scholarly journals Monitoring of Remaining Thiophenic Compounds in Liquid Fuel Desulphurization Studies Using a Fast HPLC-UV Method

Separations ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 48
Author(s):  
Vasiliki Kapsali ◽  
Konstantinos Triantafyllidis ◽  
Eleni Deliyanni ◽  
Victoria Samanidou
Keyword(s):  
Liquid Fuel ◽  
Evaluation Studies ◽  
Gradient Elution ◽  
Sulfur Compounds ◽  
Regulatory Agencies ◽  
Monitoring Tool ◽  
Total Removal ◽  
Dibenzothiophene Sulfone ◽  
The Eu

Thiophenic compounds constitute a class of sulfur compounds derived by thiophene, containing at least one thiophenic ring. Their presence in fuels (crude oil, etc.) is important and can reach 3% m/m. The combustion of fuels leads to the formation of sulfur oxides a severe source of environmental pollution issues, such as acid rain with adverse effects both to humans and to the environment. To reduce such problems, the EU and other regulatory agencies worldwide set increasingly stringent regulations for sulfur content in fuels resulting in the necessity for intense desulphurization processes. However, most of these processes are inefficient in the total removal of sulfur compounds. Therefore, thiophenic compounds such as benzothiophenes and dibenzothiophenes are still present in heavier fractions of petroleum, therefore, their determination is of great importance. Until now, all HPLC methods applied in similar studies use gradient elution programs that may last more than 25 min with no validation results provided. To fill this gap, the aim of the present study was to develop and validate a simple and fast HPLC-UV method in order to be used as a useful monitoring tool in the evaluation studies of novel desulfurization technologies by means of simultaneous determination of dibenzothiophene (DBT) and 4,6-dimethyl-dibenzothiophene and dibenzothiophene sulfone in the desulfurization effluents.

scholarly journals Detection of olive oils authenticity by determination of their sterol content using LC/GC

2013 ◽  
Vol 19 (No. 3) ◽  
pp. 97-103 ◽  
Author(s):  
I. Bohačenko ◽  
Z. Kopicová
Keyword(s):  
Packed Column ◽  
Gradient Elution ◽  
Unsaponifiable Fraction ◽  
Virgin Olive Oils ◽  
Olive Oils ◽  
Modified Method ◽  
Commission Regulation ◽  
Preparative Lc ◽  
The Eu

The content of selected sterols as declared in the EU Commission Regulation was used to prove the authenticity of olive oils. A modified method using the preparative LC with silica gel packed column and gradient elution with three mixtures of hexane and diethyl ether was used to separate undesirable interfering compounds in the unsaponifiable fraction before the determination of sterols using GC. Model experiments based on the determination of D-7-stigmastenol and campesterol (addition of sunflower and soybean oils), or brassicasterol (addition of rapeseed oil) were used to verify that this method is capable of identifying adulteration of olive oils by additions of sunflower, soybean or rapeseed oils. An elevated content of these marker sterols, in comparison with their permitted contents, enables the identification of an addition of 5–10% of the above oils to the olive oil. This method was also used to evaluate the authenticity of five samples of olive oils from the SIAL exhibition (Paris) and ten samples of virgin olive oils obtained on thePrague markets. It was revealed that none of the samples showed the signs of adulteration.

Simultaneous Determination of Eight Potential Q-Markers in Zishen Tongguan Capsules Based on UHPLC-MS/MS

2020 ◽  
Vol 17 (1) ◽  
pp. 47-56
Author(s):  
Shun Liu ◽  
Xun Wang ◽  
Kaiping Zou ◽  
Wei Liu ◽  
Cunyu Li ◽  
...  
Keyword(s):  
Quality Control ◽  
Chinese Medicine ◽  
Simultaneous Determination ◽  
High Performance ◽  
Multiple Reaction Monitoring ◽  
Gradient Elution ◽  
Quality Markers ◽  
High Repeatability ◽  
Comprehensive Study

Background: Zishen Tongguan (ZSTG) capsules were prepared at the Affiliated Hospital of Nanjing University of Chinese Medicine and have been proven to be clinically effective for treating pyelonephritis and benign prostatic hyperplasia. However, the quality standards are not ideal; a comprehensive study of the “quality markers” (Q-markers), the chemicals inherent in traditional Chinese medicine and its preparations, has not been carried out. Experimental Methods: In this paper, a sensitive and specific ultra-high-performance liquid chromatographictandem mass spectrometry (UHPLC-MS/MS) method was developed for the simultaneous determination of eight potential Q-markers of ZSTG, including timosaponin A3, berberine, jatrorrhizine, phellodendrine, palmatine, mangiferin, neomangiferin, and timosaponin BII. A Kromasil 100-3.5 C18 column was used with a mobile phase of 0.2% formic acid with acetonitrile, and gradient elution at a flow rate of 0.2 mL/min was achieved in 13 minutes and used for separation. Detection was performed in positive/negative mode with multiple reaction monitoring (MRM). Results: The analytical method was validated in terms of the sensitivity, linearity, accuracy, precision, repeatability, stability and recovery. The method established here was successfully applied to study the potential Q-markers in 8 batches of commercial samples, which demonstrated its use in improving the quality control of ZSTG. Conclusion: The developed method had high repeatability and accuracy and was suitable for the simultaneous analysis of multiple Q-markers, which may provide a new basis for the comprehensive assessment and overall quality control of ZSTG.

Simultaneous Determination of Methocarbamol and Paracetamol in the Presence of Three Related Substances by Ultra Performance Liquid Chromatography

2019 ◽  
Vol 15 (5) ◽  
pp. 505-510
Author(s):  
Yanjuan Zheng ◽  
Qiushi Peng ◽  
Rui Dong ◽  
Tingyu Chen ◽  
Yi Bao ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Pharmaceutical Preparations ◽  
Gradient Elution ◽  
Ultra Performance Liquid Chromatography ◽  
Related Substances ◽  
Bulk Powder ◽  
Highly Sensitive ◽  
Optimal Protocol ◽  
Acquity Uplc

Introduction: A rapid, and accurate Ultra Performance Liquid Chromatography (UPLC) method was developed to simultaneously analyze Methocarbamol, Paracetamol and the related substances Materials and Methods: Waters ACQUITY UPLC® BEH Phenyl C18 column was used in conjunction with UV detection at 225nm. Gradient elution with 0.05M, pH 6 phosphate buffer and acetonitrile flow at 0.3mL /min rate were used to separate the substances. The retention times for 4-Aminopheno, Paracetamol, Guaifenesin, Methocarbamol, and 4-Chloroacetanilide were 1.319 minute, 2.224 minute, 4.467 minute, 4.769 minute and 5.433 minute respectively. The concentration was linear in the range of 2-100 µg/ml for Methocarbamol, and 1-100 µg/mL for Paracetamol. The percentage recoveries were between 99.28±1.23% to 100.57±0.99% for Methocarbamol, and between 99.08±1.23% to 101.23±1.39% for Paracetamol. Results and Discussion: The validated optimal protocol is robust and accurate for simultaneous analysis of Methocarbamol, Paracetamol and the related substances, applicable for bulk powder as well as pharmaceutical formulation. Conclusion: In this paper, a highly sensitive, accurate, and precise UPLC method with UV-Vis detection was developed and validated for quality control of MET and PAR in bulk as well as in pharmaceutical preparations.

Simultaneous Determination of Alogliptin, Linagliptin, Saxagliptin, and Sitagliptin in Bulk Drug and Formulation by UPLC Q-TOF-MS

2020 ◽  
Vol 17 (1) ◽  
pp. 95-105
Author(s):  
Ramji Rathod ◽  
Faraat Ali ◽  
Amrish Chandra ◽  
Robin Kumar ◽  
Meenakshi Dahiya ◽  
...  
Keyword(s):  
Internal Standard ◽  
Gradient Elution ◽  
Ultra Performance Liquid Chromatography ◽  
Pharmaceutical Dosage Forms ◽  
Sensitivity And Selectivity ◽  
The Mean ◽  
Bulk Drug ◽  
Positive Ion ◽  
Higher Sensitivity

Background: A simple and sensitive Ultra Performance Liquid Chromatography-Mass Spectrometry method was developed and validated to measure the concentrations of Alogliptin (ALO), Linagliptin (LIN), Saxagliptin (SAX), and Sitagliptin (SIT) using Pioglitazone (PIO) as an internal standard. Methods: Chromatographic separation of six gliptins was achieved on a C-18 column (100×2.1 mm, 2.7 μm) using a mobile phase consisting of formic acid in water, 0.1%v/v: acetonitrile in gradient elution. Electrospray ionization (ESI) source was operated in the positive ion mode. Targeted MS/MS mode on a QTOF MS was used to quantify the drug utilizing the transitions of 340.1(m/z), 473.2 (m/z), 316.2 (m/z), 408.1 (m/z), and 357.1 (m/z) for ALO, LIN, SAX, SIT and PIO respectively. Results: As per ICH Q2R1 guidelines, a detailed validation of the method was carried out and the standard curves were found to be linear over the concentration ranges of 1516.0-4548.1 ng mL-1, 519.8- 1559.4 ng mL-1, 1531.4-4594.3 ng mL-1and 1519.6-4558.8 ng mL-1 for ALO, LIN, SAX and SIT respectively. Precision and accuracy results were within the acceptable limits. The mean recovery was found to be 98.8 _ 0.76 % (GEM), 102.2 _ 1.59 % (LIN), 95.3 _ 2.74 % (SAX) and 99.2 _ 1.75 % (SIT) respectively. Conclusions: The optimized validated UPLC QTOF-MS/MS method offered the advantage of shorter analytical times and higher sensitivity and selectivity. The optimized method is suitable for application in quantitative analysis of pharmaceutical dosage forms for QC laboratory.

Quantitative Analysis of 5-Hydroxymethylfurfural in Linezolid Injection by High Performance Liquid Chromatography

2020 ◽  
Vol 16 (8) ◽  
pp. 1059-1067
Author(s):  
Jéssica Maurício Batista ◽  
Christian Fernandes
Keyword(s):  
High Performance ◽  
Potassium Phosphate ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Official Method ◽  
Ph Variation ◽  
Drug Products ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Background: Linezolid is a synthetic broad-spectrum antibacterial belonging to the class of oxazolidinones. Linezolid for intravenous infusion is isotonized with dextrose. In acidic environment, the dehydration of dextrose produces furan derivatives, 5-hydroxymethylfurfural (5-HMF) being the main one. The determination of this degradation product is of fundamental importance, since there is evidence it is cytotoxic, genotoxic, mutagenic and carcinogenic. However, there is no official method for the determination of 5-HMF in drug products. Objective: The aim of this study was to develop and validate a high performance liquid chromatographic method to quantify 5-HMF in injection of linezolid. Methods: The chromatographic separation, after optimization, was performed on C18 (150 x 4.6 mm, 5 μm) column. Mobile phase was composed of 14 mM potassium phosphate buffer pH 3.0 ([H+] = 1.0 x 10-3) and methanol in gradient elution at 1.0 mL min-1. The injection volume was 10 μL and detection was performed at 285 nm. Results: The method was optimized and validated, showing selectivity, linearity in the range from 0.075 to 9.0 μg mL-1, precision (RSD ≤ 2.0%), accuracy (mean recovery of 100.07%) and robustness for temperature and pH variation. Conclusion: The method was shown to be adequate to determine 5-HMF in injection containing linezolid in routine analysis.

Simultaneous Determination of Six Components in Jingzhiguanxin Tablet by High-Performance Liquid Chromatography

2019 ◽  
Vol 15 (2) ◽  
pp. 130-137
Author(s):  
Hui Jiang ◽  
Lianhao Fu ◽  
Yu Wang ◽  
Shaozhi Wang ◽  
Xiaoxu Zhang ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
High Performance ◽  
Gradient Elution ◽  
Tanshinone Iia ◽  
Array Detector ◽  
Control Analysis ◽  
Active Components ◽  
Quality Control Analysis

Background: Jingzhiguanxin (JZGX) tablet, a traditional Chinese prescription, is commonly used for treating coronary heart disease and angina pectoris in the clinic. There are six active components (Danshensu (DSS), Protocatechuic aldehyde (PD), Paeoniflorin (PF), Ferulic acid (FA), Salvianolic acid B (Sal B) and Tanshinone IIA (TA)) in JZGX tablet. </P><P> Objective: In this paper, a simple and reliable method was used for simultaneous determining the six active components by high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). Methods: These six active components were separated on an Agilent Zorbax Eclipse XDB-C18 column (150 mmx4.6 mm, 5 µm) at 30 °C. Acetonitrile (A), methanol (B) and 0.5% H3PO4 aqueous solution (C) were used as mobile phase for gradient elution. The flow rate was 1 mL/min and the detection wavelengths were set at 280 nm for DSS, PD and Sal B, 230 nm for PF, 320 nm for FA and 270 nm for TA, respectively. Results: All of the six components showed good linearity regressions (r2≥0.9997) in the detected concentration range. The recovery rates and coefficient of variation (CV) for all analytes were 98.66%- 100.18% and 0.75%-1.89%, respectively. This method was successfully applied to simultaneously determine the six components in JZGX tablet from different batches and manufacturers. Conclusion: The validated method can be used in routine quality control analysis of JZGX tablet without any interference.

Simultaneous Determination of Imatinib and N-Desmethyl Imatinib in Rat Plasma and Tissues Using LC-MS/MS

2019 ◽  
Vol 15 (2) ◽  
pp. 121-129
Author(s):  
Zhi Rao ◽  
Bo-xia Li ◽  
Yong-Wen Jin ◽  
Wen-Kou ◽  
Yan-rong Ma ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Oral Administration ◽  
Parent Drug ◽  
Gradient Elution ◽  
Biological Tissues ◽  
Rat Plasma ◽  
Running Water ◽  
Liver And Kidney ◽  
The Brain

Background: Imatinib (IM) is a chemotherapy medication metabolized by CYP3A4 to Ndesmethyl imatinib (NDI), which shows similar pharmacologic activity to the parent drug. Although methods for determination of IM and/or NDI have been developed extensively, only few observations have been addressed to simultaneously determine IM and NDI in biological tissues such as liver, kidney, heart, brain and bone marrow. Methods: A validated LC-MS/MS method was developed for the quantitative determination of imatinib (IM) and N-desmethyl imatinib (NDI) from rat plasma, bone marrow, brain, heart, liver and kidney. The plasma samples were prepared by protein precipitation, and then the separation of the analytes was achieved using an Agilent Zorbax Eclipse Plus C18 column (4.6 × 100 mm, 3.5 µm) with gradient elution running water (A) and methanol (B). Mass spectrometric detection was achieved by a triplequadrupole mass spectrometer equipped with an electrospray source interface in positive ionization mode. Results: This method was used to investigate the pharmacokinetics and the tissue distributions in rats following oral administration of 25 mg/kg of IM. The pharmacokinetic profiles suggested that IM and NDI are disappeared faster in rats than human, and the tissue distribution results showed that IM and NDI had good tissue penetration and distribution, except for the brain. This is the first report about the large penetrations of IM and NDI in rat bone marrow. Conclusion: The method demonstrated good sensitivity, accuracy, precision and recovery in assays of IM and NDI in rats. The described assay was successfully applied for the evaluation of pharmacokinetics and distribution in the brain, heart, liver, kidney and bone marrow of IM and NDI after a single oral administration of IM to rats.

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