scholarly journals Determination of Genotoxic Azide Impurity in Cilostazol API by Ion Chromatography with Matrix Elimination

Separations ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 162
Author(s):  
Boglárka Páll ◽  
Zsuzsa Gyenge ◽  
Róbert Kormány ◽  
Krisztián Horváth
Keyword(s):  
Sample Preparation ◽  
Ion Chromatography ◽  
Sodium Azide ◽  
Limit Of Detection ◽  
Active Pharmaceutical Ingredient ◽  
Liquid Extraction ◽  
Limit Of Quantification ◽  
Positive Effects ◽  
Liquid Liquid Extraction

Cilostazol is a commonly used active pharmaceutical ingredient (API) to treat and reduce the symptoms of intermittent claudication in peripheral vascular disease. Recently, it was found to be a potential medicine in the effective treatment of COVID-19. In addition to the positive effects of this API, genotoxic sodium azide is used in the synthesis of cilostazol that can appear in the API. In this work, a method was developed for the determination of sodium azide (as azide anion) in cilostazol API at 7.5 ppm limit level by using ion chromatography (IC) and liquid–liquid extraction (LLE) sample preparation. The liquid–liquid extraction allows the application of high sample concentrations. Because of the low limit concentration (7.5 ppm), 500 mg sample was dissolved in 5 mL solvent. By using LLE for sample preparation, the huge amount of cilostazol was omitted and column overload was avoided. The developed method was validated in accordance with the relevant guidelines. Specificity, accuracy, precision, limit of detection and limit of quantification parameters were evaluated. The calculated limit of detection was 0.52 ppm (S/N:3) and the limit of quantification was 1.73 ppm (S/N:10) for sodium azide. The recovery of the sodium azide was 102.4% and the prepared solutions were stable in the sample holder for 24 h.

Determination of Potential Genotoxic Impurity, 5-Amino-2-Chloropyridine, in Active Pharmaceutical Ingredient Using the HPLC-UV System

2020 ◽  
Author(s):  
Murat Soyseven ◽  
Rüstem Keçili ◽  
Hassan Y Aboul-Enein ◽  
Göksel Arli
Keyword(s):  
Analytical Method ◽  
High Performance ◽  
Orthophosphoric Acid ◽  
Limit Of Detection ◽  
Detection System ◽  
Active Pharmaceutical Ingredient ◽  
Limit Of Quantification ◽  
Column Temperature ◽  
Water Ph

Abstract A novel analytical method, based on high-performance liquid chromatography with a UV (HPLC-UV) detection system for the sensitive detection of a genotoxic impurity (GTI) 5-amino-2-chloropyridine (5A2Cl) in a model active pharmaceutical ingredient (API) tenoxicam (TNX), has been developed and validated. The HPLC-UV method was used for the determination of GTI 5A2Cl in API TNX. The compounds were separated using a mobile phase composed of water (pH 3 adjusted with orthophosphoric acid): MeOH, (50:50: v/v) on a C18 column (150 × 4.6 mm i.d., 2.7 μm) at a flow rate of 0.7 mL min−1. Detection was carried out in the 254 nm wavelength. Column temperature was maintained at 40°C during the analyses and 10 μL volume was injected into the HPLC-UV system. The method was validated in the range of 1–40 μg mL−1. The obtained calibration curves for the GTI compound was found linear with equation, y = 40766x − 1125,6 (R2 = 0.999). The developed analytical method toward the target compounds was accurate, and the achieved limit of detection and limit of quantification values for the target compound 5A2Cl were 0.015 and 0.048 μg mL−1, respectively. The recovery values were calculated and found to be between 98.80 and 100.03%. The developed RP-HPLC-UV analytical method in this research is accurate, precise, rapid, simple and appropriate for the sensitive analysis of target GTI 5A2Cl in model API TNX.

scholarly journals Comparison of two sample preparation procedures for HPLC determination of ochratoxin A

2009 ◽  
Vol 61 (4) ◽  
pp. 639-644 ◽  
Author(s):  
Gorica Vukovic ◽  
Snezana Pavlovic ◽  
M.S. Ristic
Keyword(s):  
Sample Preparation ◽  
Phosphoric Acid ◽  
Ochratoxin A ◽  
Chromatographic Determination ◽  
Liquid Extraction ◽  
Immunoaffinity Column ◽  
Maize Flour ◽  
Liquid Liquid Extraction ◽  
Immunoaffinity Columns

In preparation of samples for chromatographic determination of ochratoxin A, two types of columns were used for sample cleanup (SPE and immunoaffinity columns). The first method consisted of liquid-liquid extraction with a mixture of chloroform and phosphoric acid, followed by ion-exchange cleanup on Waters Oasis MAX columns. The sec?ond method consisted of extraction with a mixture of water and methanol, followed by LCTech OtaCLEAN immunoaf?finity column cleanup. Recoveries of the methods were determined at three levels in three repetitions for maize flour, and they were 84% (%RSD = 19.2) for the first method of sample preparation and 101% (%RSD = 2.2) for the second method. Values of LOQ for OTA were 0.25 and 1.00 ?g/kg for the IAC and SPE clean-up procedures, respectively. Both methods comply with present regulations, but the MAX sample clean-up procedure should be used as an alternative, since the immunoaffinity column clean-up procedure is characterized by better reproducibility, accuracy, and efficiency.

Development and Validation of a Method for Quantification of 28 Psychotropic Drugs in Postmortem Blood Samples by Modified Micro-QuEChERS and LC–MS-MS

2020 ◽  
Author(s):  
Taís B Rodrigues ◽  
Damila R Morais ◽  
Victor A P Gianvecchio ◽  
Elvis M Aquino ◽  
Ricardo L Cunha ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Forensic Toxicology ◽  
Sample Volume ◽  
Weighting Factor ◽  
Liquid Extraction ◽  
Analytical Toxicology ◽  
Limit Of Quantification ◽  
Liquid Liquid Extraction ◽  
Postmortem Blood ◽  
Development And Validation

Abstract The development of new sample preparation alternatives in analytical toxicology leading to quick, effective, automated and environmentally friendly procedures is growing in importance. One of these alternatives is the QuEChERS, originally developed for the analysis of pesticide residues, producing cleaner extracts than liquid–liquid extraction, and easier separation of aqueous and organic phases. However, there are few published studies on the miniaturization of this technique for forensic toxicology, especially in postmortem analysis. We developed and validated a modified micro-QuEChERS and LC–MS-MS assay to quantify 16 antidepressants, 7 antipsychotics and 3 metabolites and semi-quantify norfluoxetine and norsertraline in postmortem blood. The calibration curve was linear from 1 to 500 ng/mL, achieved an r > 0.99, with all standards quantifying within ±15% of target except ±20% at the limit of quantification of 1 ng/mL for 26 substances. The F test was applied to evaluate if the variance between replicates remained constant for all calibrators. Six weighting factors were analyzed (1/x, 1/x2, 1/x0,5, 1/y, 1/y2 and 1/y0,5), with the weighting factor with the lowest sum of residual regression errors (1/x2) selected. No endogenous or exogenous interferences were observed. Method imprecision and bias were <19.0% and 19.7%, respectively. Advantages of this method include a low sample volume of 100 µL, simple but effective sample preparation and a rapid 8.5-min run time. The validated analytical method was successfully applied to the analysis of 100 authentic postmortem samples.

scholarly journals Matrix-Induced Sugaring-Out: A Simple and Rapid Sample Preparation Method for the Determination of Neonicotinoid Pesticides in Honey

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2761 ◽  
Author(s):  
Wenbin Chen ◽  
Siyuan Wu ◽  
Jianing Zhang ◽  
Fengjie Yu ◽  
Jianbo Hou ◽  
...  
Keyword(s):  
Phase Separation ◽  
Sample Preparation ◽  
Preparation Method ◽  
Liquid Extraction ◽  
Subzero Temperature ◽  
Water Mixture ◽  
Sample Preparation Method ◽  
Liquid Liquid Extraction ◽  
Neonicotinoid Pesticides

In the present work, we developed a simple and rapid sample preparation method for the determination of neonicotinoid pesticides in honey based on the matrix-induced sugaring-out. Since there is a high concentration of sugars in the honey matrix, the honey samples were mixed directly with acetonitrile (ACN)-water mixture to trigger the phase separation. Analytes were extracted into the upper ACN phase without additional phase separation agents and injected into the HPLC system for the analysis. Parameters of this matrix-induced sugaring-out method were systematically investigated. The optimal protocol involves 2 g honey mixed with 4 mL ACN-water mixture (v/v, 60:40). In addition, this simple sample preparation method was compared with two other ACN-water-based homogenous liquid-liquid extraction methods, including salting-out assisted liquid-liquid extraction and subzero-temperature assisted liquid-liquid extraction. The present method was fully validated, the obtained limits of detection (LODs) and limits of quantification (LOQs) were from 21 to 27 and 70 to 90 μg/kg, respectively. Average recoveries at three spiked levels were in the range of 91.49% to 97.73%. Precision expressed as relative standard deviations (RSDs) in the inter-day and intra-day analysis were all lower than 5%. Finally, the developed method was applied for the analysis of eight honey samples, results showed that none of the target neonicotinoid residues were detected.

Determination of hydrazine at Ontario nuclear power plants

2015 ◽  
Vol 7 (23) ◽  
pp. 9825-9834 ◽  
Author(s):  
Slobodan V. Jovanovic ◽  
Thomas Zakharov ◽  
Hemendra Mulye ◽  
Duck Kim ◽  
Kelly-Anne Fagan
Keyword(s):  
Ion Chromatography ◽  
Water Samples ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Limit Of Detection ◽  
Limit Of Quantification ◽  
Amperometric Detector ◽  
Sensitive Method

In this study, we developed and validated a sensitive method for the determination of hydrazine in water samples using ion chromatography coupled with an amperometric detector (limit of detection (LOD) = 0.02 μg L−1 and limit of quantification (LOQ) = 0.1 μg L−1).

scholarly journals Complex Formation in a Liquid-Liquid Extraction System Containing Cobalt(II), 4-(2-Pyridylazo)resorcinol, and Nitron

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Petya Vassileva Racheva ◽  
Kiril Blazhev Gavazov ◽  
Vanya Dimitrova Lekova ◽  
Atanas Nikolov Dimitrov
Keyword(s):  
Complex Formation ◽  
Limit Of Detection ◽  
Equilibrium Constants ◽  
Ion Association ◽  
Molar Absorptivity ◽  
Liquid Extraction ◽  
Optimum Conditions ◽  
Limit Of Quantification ◽  
Liquid Liquid Extraction ◽  
Experimental Parameters

Complex formation and liquid-liquid extraction were studied in a system containing cobalt(II), 4-(2-pyridylazo)resorcinol (PAR), 1,4-diphenyl-3-(phenylamino)-1H-1,2,4-triazole (Nitron, Nt), water, and chloroform. The effect of some experimental parameters (pH, shaking time, concentration of PAR, and concentration of Nt) was systematically investigated, and the optimum conditions for cobalt extraction as an ion-association complex, (NtH+)[Co3+(PAR)2], were found. The following key equilibrium constants were calculated: constant of association (Log β=4.77±0.06), constant of distribution (LogKD=1.34±0.01), and constant of extraction (LogKex=6.11±0.07). Beer’s law was obeyed for Co concentrations up to 1.7 μg mL−1 with a molar absorptivity of 6.0×104 L mol−1 cm−1 at λmax=520 nm. Some additional characteristics, such as limit of detection, limit of quantification, and Sandell’s sensitivity, were estimated as well.

scholarly journals Determination of Sodium Azide in Beverages by Ion Chromatography

2000 ◽  
Vol 83 (6) ◽  
pp. 1410-1414 ◽  
Author(s):  
Harumi Oshima ◽  
Eiji Ueno ◽  
Isao Saito ◽  
Hiroshi Matsumoto
Keyword(s):  
Detection Limit ◽  
Sample Preparation ◽  
Sodium Hydroxide ◽  
Ion Chromatography ◽  
Sodium Azide ◽  
Convenient Method ◽  
Sodium Hydroxide Solution ◽  
Hydrazoic Acid ◽  
Suppressed Conductivity Detection

Abstract A convenient method for determination of sodium azide in beverages using ion chromatography is described. This method combines the specificity for azide with a simple sample preparation using a bubble and trap apparatus that removes any interferences. Sodium azide in a sample was acidified, and the azide was converted to the volatile hydrazoic acid, which was trapped in 2.5mM sodium hydroxide solution. Determination was performed by isocratic ion chromatography using suppressed conductivity detection. Calibration curves were linear for 0.5 to 20 μg/mL sodium azide and the detection limit was 0.05 μg/mL. Recoveries of sodium azide from spiked samples (10.0 μg/g) were more than 82.6%. The method was then used to analyze various beverages.

scholarly journals Aqueous Two-Phase System–Ion Chromatography for Determination of Thiocyanate in Raw Milk

Separations ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 212
Author(s):  
Bin Jiang ◽  
Shaojing Zhong ◽  
Hongliang Yu ◽  
Peifeng Chen ◽  
Baoyun Li ◽  
...  
Keyword(s):  
Ion Chromatography ◽  
Limit Of Detection ◽  
Raw Milk ◽  
Enrichment Ratio ◽  
Phase System ◽  
Limit Of Quantification ◽  
Two Phase ◽  
Aqueous Two Phase System ◽  
Pre Treatment

Thiocyanate could effectively inhibit bacteria in milk and extend the shelf life of milk. However, excessive addition will lead to health risks. Therefore, the determination of thiocyanate in raw milk has received a lot of attention, but the determination could be interfered with by other components in raw milk and the pre-treatment of raw milk is complex. In this study, a new pretreatment method combined with ion chromatography (IC) for rapid and sensitive determination of thiocyanate is proposed. An acetonitrile/(NH4)2SO4 aqueous two-phase system (ATPS) was developed for the separation and enrichment of thiocyanate in raw milk. Response surface methodology was performed to optimize the extraction conditions and an efficient pretreatment were obtained using ATPS composed of 42% acetonitrile (w/w) and 16% (NH4)2SO4 (w/w), with the pH 4.7, and the recovery of thiocyanate reached 107.24 ± 0.5%, and the enrichment ratio was 10.74 ± 0.03. IC was used to establish a thiocyanate enrichment method. The linear range was from 0.05 to 15 mg/L and R2 = 0.998, the limit of detection (LOD) was 0.2 μg/L, the limit of quantification (LQD) was 0.6 μg/L. Hence, it is feasible to combine ATPS with IC for the enrichment and determination of thiocyanate in raw milk.

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