scholarly journals Ergosterol content in selected grasses on the end of vegetation period

2007 ◽  
Vol 55 (4) ◽  
pp. 9-14 ◽  
Author(s):  
Vlastimil Dohnal ◽  
Ilona Kaderová ◽  
Alena Ježková ◽  
Jiří Skládanka
Keyword(s):  
Festuca Arundinacea ◽  
Lolium Multiflorum ◽  
Dactylis Glomerata ◽  
Vegetation Period ◽  
Ultraviolet Region ◽  
Forage Crops ◽  
Liquid Chromatographic Method ◽  
Arrhenatherum Elatius ◽  
Liquid Chromatographic

Ergosterol is a natural compound with steroidic structure produced mainly by fungi. Due to this, it is considered as a marker of fungal spoilage. In this work, the content of ergosterol was monitored in samples of three forage crops (Festuca arundinacea x Lolium multiflorum, Dactylis glomerata, Arrhenatherum elatius) during period October–December 2005 and different term of summer harvesting (June or July). There were adapted and applied liquid chromatographic method with fotometric detection in ultraviolet region for determination of this compound. It was found, that the content of ergosterol strongly increased in all december’s samples with small variations between all three forage crops. Samples, where the summer harvest was performed in July had significantly lower content of ergosterol. Obtained results showed that level of monitored compounds was under limits in all samples.

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.

A Versatile Stability-indicating Liquid Chromatographic Method for the Simultaneous Determination of Atenolol, Hydrochlorothiazide and Chlorthalidone

2020 ◽  
Vol 16 (8) ◽  
pp. 1037-1051
Author(s):  
Ehab Farouk Elkady ◽  
Marwa Ahmed Fouad ◽  
Abdulgabar A. Ezzy Faquih
Keyword(s):  
Quality Control ◽  
Chromatographic Method ◽  
Degradation Products ◽  
Pharmaceutical Dosage Forms ◽  
Potassium Dihydrogen ◽  
Ich Guidelines ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic ◽  
Potassium Dihydrogen Orthophosphate

Background: Atenolol is a selective beta 1 blocker that can be used alone or in combination with hydrochlorothiazide or with chlorthalidone for the treatment of hypertension and prevention from a heart attack. Objective: The main target of this work was to improve modern, easy, accurate and selective liquid chromatographic method (RP-HPLC) for the determination of these drugs in the presence of their degradation products. These methods can be used as analytical gadgets in quality control laboratories for a routine examination. Methods: In this method, the separation was accomplished through an Inertsil® ODS-3V C18 column (250 mm x 4.6 mm, 5 μm), the mobile phase used was 25 mM aqueous potassium dihydrogen orthophosphate solution adjusted to pH 6.8 by using 0.1M sodium hydroxide and acetonitrile (77 : 23, v/v), the flow rate used was 1 ml/min and detection was achieved at 235 nm using UV. Results: All peaks were sharp and well separated, the retention times were atenolol degradation (ATN Deg.) 2.311 min, atenolol (ATN) 2.580 min, hydrochlorothiazide degradation (HCT Deg.) 5.890 min, hydrochlorothiazide (HCT) 7.016 min, chlorthalidone degradation CTD Deg 8.018 min and chlorthalidone (CTD) 14.972 min. Linearity was obtained and the range of concentrations was 20- 160 μg/ml for atenolol, 10-80 μg/ml for hydrochlorothiazide and 10-80 μg/ml for chlorthalidone. According to ICH guidelines, method validation was accomplished, these methods include linearity, accuracy, selectivity, precision and robustness. Conclusion: The optimized method demonstrated to be specific, robust and accurate for the quality control of the cited drugs in pharmaceutical dosage forms.

A Green Liquid Chromatographic Method For The Simultaneous Determination of Chlorpheniramine Maleate, Pseudoephedrine Hydrochloride and Propyphenazone

2019 ◽  
Vol 15 (6) ◽  
pp. 635-641
Author(s):  
Nadia M. Mostafa ◽  
Ghada M. Elsayed ◽  
Nagiba Y. Hassan ◽  
Dina A. El Mously
Keyword(s):  
Simultaneous Determination ◽  
Mobile Phase ◽  
Dosage Form ◽  
Chromatographic Method ◽  
Green Analytical Chemistry ◽  
Chlorpheniramine Maleate ◽  
Accuracy And Precision ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic

Background:The concept of green analytical chemistry prevails due to the growing environmental pollution.Objective:Our attempts are to develop simple and eco-friendly method which is non-harmful to the environment by producing minimal waste. In this context, a green liquid chromatographic method was applied for the simultaneous determination of chlorpheniramine maleate, pseudoephedrine hydrochloride and propyphenazone in their combined dosage form.Methods:Separation was carried out using X select HSS RP C18 analytical column (250 × 4.6 mm, 5μm) using methanol - 0.02 M phosphate buffer pH 3 - triethylamine (60:40: 0.1, by volume) as a mobile phase. The separated peaks were detected at 215 nm at a flow rate 1.0 mL/min.Results:Quantification was done over the concentration ranges of 1-25 µg/mL for chlorpheniramine maleate, 5-35 µg/mL for pseudoephedrine hydrochloride and 10-120 µg/mL for propyphenazone. The suggested method was validated with regard to linearity, accuracy and precision according to the International Conference on Harmonization guidelines with good results.Conclusion:It could be used as a safer alternative for routine analysis of the mentioned drugs in quality control laboratories.

Liquid Chromatographic Determination of Amiodarone Hydrochloride and Related Compounds in Raw Materials and Tablets

1994 ◽  
Vol 77 (6) ◽  
pp. 1447-1453 ◽  
Author(s):  
Pauline M Lacrok ◽  
Norman M Curran ◽  
Wing-Wah Sy ◽  
Dennis K J Goreck ◽  
Pierre Thibault ◽  
...  
Keyword(s):  
Raw Materials ◽  
Chromatographic Determination ◽  
Raw Material ◽  
Liquid Chromatographic Method ◽  
Limit Of Quantitation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Amiodarone Hydrochloride ◽  
Related Compounds

Abstract A liquid chromatographic method for the determination of amiodarone hydrochloride and 10 related compounds in drug raw material and for assay of drug in tablets was developed. The method specifies a 3 jxm Hypersil nitrile column (150 × 4.6 mm), a mobile phase of 1 + 1 acetonitrile–ammonium acetate buffer (0.1 M adjusted to pH 6.0 with 0.1 M acetic acid), a flow rate of 1 mL/min, and detection at 240 nm. The lower limit of quantitation of the related compounds is 0.02% or less. Drug contents in 2 raw material samples were 100.1 and 99.9% and ranged from 98.2 to 99.4% in 3 tablet formulations. Impurity levels in 2 samples of raw material from different manufacturers were ca 0.4%. The presence of 3 of the known related compounds in these samples was confirmed by liquid chromatographymass spectrometry. The method applied to raw materials was evaluated by a second laboratory and found to be satisfactory.

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