scholarly journals Liquid Chromatography Analysis of Reactive Oxoammonium Cations

2021 ◽  
Author(s):  
Philip Rohland ◽  
Kristin Schreyer ◽  
Rene Burges ◽  
Nicole Fritz ◽  
Martin D. Hager ◽  
...  

AbstractThis study presents the first liquid chromatography method for the quantitative and qualitative analysis of highly reactive oxoammonium cations based on a simple derivatization reaction. Rapid 1,2-electrophilic addition reactions with olefins were used to transform these reactive species into analyzable derivates. Three model substances were chosen to represent each of the main application fields of oxoammonium cations and to demonstrate the versatility of the method. The measuring protocol was validated according to the ICH and USP guidelines. The method revealed an excellent linearity (R2 = 0.9980–0.9990) with a low limit of detection (0.16–0.14 mmol L−1) and a low limit of quantification (0.55–0.43 mmol L−1). The protocol was finally used to determine the oxoammonium cations in the presence of their corresponding radical, showing a robustness against impurity concentration of up to approx. 30%.

2013 ◽  
Vol 57 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Anna Gajda ◽  
Andrzej Posyniak ◽  
Andrzej Bober ◽  
Tomasz Błądek ◽  
Jan Żmudzki

Summary A liquid chromatography method with UV detection for determination of oxytetracycline (OTC) in honey has been developed. The samples were extracted with the solution of oxalic acid. The clean-up procedure was performed by solid phase extraction (SPE) using polymeric Strata X and carboxylic acid cartridges. Chromatographic separation was carried out on the Luna C8 analytical column with mobile phase consisting of acetonitrile-0.02 M oxalic acid. The method has been successfully validated according to the requirements of the European Decision 2002/657/EC and this method is used in routine control of oxytetracycline in honey samples. The limit of detection (LOD) and limit of quantification (LOQ) of the presented method were 10 and 12.5 μg/kg, respectively. The developed method has also been verified in quantitative determination of oxytetracycline residues in honey after experimental treatment with this product in bee colonies.


Author(s):  
BYRAN GOWRAMMA ◽  
SUBRAMANIYAN NAIYANAR MEYYANATHAN ◽  
BASAWAN BABU ◽  
NAGAPPAN KRISHNAVENI

Objective: In the present study, an isocratic chiral reverse-phase high-performance liquid chromatography method was developed and the resolution of the drug and complete separation from its degradation products were successfully achieved. Methods: An isocratic method developed with a Phenomenex Lux 5 μ Cellulose 1 (150 mm×4.6 mm i.d., 5 μ) using UV detector at wavelength of 220 nm, with a mobile phase consisting of methanol:0.1% diethylamine (60:40% v/v) and a flow rate of 1 ml/min. The drug was subjected to alkaline, acidic, neutral, oxidative, and photolytic to apply stress conditions. The stressed samples were analyzed by the proposed method. Results: The described method was linear over the range of 3–7 μg/ml for R-enantiomer and 9–21 μg/ml of S-enantiomer, respectively. The limit of detection and limit of quantification of R and S enantiomers were found to be 0.56 μg/ml and 0.18 μg/ml, respectively. Conclusion: The method provides good sensitivity and excellent precision and reproducibility. The developed method can be applied in the quality control of drug products.


Author(s):  
Poornima K. ◽  
Channabasavaraj Kp.

<p><strong>Objective: </strong>A new, rapid, selective, precise, accurate and economical, isocratic, reverse phase high-performance liquid chromatography method has been developed for simultaneous estimation of loperamide hydrochloride and tinidazole in bulk and in tablet formulations.</p><p><strong>Methods: </strong>The separation was achieved by using Lithosphere RP C-18, (250 x 4.6 mm, 5 µm) end capped column with a mobile phase containing sodium-1-octane sulfonate buffer: methanol: acetonitrile (40:30:30%v/v/v) pH adjusted to 4.0 (using dilute orthophosphoric acid). The flow rate was 1.0 ml/m and column effluent was monitored at 224 nm. The method was validated as per international conference on chemical harmonization (ICH) guidelines.</p><p><strong>Results</strong>:<strong> </strong>Tinidazole and loperamide hydrochloride were eluted at about 3.1 and 5.4 min respectively, indicating the shorter analysis time. The proposed method was found to be accurate, precise and reproducible. The linearity was established in the concentration range of 10-50 µg/ml. Limit of detection (LOD) and Limit of quantification (LOQ) was found to be 0.001 µg/ml and 0.003 µg/ml for loperamide hydrochloride and 0.01 µg/ml and 0.03 µg/ml for tinidazole.</p><p><strong>Conclusion: </strong>This method can be used for routine analysis of formulations containing any of the above drugs or combinations without any alteration in the chromatographic conditions.</p>


Author(s):  
Revathi Naga Lakshmi Ponnuri ◽  
Prahlad Pragallapati ◽  
Mastanamma Sk ◽  
Ravindra N ◽  
Venkata Basaveswara Rao Mandava ◽  
...  

ABSTRACTObjective: The objective of present work was to develop and validate a simple, fast, precise, selective, and accurate reverse phase high-performanceliquid chromatography method for the simultaneous determination of Clindamycine, Metronidazole and Clotrimazole in a pharmaceutical dosageform.Methods: The separation of these three drugs was achieved on ODS 250×4.6 mm, 5 mm C column. Mobile phase containing 0.1% ortho phosphoricacid buffer and acetonitrile in the ratio of 55:45 v/v was pumped through column at a flow rate of 1 ml/minute. Temperature was maintained at 30°Cand ultraviolet detection at 238 nm.18Results: The retention times were observed to be 2.591, 3.584, and 4.221 minutes for Clindamycine, Metronidazole, and Clotrimazole, respectively.Linearity was found to be 25-150 μg/ml Clindamycine, Metronidazole, and Clotrimazole, respectively. The method was statistically validated forlinearity, recovery, the limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision. The stress testing of the drugs individually andtheir mixture are carried out under acidic, alkaline, oxidation, photostability, and thermal degradation conditions and its degradation products arewell resolved from the analyte peaks.Conclusion: This method was successfully validated for accuracy, precision, and linearity, LOD, and LOQ.Keywords: Clindamycine, Metronidazole, Clotrimazole, Reverse phase-high performance liquid chromatography, Simultaneous determination,Degradation studies.


2012 ◽  
Vol 9 (3) ◽  
pp. 1449-1456
Author(s):  
B. V. Suma ◽  
K. Kannan ◽  
V. Madhavan ◽  
Chandini R. Nayar

A new simple, specific, precise and accurate revere phase liquid chromatography method has been developed for estimation of atorvastatin calcium (AST) and ASPIRIN (ASP) simultaneously in a combined capsule dosage forms. The chromatographic separation was achieved on a 5 – micron C 18 column (250x 4.6mm) using a mobile phase consisting of a mixture of Acetonitrile: Ammonium Acetate buffer 0.02M (68:32) pH 4.5. The flow rate was maintained at 0.8 ml/min. The detection of the constituents was done using UV detector at 245 nm for AST and ASP. The retention time of AST and ASP were found be 4.5915 ± 0.0031 min and 3.282 ±0.0024 min respectively. The developed method was validated for accuracy, linearity, precision, limit of detection (LOD) and limit of quantification (LOQ) and robustness as per the ICH guidelines.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Iqbal Ahmad ◽  
Syed Haider Abbas ◽  
Zubair Anwar ◽  
Muhammad Ali Sheraz ◽  
Sofia Ahmed ◽  
...  

A stability-indicating photochemical method has been developed for the assay of thiamine (TH) salts in aqueous solution and in fresh and aged vitamin preparations. It is based on the photooxidation of TH by UV irradiation to form thiochrome (TC) in alkaline solution. The TC : TH ratio under controlled conditions of light intensity, temperature, pH, exposure time, and irradiation distance is constant and can be used to determine the concentration of UV irradiated TH solutions. TC, on extraction with isobutanol from the photodegraded solution of TH, has been determined by the UV spectrophotometric method at 370 nm. It exhibits a high intensity of absorption in the UV region that can be used for the assay of even low concentrations of TH. Under optimum conditions, Beer’s law is obeyed in the concentration range of 0.20–2.00 mg/100 ml (R2 = 09998). The limit of detection (LOD) and limit of quantification (LOQ) are 0.0076 and 0.0231 mg/100 ml, respectively. The method has been validated and applied to aqueous solutions and vitamin preparations. The results have statistically been compared with the United States Pharmacopeia liquid chromatography method. It has been found that there is no significant difference between the two methods at 95% confidence level.


2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Ahmed Salem Sebaei ◽  
Ahmed M. Gomaa ◽  
A. A. El-Zwahry ◽  
E. A. Emara

Formaldehyde is one of the most dangerous chemical compounds affecting the human health; exposure to it from food may occur naturally or by intentional addition. In this study a high performance liquid chromatography method for determination of formaldehyde in dairy products was described. The dairy samples were reacted and extracted with a warmed organic solvent in the presence of derivatizing agent 2,4-dinitrophenylhydrazine (DNPH) and formaldehyde; the mixture was centrifuged and followed by diode array detection. The method is validated and gives average recovery of formaldehyde at the three different levels 0.1, 5.0, and 10.0 mg/kg varied between 89% and 96%. The method is linear from the limit of quantification 0.1 mg/kg up to 10 mg/kg levels. This method is intended for formaldehyde analyses in dairy products simply with stable derivatization, minimum residue loss, excellent recovery, and accurate results with a sensitive limit of detection 0.01 mg/kg. 90 dairy samples from milk, cheese, and yogurt were investigated from seven Egyptian governorates and all samples were free from formaldehyde.


Author(s):  
Gudipally. Mounika ◽  
K. Bhavya Sri ◽  
R. Swethasri ◽  
M. Sumakanth

To develop an accurate, precise, specific high performance liquid chromatography method for quantification of Canagliflozin in bulk and dosage forms. A C18 column (250mm X 4.6mm; 5μm phenomenex) was used with mobile phase containing Acetonitrile-0.1% sodium acetate buffer (pH-4.6), (20:80) in isocratic mode. The flow rate maintained was 1.0ml/min and the U.V detector was operated at 291nm. The retention time of Canagliflozin was 3.307min and showed a good linearity in concentration range of 2-14μg/ml with correlation coefficient of 0.999. The average percent recovery was found to be 99.98%. The developed method follows validation parameters such as system suitability, linearity, precision, accuracy, limit of detection and limit of quantification and robustness as per ICH guidelinesQ2(R1). The proposed method was found to provide faster retention time with sharp resolution with linearity at a lowest concentration as compared to previous methods and this method is validated as per International conference on harmonization guidelines and successfully applied for bulk and pharmaceutical dosage form.


INDIAN DRUGS ◽  
2019 ◽  
Vol 56 (09) ◽  
pp. 68-73
Author(s):  
K Vijaya Sri ◽  
M. Shiva Kumar ◽  
M. A. Madhuri ◽  
Suresha K. ◽  

In this study, a high-performance liquid chromatographic method (HPLC) was developed, validated and applied for the determination of raltegravir in biological sample like saliva. Liquid- liquid extraction was performed for isolation of the drug and elimination of saliva interferences. Samples of saliva was extracted with 50µL of ortho phosphoric acid and 3ml of methanol was added and spiked with raltegravir. The chromatographic separation was performed on Agilent Eclipse C18 (100 mm × 4.6 mm, 3.5µm) column, by using 80:20 v/v acetonitrile: water as a mobile phase under isocratic conditions at a flow rate of 1.0 mL/min for UV detection at 240 nm. Retention time of raltegravir was found to be 1.030 min. Linearity was found to be in the range of 25-1000 ng/mL with regression equation y = 13864x + 40495 and correlation coefficient 0.999. The low % RSD value indicates the method is accurate and precise. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.76 and 2.28 ng/mL, respectively. It can be concluded that this validated HPLC method is easy, precise, accurate, sensitive and selective for determination of raltegravir in saliva.


2010 ◽  
Vol 54 (8) ◽  
pp. 3408-3413 ◽  
Author(s):  
Lorena Baietto ◽  
Antonio D'Avolio ◽  
Giusi Ventimiglia ◽  
Francesco Giuseppe De Rosa ◽  
Marco Siccardi ◽  
...  

ABSTRACT We have developed and validated a high-performance liquid chromatography method coupled with a mass detector to quantify itraconazole, voriconazole, and posaconazole using quinoxaline as the internal standard. The method involves protein precipitation with acetonitrile. Mean accuracy (percent deviation from the true value) and precision (relative standard deviation percentage) were less than 15%. Mean recovery was more than 80% for all drugs quantified. The lower limit of quantification was 0.031 μg/ml for itraconazole and posaconazole and 0.039 μg/ml for voriconazole. The calibration range tested was from 0.031 to 8 μg/ml for itraconazole and posaconazole and from 0.039 to 10 μg/ml for voriconazole.


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