regular cigarette tobacco (commonly known as "cigarette powder") or mixed in e-cigarette oil sold through the Internet, retail stores, or entertainment outlets and other channels. An ultra-high performance liquid chromatography tandem mass spectrometry method was developed to quantify etomidate and etomidate acid in human blood and urine. The limit of detection (LOD) of etomidate and etomidate acid in blood is 0.5 and 2 ng/mL, respectively, and the lower limit of quantification (LLOQ) is 1 and 5 ng/mL, respectively. The LOD of etomidate and etomidate acid in urine is 1 and 2 ng/mL, respectively, and the LLOQ is 2 and 5 ng/mL, respectively. The precision, accuracy, recoveries, and matrix effects of etomidate and etomidate acid determinations in blood and urine met the requirements for methodological validation. The method was successfully applied to the identification and quantification of etomidate and etomidate acid in blood and urine of 62 forensic cases. The concentration of etomidate ranged from 1.52 to 8.41 ng/mL (positive cases, n = 5) and the concentration of etomidate acid ranged from 2.76 to 112 ng/mL (positive cases, n = 5) in blood. The concentrations of etomidate and etomidate acid in urine samples were 2.64-79,300 ng/mL (positive cases, n = 59) and 6.11-518,000 ng/mL (positive cases, n = 60), respectively. Therefore, the concentration of etomidate in blood and urine is mostly higher than that of etomidate.

The validation of an LC-MS/MS method for the quantification of vitamin D metabolites in human milk and their biological variability in Gambian women

Vitamin D is required for healthy growth and development, but data on human milk vitamin D content is limited. We describe a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the analysis of vitamin D metabolites in human milk, and its application in samples collected on two consecutive days from women in rural Gambia. Vitamin D compounds were extracted from 1 mL of milk by liquid-liquid extraction and derivatised with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) prior to analysis by LC-MS/MS. The limit of quantification was 0.05 nmol/L for vitamin D2, 0.025 nmol/L for vitamin D3 and 0.1 nmol/L for 25(OH)D2 and 25(OH)D3. Within- and between-day imprecision was <12 % for all analytes except vitamin D2 (14 %).From all data combined, geometric mean (-/+ 1 SD) vitamin D3 concentration was 0.94 (0.43, 1.80) nmol/L and for 25(OH)D3 0.32 (0.23, 0.42) nmol/L. The within-person (intra-individual) coefficient of variation (%CV) was 32 % and 12 % for vitamin D3 and 25(OH)D3, respectively. Between-person (inter-individual) %CVs were 89 % and 34 % for vitamin D3 and 25(OH)D3, respectively. There was no significant association between vitamin D metabolite concentrations and milk fat (creamatocrit). Mean vitamin D content of human milk as ARA averaged 42 IU/L with 25(OH)D3 responsible for around two-thirds of the biological activity. In conclusion, this work describes a reliable LC-MS/MS method for quantification of vitamin D and 25(OH)D in low volumes of human milk providing a platform for future work. This study contributes to current understanding of variability of milk vitamin D content.

Study on the Determination of Perfluorocarboxylic Acids (PFCAs) in House Dust Samples by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) Method

Perfluorocarboxylic acids (PFCAs) are an important group of per- and polyfluoroalkyl substances (PFAS), which have been intensively produced and used due to their outstanding features such as high resistance and water and oil repellency. However, these are also typical organic pollutants with several adverse effects on environmental and human health. Studies on the analytical methods for PFAS in general, and PFCAs in particular, in the environments are necessary to characterize their potential emission sources and related health risks. In this study, analytical procedure for simultaneous determination of 12 PFCAs (C5–C18) in house dust samples was developed with 3 main steps: i) Dust samples were extracted by ultrasonication with methanol; ii) Dust extracts were cleaned up by dispersive solid phase extraction with graphitized carbon sorbent; and iii) Concentrations of PFCAs were determined by liquid chromatography tandem mass spectrometry (LC-MS/MS) method. The method was validated for recovery (72-95%), repeatability (RSD &lt; 15%), and detection limits (0.10-1.0 ng/g). The proposed analytical method can be applied in pollution monitoring and assessment of PFCAs in settled dusts with several advantages like high accuracy, good detection ability at trace and ultratrace levels (i.e., ng/g or lower) with rapid, simple sample preparation procedure.

Development and validation of ultra-performance liquid chromatography tandem mass spectrometry methods for the quantitative analysis of the antiparasitic drug DNDI-6148 in human plasma and various mouse biomatrices

Development and validation of ultra-performance liquid chromatography tandem mass spectrometry methods for the quantitative analysis of the antiparasitic drug DNDI-6148 in human plasma and various mouse biomatrices

Simultaneous quantification of serum symmetric dimethylarginine, asymmetric dimethylarginine and creatinine for use in a routine clinical laboratory.

BackgroundSymmetric dimethylarginine (SDMA) and asymmetric dimethylarginine (ADMA) are naturally occurring amino acids classed as uraemic toxins by the European Uremic Toxins Work Group. SDMA is principally excreted through the kidneys and is a well-known renal function marker, and ADMA is a potent inhibitor of nitric oxide production. Here, we describe the development of a rapid and sensitive liquid chromatography tandem mass spectrometry method for simultaneous measurement of SDMA, ADMA and creatinine.MethodSerum samples were prepared by protein precipitation and dilution with acetonitrile prior to injection onto a Waters TQS-Micro. SDMA, ADMA, creatinine and their corresponding internal standard transitions were detected using multiple reaction monitoring after separation with a hydrophilic interaction liquid chromatography analytical column. Sample stability and intra-individual variation studies were also assessed following ethical approval.ResultsThe retention time for creatinine was 0.43, SDMA 1.10 and ADMA 1.14min. Mean recovery for creatinine was 103%, SDMA was 100% and ADMA was 103%; matrix effects were minimal (<6%). Lower limit of quantitation for creatinine and SDMA/ADMA was 17.5µmol/L and 0.1µmol/L, respectively. Analytical imprecision showed a coefficient of variation <10% for all analytes across the working range of the assays. Intra-individual variation for creatinine was 4.7%, SDMA 7.5% and ADMA 7.6%.DiscussionWe have developed a rugged assay for measurement of SDMA, ADMA and creatinine by LC-MS/MS suitable for routine use. It is easy to perform owing to its simplicity and reproducibility. The stability of SDMA and ADMA pre- and post-centrifugation allows for their routine use without any special sample handling requirements.

Bioactivity-Based Analysis and Chemical Characterization of Hypoglycemic Components from Helicteres angustifolia L.

Helicteres angustifolia L. (H. angustifolia), a well-known traditional Chinese medicine, has been demonstrated to have hypoglycemic activity. We found that the EtOAc extract of H. angustifolia (HAEF) showed stronger α-glucosidase inhibitory activity than that of positive control. Furthermore, the hypoglycemic activity of HAEF was evaluated in streptozotocin (STZ)-induced type 2 diabetes mellitus (T2DM) rats. The results demonstrated that HAEF reduced the drinking quantity, feeding quantity, and controlled weight loss in diabetic rats. Besides, the fasting blood glucose (FBG), viscera index, and the area under time-blood glucose curve (AUC) were significantly decreased, and the oral glucose tolerance was also improved after 5 weeks. Then, the high-performance liquid chromatography with quadrupole time of flight tandem mass spectrometry (HPLC-Q-TOF-MS/MS) method was performed for qualitative analysis of the chemical constituents in HAEF. Twenty-one compounds were identified from in HAEF. Four compounds were further isolated from HAEF and subjected to α-glucosidase inhibition experiments. At the end, molecular docking was empolyed simulate the interaction of three compounds with α-glucosidase. This is the first report on major hypoglycaemic components has been identified in the roots of H. angustifolia. These findings provide a material basis for the use of H. angustifolia in the treatment of diabetes.

Zic-HILIC MS/MS Method for NADomics Provides Novel Insights into Redox Homeostasis in Escherichia coli BL21 Under Microaerobic and Anaerobic Conditions.

Background: Nicotinamide adenine dinucleotide (NAD+), its precursors, and its derivatives (collectively NADome) play a crucial role in cellular processes and maintain redox homeostasis. Understanding the dynamics of these metabolic pools and redox reactions can provide valuable insights into metabolic functions, especially cellular regulation and stress response mechanisms. The accurate quantification of these metabolites is challenging due to the interconversion between the redox forms. Methods: Our laboratory previously developed a zwitterionic hydrophilic interaction liquid chromatography (zic-HILIC)-tandem mass spectrometry method for the quantification of five essential pyridine nucleotides, including NAD+ derivatives and it's reduced forms, with 13C isotope dilution and matrix-matched calibration. In this study, we have improved the performance of the chromatographic method and expanded its scope to twelve analytes for a comprehensive view of NAD+ biosynthesis and utilization. The analytical method was validated and applied to investigate Escherichia coli BL21 under varying oxygen supplies including aerobic, microaerobic, and anaerobic conditions. Conclusions: The intracellular absolute metabolite concentrations ranged over four orders of magnitude with NAD+ as the highest abundant, while its precursors were much less abundant. The composition of the NADome at oxygen-limited conditions aligned more with that in the anaerobic conditions rather than in the aerobic phase. Overall, the NADome was quite homeostatic and E. coli rapidly, but in a minor way, adapted the metabolic activity to the challenging shift in the growth conditions and achieved redox balance. Our findings demonstrate that the zic-HILIC-MS/MS method is sensitive, accurate, robust, and high-throughput, providing valuable insights into NAD+ metabolism and the potential significance of these metabolites in various biological contexts.

UHPLC-MS/MS analysis of the influence of paclobutrazol application on Ophiopogon japonicus

UHPLC-MS/MS analysis of the influence of paclobutrazol application on Ophiopogon japonicus

A novel, sensitive, and fast ultra-high-performance liquid chromatography tandem mass spectrometry method for TNG908 determination in dog plasma and pharmacokinetic study.

TNG908 is a potent and selective protein arginase methyltransferase 5 (PRMT5) inhibitor that is currently going through phase I/II clinical development for the treatment of non-small cell lung cancer. To facilitate pharmacokinetic and toxicokinetic studies of TNG908, here, we reported an ultra-high-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the detection of TNG908 in dogs. The dog plasma samples were precipitated by acetonitrile and analyzed using a Waters ACQUITY BEH C18 column combined with a Thermo triple quadrupole mass spectrometer. The mobile phase consisted of 0.1% formic acid solution and acetonitrile, at a flow rate of 0.3mL/min. TNG908 and internal standard were monitored by selective reaction monitoring (SRM) with m/z 410.2 > 150.1 and m/z 394.2 > 278.1, respectively. The method demonstrated excellent linearity over the concentration range of 1-1000 ng/mL, with a correlation coefficient greater than 0.995. Acetonitrile-mediated protein precipitation showed high extraction efficiency and a recovery above 80%. The validated assay was further applied to measure TNG908 in dog plasma after oral and intravenous administration and achieved success. The obtained pharmacokinetic parameters indicated low clearance of TNG908 (3.7 ± 0.8mL/min/kg) and moderate oral bioavailability (>36.4%).

A single-center prospective study of vitamin D levels and its supplementary effect in the first trimester

Objective: To investigate vitamin D levels and the effect of exogenous vitamin D supplementation in the first trimester among pregnant women in our center. Methods: This was a prospective cohort study. A total of 98 women in the first trimester who were followed-up regularly in Peking Union Medical College Hospital from December 1st 2020 to December 1st 2021 were enrolled. Subjects who had medical conditions that affect vitamin D absorption or metabolism were excluded. Questionnaires were administered, and 25-hydroxyvitamin D [25(OH)D] levels were detected using liquid chromatography tandem mass spectrometry (LC/MS/MS) method. According to the basic 25(OH)D level, different dosages of exogenous vitamin D were supplemented. After 4 weeks, 25(OH)D levels were detected again to evaluate the effect of supplementation. T test, analysis of variance, χ2 test, and multiple linear regression analysis were used for analysis. Results: The mean age of enrolled subjects was (33.5±4.0) years. The baseline 25(OH)D level was (41.2±20.0) nmol/L. Briefly, 70.4% (69/98) subjects were deficient in vitamin D, and 42.9% (42/98) patients were using vitamin D supplementation at the time of 25(OH)D testing. Single-factor analysis showed that vitamin D supplementation (t=-4.21, P<0.001), season (t=2.59, P=0.011), and nut-eating frequency (t=2.67, P=0.009) were related to 25(OH)D levels. Multiple linear regression analysis showed that only vitamin D supplementation had a relationship with 25(OH)D level (B=13.84, P=0.006). According to the baseline 25(OH)D level, 400-5 000 U/d vitamin D3 was supplemented regularly for (4.1±2.5) weeks, and 25(OH)D levels significantly increased after supplementation [(64.1±18.1) vs (37.3±16.6) nmol/L, t=-9.36, P<0.001]. The ascending range was negatively associated with basic 25(OH)D level (B=-0.66, P<0.001) and positively associated with supplementary dosage (B=0.51, P<0.001). 25(OH)D levels increased by 0.51 nmol/L on average per 1 μg (40 U) of vitamin D supplementation daily. Conclusions: The proportion of vitamin D deficiency was high in the first trimester among pregnant women in our center. Exogenous vitamin D supplementation could significantly increase 25(OH)D levels, and the effect was negatively associated with basic 25(OH)D level but positively associated with supplementary dosage.

Determination of Anti-Diabetic Drugs in Health Supplements by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) Method

The mixing of unpermitted drugs with health supplements to increase effectiveness can cause negative effects to consumers, requiring quality testing of these products. In this study, an analytical method for simultaneously determination of 5 anti-diabetic drugs (ADDs) (i.e., metformin, phenformin, buformin, glibenclamide, and gliclazide) in health supplement samples was developed with a combination of ultrasonic extraction, dispersive solid-phase extraction (d-SPE), and liquid chromatography tandem mass spectrometry (LC-MS/MS). Hard capsule, soft capsule, and liquid samples were extracted with methanol twice, followed by activated carbon addition for extract clean-up and LC-MS/MS quantification. The analytical method was validated through various factors such as: specificity, limit of detection, limit of quantification, linearity, repeatability, and recovery. The method had high precision (mean recovery from 88% to 99%, relative standard deviation lower than 10%) and low detection limit of 0.1 mg/kg, meeting the requirements of detection of these substances at trace to ultra-trace levels in complex sample matrices. The validated method was then applied to analyze concentrations of 5 ADDs in 30 health supplement samples. Metformin was detected at a concentration of 2.20 mg/kg in one hard capsule sample, while the remaining samples did not contain ADDs at detectable levels.

Determination of furmonertinib in human plasma and cerebrospinal fluid by UPLC-MS/MS: Application in lung cancer patients with and without brain metastasis

Determination of furmonertinib in human plasma and cerebrospinal fluid by UPLC-MS/MS: Application in lung cancer patients with and without brain metastasis

Simultaneous Quantification of Carboxylate Enantiomers in Multiple Human Matrices with the Hydrazide-Assisted Ultrahigh-Performance Liquid Chromatography Coupled with Tandem Mass Spectrometry.

Many chiral carboxylic acids with α-amino, α-hydroxyl, and α-methyl groups are concurrently present in mammals establishing unique molecular phenotypes and multiple biological functions, especially host-microbiota symbiotic interactions. Their chirality-resolved simultaneous quantification is essential to reveal the biochemical details of physiology and pathophysiology, though challenging with their low abundances in some biological matrices and difficulty in enantiomer resolution. Here, we developed a method of the chirality-resolved metabolomics with sensitivity-enhanced quantitation via probe-promotion (Met-SeqPro) for analyzing these chiral carboxylic acids. We designed and synthesized a hydrazide-based novel chiral probe, (S)-benzoyl-proline-hydrazide (SBPH), to convert carboxylic acids into amide diastereomers to enhance their retention and chiral resolution on common C18 columns. Using the d5-SBPH-labeled enantiomers as internal standards, we then developed an optimized ultrahigh-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous quantification of 60 enantiomers of 30 chiral carboxylic acids in one run. This enantiomer-resolved method showed excellent sensitivity (LOD < 4 fmol-on-column), linearity (R2 > 0.992), precision (CV < 15%), accuracy (|RE| < 20%), and recovery (80-120%) in multiple biological matrices. With the method, we then quantified 60 chiral carboxylic acids in human urine, plasma, feces, and A549 cells to define their metabolomic phenotypes. This provides basic data for human phenomics and a promising tool for investigating the mammal-microbiome symbiotic interactions.

A liquid chromatography - Tandem mass spectrometry method for determination of ocrelizumab in serum of patients with multiple sclerosis

A liquid chromatography - Tandem mass spectrometry method for determination of ocrelizumab in serum of patients with multiple sclerosis