scholarly journals An Exploration on the Suitability of Airborne Carbonyl Compounds Analysis in relation to Differences in Instrumentation (GC-MS versus HPLC-UV) and Standard Phases (Gas versus Liquid)

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ki-Hyun Kim ◽  
Jan E. Szulejko ◽  
Yong-Hyun Kim ◽  
Min-Hee Lee

The relative performance figure of merits was investigated for the two most common analytical methods employed for carbonyl compounds (CC), for example, between high performance liquid chromatography (HPLC)-UV detector (with 2,4-dinitrophenylhydrazine (DNPH) derivatization) and thermal desorption (TD)-gas chromatography (GC)-mass spectrometry (MS) (without derivatization). To this end, the suitability of each method is assessed by computing the relative recovery (RR) between the gas- and liquid-phase standards containing a suite of CC such as formaldehyde (FA), acetaldehyde (AA), propionaldehyde (PA), butyraldehyde (BA), isovaleraldehyde (IA), and valeraldehyde (VA) along with benzene (B) as a recovery reference for the GC method. The results confirm that a TD-GC-MS is advantageous to attain the maximum recovery for the heavier CCs (i.e., with molecular weights (MW) above BA−MW ≥ 74). On the other hand, the HPLC-UV is favorable for the lighter CCs (like FA and AA) with the least bias. Such compound-specific responses for each platform are validated by relative ordering of CCs as a function of response factor (RF), method detection limit (MDL), and recovery pattern. It is thus desirable to understand the advantages and limitations of each method to attain the CC data with the least experimental bias.

Author(s):  
Raju Chandra ◽  
Manisha Pant ◽  
Harchan Singh ◽  
Deepak Kumar ◽  
Ashwani Sanghi

A reliable and reproducible reversed-phase high performance liquid chromatography (RP-HPLC) was developed for the quantitative determination of Remipril drug content from marketed bulk tablets. The active ingredient of Remipril separation achieved with C18 column using the methanol water mobile phase in the ratio of 40:60 (v/v). The active ingredient of the drug content quantify with UV detector at 215 nm. The retention time of Remipril is 5.63 min. A good linearity relation (R2=0.999) was obtained between drug concentration and average peak areas. The limit of detection and limit of quantification of the instrument were calculated 0.03 and 0.09 µg/mL, respectively. The accuracy of the method validation was determined 102.72% by recoveries method.


2020 ◽  
Vol 16 (8) ◽  
pp. 1106-1112
Author(s):  
Ibrahim A. Darwish ◽  
Nasr Y. Khalil ◽  
Mohammad AlZeer

Background: Axitinib (AXT) is a member of the new generation of the kinase inhibitor indicated for the treatment of advanced renal cell carcinoma. Its therapeutic benefits depend on assuring the good-quality of its dosage forms in terms of content and stability of the pharmaceutically active ingredient. Objective: This study was devoted to the development of a simple, sensitive and accurate stabilityindicating high-performance liquid chromatographic method with ultraviolet detection (HPLC-UV) for the determination of AXT in its bulk and dosage forms. Methods: Waters HPLC system was used. The chromatographic separation of AXT, internal standard (olaparib), and degradation products were performed on the Nucleosil CN column (250 × 4.6 mm, 5 μm). The mobile phase consisted of water:acetonitrile:methanol (40:40:20, v/v/v) with a flow rate of 1 ml/min, and the UV detector was set at 225 nm. AXT was subjected to different accelerated stress conditions and the degradation products, when any, were completely resolved from the intact AXT. Results: The method was linear (r = 0.9998) in the concentration range of 5-50 μg/ml. The limits of detection and quantitation were 0.85 and 2.57 μg/ml, respectively. The accuracy of the method, measured as recovery, was in the range of 98.0-103.6% with relative standard deviations in the range of 0.06-3.43%. The results of stability testing revealed that AXT was mostly stable in neutral and oxidative conditions; however, it was unstable in alkaline and acidic conditions. The kinetics of degradation were studied, and the kinetic rate constants were determined. The proposed method was successfully applied for the determination of AXT in bulk drug and dosage forms. Conclusions: A stability-indicating HPLC-UV method was developed and validated for assessing AXT stability in its bulk and dosage forms. The method met the regulatory requirements of the International Conference on Harmonization (ICH) and the Food and Drug Administration (FDA). The results demonstrated that the method would have great value when applied in quality control and stability studies for AXT.


2018 ◽  
Vol 15 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Bürge Aşçı ◽  
Mesut Koç

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.


2021 ◽  
pp. 107815522199120
Author(s):  
Mélanie Hinterlang ◽  
Amandine Gendron ◽  
Thomas Fleury ◽  
André Rieutord ◽  
Anastasia Vrana ◽  
...  

Background Imatinib is a protein-tyrosine kinase inhibitor which is currently only commercially available as a tablet dosage form in the strength of 100mg and 400mg. The elaboration of new oral liquid formulations is suitable in pediatrics and for patients who have difficulties to swallow, notably in the absence of commercial forms. This enables the adaptation of dosage and secure the administration. Objectives The formulation of an oral pediatric solution of imatinib at a concentration of 30 mg/mL and the evaluation of its stability for the treatment of pediatric patients with Philadelphia chromosome positive chronic myeloid leukemia. Methods The physicochemical stability parameters: appearance, pH, osmolality, and drug content of formulation were evaluated for 30 days when stored at 2–8°C. Concentration of solution was measured with a validated method using high performance liquid chromatography (HPLC) coupled with an absorbance UV detector. Equally, microbiological stability was performed. Results The remaining imatinib concentration was at least 95% of the initial concentration after 30 days stored in fridge temperature. No changes were observed regarding the physical properties of the formulation during the study period. Conclusions The stability study showed that the imatinib oral solution at a concentration of 30 mg/mL provides an alternative option at the commercial tablet dosage forms for pediatric patients and patients who have difficulties to swallow.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Amol S. Jagdale ◽  
Nilesh S. Pendbhaje ◽  
Rupali V. Nirmal ◽  
Poonam M. Bachhav ◽  
Dayandeo B. Sumbre

Abstract Background A new, sensitive, suitable, clear, accurate, and robust reversed-phase high-performance liquid chromatography (RP-HPLC) method for the determination of brexpiprazole in bulk drug and tablet formulation was developed and validated in this research. Surface methodology was used to optimize the data, with a three-level Box-Behnken design. Methanol concentration in the mobile phase, flow rate, and pH were chosen as the three variables. The separation was performed using an HPLC method with a UV detector and Openlab EZchrom program, as well as a Water spherisorb C18 column (100 mm × 4.6; 5m). Acetonitrile was pumped at a flow rate of 1.0 mL/min with a 10 mM phosphate buffer balanced to a pH of 2.50.05 by diluted OPA (65:35% v/v) and detected at 216 nm. Result The developed RP-HPLC method yielded a suitable retention time for brexpiprazole of 4.22 min, which was optimized using the Design Expert-12 software. The linearity of the established method was verified with a correlation coefficient (r2) of 0.999 over the concentration range of 5.05–75.75 g/mL. For API and formulation, the percent assay was 99.46% and 100.91%, respectively. The percentage RSD for the method’s precision was found to be less than 2.0%. The percentage recoveries were discovered to be between 99.38 and 101.07%. 0.64 μg/mL and 1.95 μg/mL were found to be the LOD and LOQ, respectively. Conclusion The developed and validated RP-HPLC system takes less time and can be used in the industry for routine quality control/analysis of bulk drug and marketed brexpiprazole products. Graphical abstract


Author(s):  
Klaudia Kokoszka ◽  
Agnieszka Kobus ◽  
Sylwia Bajkacz

The residues of antimicrobials used in human and veterinary medicine are popular pollutants of anthropogenic origin. The main sources of introducing antimicrobials into the environment are sewage treatment plants and the agricultural industry. Antimicrobials in animal manure contaminate the surrounding soil as well as groundwater, and can be absorbed by plants. The presence of antimicrobials in food of plant origin may pose a threat to human health due to their high biological activity. As part of the research, a procedure was developed for the extraction and determination of ciprofloxacin, enrofloxacin, cefuroxime, nalidixic acid and metronidazole in environmental samples (soil and parsley root). An optimized solid-liquid extraction (SLE) method was used to separate antimicrobials from the solid samples and a mixture of citrate buffer (pH = 4): methanol (1:1; v/v) was used as the extraction solvent. Solid phase extraction (SPE) with OASIS® HLB cartridges was used to purify and pre-concentrate the sample. The recovery of the developed method was in the range of 55–108%. Analytes were determined by high-performance liquid chromatography coupled with an ultraviolet (UV) detector and a tandem mass spectrometer (HPLC-UV-MS/MS). The procedure was validated and applied to the determination of selected antimicrobials in soil and parsley root samples. Five types of soil and five types of parsley roots of different origins were analyzed. The presence of nalidixic acid in the parsley root samples was found in the concentration range of 0.14–0.72 ng g−1. It has been shown that antimicrobials are absorbed by the plant and can accumulate antimicrobials in its edible parts.


Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 850
Author(s):  
Donghyuk Kim ◽  
Byungkyu Ahn ◽  
Kihyun Kim ◽  
JongYeop Lee ◽  
Il Jin Kim ◽  
...  

Liquid butadiene rubber (LqBR) which used as a processing aid play a vital role in the manufacturing of high-performance tire tread compounds. However, the studies on the effect of molecular weight, microstructure, and functionalization of LqBR on the properties of compounds are still insufficient. In this study, non-functionalized and center-functionalized liquid butadiene rubbers (N-LqBR and C-LqBR modified with ethoxysilyl group, respectively) were synthesized with low vinyl content and different molecular weights using anionic polymerization. In addition, LqBR was added to the silica-filled SSBR compounds as an alternative to treated distillate aromatic extract (TDAE) oil, and the effect of molecular weight and functionalization on the properties of the silica-filled SSBR compound was examined. C-LqBR showed a low Payne effect and Mooney viscosity because of improved silica dispersion due to the ethoxysilyl functional group. Furthermore, C-LqBR showed an increased crosslink density, improved mechanical properties, and reduced organic matter extraction compared to the N-LqBR compound. LqBR reduced the glass transition temperature (Tg) of the compound significantly, thereby improving snow traction and abrasion resistance compared to TDAE oil. Furthermore, the energy loss characteristics revealed that the hysteresis loss attributable to the free chain ends of LqBR was dominant.


2012 ◽  
Vol 95 (3) ◽  
pp. 845-849 ◽  
Author(s):  
Mohammad Mirzaei ◽  
Atieh Karimi Naeini ◽  
Mansoureh Behzadi

Abstract A simple and sensitive method has been developed for preconcentration and determination of genistein in soybeans. This method is based on cloud point extraction (CPE) of genistein from soybeans using ethylene glycol monoalkyl ether (Genapol X-080) as a nonionic surfactant. The concentration of extracted genistein was determined by HPLC with a UV detector. Optimum experimental conditions were established. With 5% Genapol X-080 (v/v), a liquid/solid ratio of 25:1 mL/g, and ultrasonic-assisted extraction at 40°C for 45 min, the extraction percentage of genistein reached its highest value. The preconcentration factor for genistein was about 16.5. The RSD for seven replicate measurements and the LOD were ±4.45% and 15.0 ng/mL, respectively. CPE is simple, inexpensive, and suitable for extraction of genistein from soybean. It uses environmentally friendly surfactants and offers a convenient alternative to more conventional extraction systems.


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