Americium(III)/curium(III) separation by countercurrent chromatography using malonamide extractants

2005 ◽  
Vol 93 (1) ◽  
Author(s):  
B. F. Myasoedov ◽  
T. A. Maryutina ◽  
M. N. Litvina ◽  
D. A. Malikov ◽  
Yu. M. Kulyako ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Stationary Phase ◽  
Flow Rate ◽  
Mobile Phase ◽  
Countercurrent Chromatography ◽  
Column Length ◽  
Isocratic Elution ◽  
Phase Systems ◽  
Phase Retention

AbstractThe separation of Am(III) and Cm(III) by countercurrent chromatography (CCC) was achieved using the liquid phase systems "diamide–hydrogenated tetrapropylene (TPH)–HNOThe following diamide extractants have been studied: (i) N,N´-dimethyl-N,N´-dibutyltetradecylmalonamide (DMDBTDMA), (ii) N,N´-dimethyl-N,N´-dioctylhexyl-ethoxymalonamide (DMDOHEMA) and (iii) N,N´-dimethyl-N,N´-dibutyldodecylethoxymalonamide (DMDBDDEMA). It is shown that these diamides can be used for the separation of Am(III) and Cm(III) by CCC. Increasing the column length leads to an increase of the stationary phase retention on the column while improving the Am/Cm separation. Increasing the speed of rotation of the centrifuge from 660 to 950 rpm also results in increasing the stationary phase retention but does not influence the resolution of the Am/Cm separation. Decreasing the flow rate of the mobile phase from 1.0 to 0.5 mL/min leads to a better resolution of Am and Cm separation. The best Am/Cm separation was achieved with systems based on DMDBDDEMA and DMDOHEMA in TPH using a two-layer coil column and an isocratic elution mode. The application of CCC makes it possible to separate the elements within 100 min: the Cm fraction contains 99.5% of Cm(III) and 0.6% of Am(III) inventories and the Am fraction contains 99.4% of Am(III) and 0.5% of Cm(III).

scholarly journals DETECTION AND PURIFICATION OF HARMFUL COMPOUNDS IN BEVERAGES USING HPLC

2016 ◽  
Vol 12 (20) ◽  
pp. 5215-5217 ◽  
Author(s):  
Rukkumani V ◽  
Saravanakumar M
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Stationary Phase ◽  
Retention Time ◽  
Mobile Phase ◽  
Migration Rate ◽  
High Performance ◽  
Human Beings ◽  
Carcinogenic Effects ◽  
Phase Retention

The presence of harmful compounds like caffeine and carbonated compounds in different beverages like soft drinks, fruit juices deserves great attention because of its toxic and carcinogenic effects on  human beings. We report on the detection and purification of those substances with the help of HPLC(High Performance  Liquid Chromatography).According to the migration rate, stationary phase and mobile phase, retention time we can extract the desire compounds. Depending upon the solvent and sample we can detect the compounds with  the  help  of the detector.The chromatogram will be  displayed and it can be viewed in the PC with the help of  Osiris  software. Compounds like Caffeine, Aspartame, Neotame, Saccharin, Maltodextrin, sucrose, fructose etc can be detected and purified. Detection and purification takes place in the column of HPLC where the process called adsorption takes place. Retention time can be calculated by the total time taken of a component that spends  in both mobile phase and stationary phase. It is always expressed in minutes

Adjustable column length using a water stationary phase in supercritical fluid chromatography

2019 ◽  
Vol 97 (10) ◽  
pp. 722-727
Author(s):  
Matthew T. Saowapon ◽  
Kevin B. Thurbide
Keyword(s):  
Stationary Phase ◽  
Supercritical Fluid ◽  
Supercritical Fluid Chromatography ◽  
Flow Rate ◽  
System Response ◽  
Column Length ◽  
Air Flow Rate ◽  
System Pressure ◽  
Relative Standard ◽  
Novel Method

A novel method for adjusting the column length during analysis in capillary supercritical fluid chromatography (SFC) is introduced. The approach is based on using a water stationary phase that can be partially ejected (or replenished) from the column as desired, without physically removing the supporting hardware elements. By flowing cool air through a sleeve surrounding the column in a heated oven, an axial thermal gradient along the length of the column was formed. This established a cooler region where the water stationary phase could be maintained and a hotter region where the coating was removed through dehydration. As such, the effective column length could be easily adjusted by changing the gradient via the air flow rate. Using this prototype arrangement, column lengths could be readily varied between 1.4 and 10 m. System response was also fairly rapid and changes took effect in under 1 min. Once a given length was established, retention times were highly reproducible with a relative standard deviation of 1.8% (n = 3). The method is cheaper and faster than the conventional method of storing numerous columns for manual switching. Further, it avoids the convolution of system pressure and flow rate that accompanies the pressure adjustments normally used to optimize capillary SFC separations. Results indicate that this approach could be a useful alternative for adjusting column length to optimize separation speed and resolution.

scholarly journals SIMULTANEOUS DETERMINATION OF TIGECYCLINE AND ITS POTENTIAL IMPURITIES BY A STABILITY-INDICATING RP-HPLC-UV DETECTION TECHNIQUE

2022 ◽  
pp. 75-82
Author(s):  
V. N. V. KISHORE ◽  
G. V. RAMANA
Keyword(s):  
Flow Rate ◽  
Mobile Phase ◽  
Hplc Method ◽  
Isocratic Elution ◽  
Rp Hplc ◽  
Ich Guidelines ◽  
Buffer Mixture ◽  
Bulk Drug ◽  
Tablet Dosage

Objective: Stability representing the RP-HPLC method was established for synchronized quantification of Tigecycline and its impurities. This method was confirmed for its applicability to both tablet dosage and bulk drug forms. Methods: Intended for an isocratic elution, a mobile phase containing methanol: 10 mmol Triethylamine Buffer mixture (75:25 v/v, pH 6.1) was used at 1 ml/min flow rate and Agilent ZORBAX Eclipse XDB C18 (250 mm × 4.6 mm, 5 μm) column. Results: At 231 nm as wavelength, high-pitched peaks of Tigecycline (Tig) and its impurities (1and2) were detected at 6.55, 8.73 and 4.87 min correspondingly. The linearity of tigecycline and its impurities (impurity-1 and 2 and) were estimated with ranging from 75–450 µg/ml for Tigecycline and 1–6 µg/ml for both impurity 1 and 2. The corresponding recognition limits (LOD and LOQ) of the tigecycline and its impurities were originated to be (1.37,0.047 and 0.071 µg/ml) and (4.15, 0.143 and 0.126 µg/ml). Conclusion: The technique was effectively stretched for stability signifying studies under different stress conditions. Justification of the method was done as per the current ICH guidelines.

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