scholarly journals The Elevation of LC-ESI-Q-TOF-MS Response in the Analysis of Isoquinoline Alkaloids from Some Papaveraceae and Berberidaceae Representatives

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Wirginia Kukula-Koch
Keyword(s):  
Formic Acid ◽  
Flow Rate ◽  
Mobile Phase ◽  
Collision Energy ◽  
Gas Flows ◽  
Isoquinoline Alkaloids ◽  
Gas Temperature ◽  
Operation Parameters ◽  
Capillary Voltage ◽  
Tof Ms

Twenty-five methanol extracts obtained from various representatives of Papaveraceae and Berberidaceae botanical families (genera: Papaver, Argemone, Eschscholzia, Chelidonium, Glaucium, and Berberis) were screened for their alkaloid content in an optimized method suitable for the LC-ESI-Q-TOF-MS analysis. Twelve pharmacologically important isoquinoline alkaloids from four groups, aporphines, benzylisoquinolines, protoberberines, and benzophenanthridines, present in these traditionally used plant species were quantitatively determined in each studied sample, providing their alkaloid profile. A Zorbax Stable Bond RP-18 column and a mobile phase composed of 0.1% formic acid and 0.1% formic acid in acetonitrile (v/v) were used at the flow rate of 0.2 mL/min. A profound study on the optimization of MS response to four groups of isoquinoline alkaloids (validation of capillary voltage, gas flows, nebulizer pressure, skimmer, and fragmentor voltages), repeatability of results, and stability and linearity of measurements were described, showing, among others, 3000 V of capillary voltage, 350°C of gas temperature, 12 L/min of gas flows, nebulizer pressure of 35 psig, 65 V for skimmer voltage, and 30 V for collision energy as the most advantageous operation parameters.

scholarly journals Development and validation of a rapid selective high-throughput LC-MS/MS method for the determination of triclabendazole sulfoxide concentrations in sheep plasma and its use in bioequivalence studies

2021 ◽  
Author(s):  
Lénárd Farczádi ◽  
Álmos Dósa ◽  
Orsolya Melles ◽  
Laurian Vlase
Keyword(s):  
Formic Acid ◽  
Flow Rate ◽  
Mobile Phase ◽  
Liver Fluke ◽  
Internal Standard ◽  
Gradient Elution ◽  
Sample Processing ◽  
Development And Validation ◽  
Analytical Separation

AbstractTriclabendazole is one of the main drugs used to treat liver fluke in livestock. A rapid LC-MS/MS method was developed and validated to determine ovine plasma levels of triclabendazole sulfoxide.A Gemini NX-C18 column was used to achieve analytical separation, with gradient elution of a mobile phase composed of 0.1% formic acid in acetonitril and 0.1% formic acid in water at flow rate of 0.6 mL/min. MRM with positive ESI ionization was used for the detection of triclabendazole sulfoxide (m/z 360.10 from m/z 376.97). Fenbendazole was used as internal standard. Plasma protein precipitation with acetonitrile was used for sample processing.The method was validated with regards to selectivity, linearity (r > 0.9939), within run and between run precision (CV < 8.9%) and accuracy (bias < 8.9%) over the concentration range 1–100 µg/mL plasma.The method developed is simple, selective and can be applied in bioequivalence and bioavailability studies.

Ultrafiltration-based Extraction and LC-MS/MS Quantification of Phenylalanine in Human Blood Sample for Metabolite Target Analysis

2020 ◽  
Vol 17 (1) ◽  
pp. 81-86
Author(s):  
Mustafa Çelebier ◽  
Tuba Reçber ◽  
Emirhan Nemutlu ◽  
Sedef Kır
Keyword(s):  
Ischemic Stroke ◽  
Formic Acid ◽  
Flow Rate ◽  
Mobile Phase ◽  
Heavy Isotope ◽  
Column Temperature ◽  
Human Blood Sample ◽  
Linear Concentration Range ◽  
Metabolite Target Analysis ◽  
Linear Concentration

Background: Phenylalanine is a significant biomarker for various diseases like phenylketonuria, gastric cancers, and ischemic stroke according to recent studies. Methods: In the present study; a simple, sensitive, selective and novel analytical method was validated by using an ultrafiltration-based extraction and LC-MS/MS quantification of phenylalanine in human plasma using 13C phenylalanine heavy isotope. Amicon® Ultra Centrifugal Filter was used for ultrafiltration. Parameters affecting LC separation and MS/MS detection were investigated and optimized. Chromatographic separation was achieved on a Merck SeQuant ZIC-HILIC (100x4.6 mm, 5 μm) at a column temperature of 40°C using a mobile phase of mixture of acetonitrile containing 0.1% formic acid and water containing 0.1% formic acid (50:50 v/v) at a flow rate of 0.35 mL/min. The transitions m/z 167→121 for 13C phenylalanine, m/z 166→120 for phenylalanine itself were monitored using the MRM mode. Result: The assay was linear concentration range of 0.0025 μg/mL to 1.20 μg/mL (R2=0.999). The developed method was validated according to FDA guidelines. The method was found linear, sensitive, precise, accurate, and selective.

Characterization of an Unknown Impurity in Indobufen Tablets by HPLC-Q-TOF MS and NMR

2020 ◽  
Vol 16 ◽  
Author(s):  
Yu Li ◽  
Xiangwen Kong ◽  
Liya Hong ◽  
Chen Yue ◽  
Xinyue Wang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
2D Nmr ◽  
Flight Mass Spectrometry ◽  
Ionization Mode ◽  
Preparative Lc ◽  
Set Up ◽  
Tof Ms

Background: Indobufen is a drug that hinders the aggregation of platelets by reversibly repressing the cyclooxygenase enzyme, further bringing about diminished thromboxane production. During quality control of indobufen tablets, an unknown impurity was detected. Objective: To characterize an unknown impurity in indobufen tablets. Method and Results: A new method compatible with mass spectrometry detection was set up. A C18 column at 35 °C with a mobile phase consisting of aqueous buffer (including ammonium formate) and methanol (35: 65, v/v) was used at a flow rate of 1.0 mL/min at 228 nm. High-performance liquid chromatography quadrupole time-of-flight mass spectrometry mass spectrometry (HPLC-Q-TOF MS) was used to identify the impurity with the electrospray ionization (ESI) source in the positive ionization mode. The results of HPLC-Q-TOF MS analysis indicated that the protonated molecule ions [M + H]+ of the unknown impurity was at m/z 312. Preparative LC method was put into practice with a Prep-C18 column with a mobile phase consisting of water and methanol (20: 80, v/v) at a flow rate of 20.0 mL/min at 228 nm. The assignment of the 1D and 2D NMR signals was performed for the unknown impurity. In addition, possible formation of the novel impurity was also studied. Conclusion: An unknown impurity in indobufen tablets was characterized. The impurity was assigned as 2-(4-(1- hydroxy-3-oxoisoindolin-2-yl) phenyl) butanoic acid.

Chemometric Approach to Evaluate the Parameters Affecting Electrospray: Application of a Statistical Design of Experiments for the Study of Arginine Ionization

2005 ◽  
Vol 11 (4) ◽  
pp. 361-370 ◽  
Author(s):  
Laurence Charles ◽  
Stéphanie Caloprisco ◽  
Salimo Mohameda ◽  
Michelle Sergent
Keyword(s):  
Formic Acid ◽  
Acid Concentration ◽  
Flow Rate ◽  
Mobile Phase ◽  
Gas Flow ◽  
Statistical Design ◽  
Statistical Design Of Experiments ◽  
Experimental Conditions ◽  
Mobile Phase Flow Rate ◽  
Methanol Content

The effects of different experimental parameters on arginine electrospray ionization have been investigated with response surface modeling design. This chemometric technique allows a study of the effects of selected experimental variables and their interactions on the response of an experiment by performing a limited number of analyses. Six variables were studied: methanol content in the liquid phase, formic acid concentration, electrospray voltage, orifice voltage, mobile phase flow rate, and sheath gas flow rate. Signal abundance and signal-to-noise ratio of the protonated molecule and the protonated dimer were measured from the electrospray mass spectra and these four responses were tested by the design. The factor that exhibits the greatest influence on MH+ abundance is shown to be the liquid flow rate whereas the formation of protonated dimers is mainly controlled by the percentage of methanol in the mobile phase. A strong synergic effect of methanol content and formic acid concentration in the liquid has also been demonstrated in the study of noise level. Moreover, the capabilities of the multicriteria optimization method have been demonstrated through the successful prediction of a set of optimal experimental conditions.

Characterization of an Unknown Impurity in Glucosamine Sulfate Sodium Chloride by HPLC-Q-TOF MS and NMR

2019 ◽  
Vol 15 (6) ◽  
pp. 650-660
Author(s):  
Miao Zhang ◽  
Peixi Zhu ◽  
Yue Chen ◽  
Weifang Ni ◽  
Yu Li ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Sodium Chloride ◽  
Flow Rate ◽  
Degradation Product ◽  
Mobile Phase ◽  
High Performance ◽  
2D Nmr ◽  
Glucosamine Sulfate ◽  
Heat Condition ◽  
Tof Ms

Background: Glucosamine sulfate sodium chloride (glucosamine-SP) is mainly used for the treatment of osteoarthritis. During quality control of glucosamine-SP capsules, an unknown impurity was detected. Another unknown degradation product was generated together with above-mentioned impurity in heat condition. Objective: The study aimed to characterize an unknown impurity in glucosamine-SP capsules. Methods: A new volatile HPLC method compatible with mass spectrometry detection was set up. An amino column at 35 °C with a mobile phase consisting of water and acetonitrile (20: 80, v/v) was used at a flow rate of 1.5 ml/min at 297 nm. High-performance liquid chromatography quadrupole time-offlight mass spectrometry (HPLC-Q-TOF MS) was used to identify the impurity with the electrospray ionization (ESI) source in the positive ionization mode. Results: The results of HPLC-Q-TOF MS analysis indicated that the protonated molecule ions [M + H]+ of the unknown impurity and the novel degradation product were both at m/z 287. Preparative LC method was put into practice with a Prep-C18 column with a mobile phase consisting of water and acetonitrile (99: 1, v/v) at a flow rate of 20.0 ml/min at 297 nm. The assignment of the 1D and 2D NMR signals was performed for the unknown impurity. In addition, the formation of impurities was also studied. Conclusion: An unknown impurity and a degradation product in glucosamine-SP capsules were characterized. They were assigned as (1R, 2S, 3R)-1-(5-((S, E)-3, 4-dihydroxybut-1-en-1-yl) pyrazin-2-yl) butane-1, 2, 3, 4-tetraol and (1R, 2S, 3R)-1-(5-((S, Z)-3, 4-dihydroxybut-1-en-1-yl) pyrazin-2-yl) butane- 1, 2, 3, 4-tetraol.

Development, Validation and Application of HPLC Method for Metformin in Rabbit Plasma

2019 ◽  
Vol 15 (6) ◽  
pp. 574-579
Author(s):  
Muhammad Ubaid ◽  
Mahmood Ahmad ◽  
Farhan Ahmad Khan ◽  
Ghulam Murtaza
Keyword(s):  
Flow Rate ◽  
Present Method ◽  
Mobile Phase ◽  
Hplc Method ◽  
Plasma Samples ◽  
Rabbit Plasma ◽  
Uv Detector ◽  
Reverse Phase ◽  
T Values ◽  
Pharmacokinetic Evaluation

Objective:This study was aimed at conducting a pharmacokinetic evaluation of metformin in rabbit plasma samples using rapid and sensitive HPLC method and UV detection.Methods:Acetonitrile was used for protein precipitation in the preparation of plasma samples. Reverse phase chromatography technique with silica gel column (250 mm × 4.6 mm, 5 μm) at 30°was used for the separation purpose. Methanol and phosphate buffer (pH 3.2) mixture was used as a mobile phase with flow rate 0.8 ml/min. The wavelength of UV detector was adjusted at 240 nm.Results:The calibration curve was linear in a range of 0.1-1 µg/ml with R² = 0.9982. The precision (RSD, %) values were less than 2%, whereas, accuracy of method was higher than 92.37 %. The percentage recovery values ranged between 90.14 % and 94.97 %. LOD and LOQ values were 25 ng/ml and 60 ng/ml, respectively. Cmax and AUC0-t values were found to be 1154.67 ± 243.37 ng/ml and 7281.83 ± 210.84 ng/ml.h, respectively after treating rabbits with a formulation containing 250 mg metformin.Conclusion:Based on the above findings, it can be concluded that present method is simple, precise, rapid, accurate and specific and thus, can be efficiently used for the pharmacokinetic study of metformin.

Optimum HPLC Conditions for Determination of Dibucaine HCL, Fluocortolone Pivalate and Fluocortolone Caproate by Using Experimental Design

2018 ◽  
Vol 15 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Bürge Aşçı ◽  
Mesut Koç
Keyword(s):  
Experimental Design ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Acid Mixture ◽  
Solution Stability ◽  
Uv Detector

Introduction:This paper presents the development and validation of a novel, fast, sensitive and accurate high performance liquid chromatography (HPLC) method for the simultaneous quantitative determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical preparations.Experiment:Development of the chromatographic method was based on an experimental design approach. A five-level-three-factor central composite design requiring 20 experiments in this optimization study was performed in order to evaluate the effects of three independent variances including mobile phase ratio, flow rate and amount of acid in the mobile phase.Conclusion:The optimum composition for mobile phase was found as a methanol:water:acetic acid mixture at 71.6 : 26.4 : 2 (v/v/v) ratio and optimum separation was acquired by isocratic elution with a flow rate of 1.3 mL/min. The analytes were detected using a UV detector at 240 nm. The developed method was validated in terms of linearity, precision, accuracy, limit of detection/quantitation and solution stability and successfully applied to the determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical topical formulations such as suppositories and ointments.

scholarly journals Box-Behnken Assisted Validation and Optimization of an RP-HPLC Method for Simultaneous Determination of Domperidone and Lansoprazole

Separations ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 5
Author(s):  
Mohd Afzal ◽  
Mohd. Muddassir ◽  
Abdullah Alarifi ◽  
Mohammed Tahir Ansari
Keyword(s):  
Flow Rate ◽  
Mobile Phase ◽  
Limit Of Detection ◽  
Hplc Method ◽  
Box Behnken Design ◽  
Rp Hplc ◽  
System Suitability ◽  
Method Optimization ◽  
Key Variables

A highly specific, accurate, and simple RP-HPLC technique was developed for the real-time quantification of domperidone (DOMP) and lansoprazole (LANS) in commercial formulations. Chromatographic studies were performed using a Luna C8(2), 5 μm, 100Å, column (250 × 4.6 mm, Phenomenex) with a mobile phase composed of acetonitrile/2 mM ammonium acetate (51:49 v/v), pH 6.7. The flow rate was 1 mL·min−1 with UV detection at 289 nm. Linearity was observed within the range of 4–36 µg·mL−1 for domperidone and 2–18 µg·mL−1 for lansoprazole. Method optimization was achieved using Box-Behnken design software, in which three key variables were examined, namely, the flow rate (A), the composition of the mobile phase (B), and the pH (C). The retention time (Y1 and Y3) and the peak area (Y2 and Y4) were taken as the response parameters. We observed that slight alterations in the mobile phase and the flow rate influenced the outcome, whereas the pH exerted no effect. Method validation featured various ICH parameters including linearity, limit of detection (LOD), accuracy, precision, ruggedness, robustness, stability, and system suitability. This method is potentially useful for the analysis of commercial formulations and laboratory preparations.

4-Nitrophenol in 4-nitrophenyl phosphate, a substrate for alkaline phosphatase, as measured by paired-ion high-performance liquid chromatography.

1977 ◽  
Vol 23 (12) ◽  
pp. 2288-2291 ◽  
Author(s):  
P H Culbreth ◽  
I W Duncan ◽  
C A Burtis
Keyword(s):  
Alkaline Phosphatase ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Nitrophenyl Phosphate ◽  
Phase Column ◽  
Reversed Phase Column

Abstract We used paired-ion high-performance liquid chromatography to determine the 4-nitrophenol content of 4-nitrophenyl phosphate, a substrate for alkaline phosphatase analysis. This was done on a reversed-phase column with a mobile phase of methanol/water, 45/55 by vol, containing 3 ml of tetrabutylammonium phosphate reagent per 200 ml of solvent. At a flow rate of 1 ml/min, 4-nitrophenol was eluted at 9 min and monitored at 404 nm; 4-nitrophenyl phosphate was eluted at 5 min and could be monitored at 311 nm. Samples of 4-nitrophenyl phosphate obtained from several sources contained 0.3 to 7.8 mole of 4-nitrophenol per mole of 4-nitrophenyl phosphate.

scholarly journals RP-HPLC Determination of Raloxifene in Pharmaceuticl Tablets

2006 ◽  
Vol 3 (1) ◽  
pp. 60-64 ◽  
Author(s):  
P. Venkata Reddy ◽  
B. Sudha Rani ◽  
G. Srinu Babu ◽  
J. V. L. N. Seshagiri Rao
Keyword(s):  
Flow Rate ◽  
Retention Time ◽  
Mobile Phase ◽  
Dosage Forms ◽  
Hplc Method ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Pharmaceutical Dosage Forms ◽  
Rp Hplc

A reverse phase HPLC method is developed for the determination of Raloxifene in pharmaceutical dosage forms. Chromatography was carried out on an inertsil C18 column using a mixture of acetonitrile and phosphate buffer (30:70 v/v) as the mobile phase at a flow rate of 1 mL/min. Detection was carried out at 290 nm .The retention time of the drug was 10.609 min. The method produced linear responses in the concentration range of 0.5-200 µg/mL of Raloxifene. The method was found to be applicable for determination of the drug in tablets.

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