Temperature effects in capillary electrophoresis. 1: Internal capillary temperature and effect upon performance

1994 ◽  
Vol 38 (3-4) ◽  
pp. 207-214 ◽  
Author(s):  
J. H. Knox ◽  
K. A. McCormack
Keyword(s):  
Capillary Electrophoresis ◽  
Temperature Effects ◽  
Capillary Temperature

scholarly journals Development of a Capillary Electrophoresis Method for the Enantioselective Estimation of Primaquine in Pharmaceutical Formulations

2008 ◽  
Vol 91 (3) ◽  
pp. 536-541 ◽  
Author(s):  
Abdalla A Elbashir ◽  
Bahruddin Saad ◽  
Abdussalam Salhin Mohamed Ali ◽  
Muhammad Idiris Saleh
Keyword(s):  
Capillary Electrophoresis ◽  
Applied Voltage ◽  
Pharmaceutical Formulations ◽  
Fused Silica ◽  
Chiral Selector ◽  
Effective Length ◽  
Racemic Mixture ◽  
Injection Time ◽  
Relative Standard ◽  
Capillary Temperature

Abstract A capillary electrophoresis (CE) method has been developed that allows the separation and estimation of primaquine enantiomers using hydroxypropyl--cyclodextrin (HP--CD) as a chiral selector. The influence of chemical and instrumental parameters on the separation, such as type and concentration of CD, buffer concentration, buffer pH, applied voltage, capillary temperature, and injection time, were investigated. Good separation of the racemic mixture of primaquine was achieved using a fused-silica capillary (52.5 cm effective length 50 m id) and a background electrolyte composed of tris-phosphate buffer solution (50 mM, pH 2.5) containing 15 mM HP--CD as a chiral selector. The recommended applied voltage, capillary temperature, and injection time were 15 kV, 25C, and 6 s, respectively. Within-day and interday reproducibility of peak area and migration time gave relative standard deviation values ranging from 1.053.30. Good recoveries (range of 96.8104.9) were obtained from the determination of placebos that were spiked with 0.251.00 mg/L primaquine. The proposed CE method was successfully applied to the assay of primaquine diphosphate in pharmaceutical formulations (tablets).

Characterization of carbides in M50NiL

1991 ◽  
Vol 49 ◽  
pp. 606-607
Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law
Keyword(s):  
Temperature Effects ◽  
Base Composition ◽  
Lattice Parameter ◽  
Control Surface ◽  
Carbide Formation ◽  
Particle Sizes ◽  
Low Carbon ◽  
Fee Structure ◽  
Heat Treated

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).

Sign in / Sign up

Export Citation Format

Share Document