Determination of sulfides in synthesis and isomerization systems by reversed-phase ion-pair chromatography with a mobile phase containing tetramethylene oxide as organic modifier

2003 ◽  
Vol 57 (7-8) ◽  
pp. 543-547 ◽  
Author(s):  
XiuYan Pang ◽  
HanWen Sun ◽  
YanHuan Wang
Keyword(s):  
Mobile Phase ◽  
Reversed Phase ◽  
Ion Pair ◽  
Organic Modifier ◽  
Ion Pair Chromatography ◽  
Tetramethylene Oxide

Chromatography of Mo(VI) and W(VI) chelates with 2,3-dihydroxynaphthalene

1990 ◽  
Vol 55 (2) ◽  
pp. 372-378
Author(s):  
Milan Vrchlabský ◽  
Naděžda Pollaková ◽  
Aleš Hrdlička
Keyword(s):  
Phosphate Buffer ◽  
Mobile Phase ◽  
Detection Limits ◽  
Reversed Phase ◽  
Ion Pair ◽  
Organic Modifier ◽  
Ion Pair Chromatography ◽  
Counter Ions ◽  
Glass Column ◽  
Tenfold Excess

Mo(VI) and W(VI) were separated in the form of their anionic chelates with 2,3-dihydroxynaphthalene (DHN) by reversed phase ion-pair chromatography. The effect of the organic modifier content and concentration of tetrabutylammonium cations (TBA) in the mobile phase and the effect of concentration of DHN in the injected sample on the separation were studied. The best results were attained by using a mobile phase containing DHN (0.5 mmol dm-3), TBA counter-ions (10 mmol dm-3) and phosphate buffer (50 mmol dm-3) in a medium of 30% (v/v) methanol and 30% (v/v) acetonitrile at pH 7 and by injecting Mo(VI) and W(VI) samples containing DHN in a tenfold excess. On a CGC glass column 150 . 3.3 mm i.d. packed with Separon SGX C18 (5μm), the solutes were separated at resolutions of Rij = 1.0 (DHN-Mo) and 1.6 (Mo-W). The detection limits at 240 nm were 0.5 and 0.2 nmol for Mo(VI) and W(VI), respectively.

scholarly journals Rapid Determination of Thiamine, Riboflavin, Pyridoxine, and Niacinamide in Infant Formulas by Liquid Chromatography

2002 ◽  
Vol 85 (4) ◽  
pp. 945-951 ◽  
Author(s):  
David C Woollard ◽  
Harvey E Indyk
Keyword(s):  
Liquid Chromatography ◽  
Mobile Phase ◽  
Rapid Determination ◽  
Reversed Phase ◽  
Ion Pair ◽  
Infant Formulas ◽  
Ion Pair Chromatography ◽  
Naturally Occurring ◽  
Sample Extract

Abstract A simplified, simultaneous determination of vitamins B1, B2, B3, and B6 in supplemented infant formulas was developed from a single deproteinized sample extract, with analysis by reversed-phase, ion-pair chromatography with an acidified methanol–water mobile phase. The dioctylsulfosuccinate counter-ion facilitates unique retention of the pyridine-based vitamins (niacinamide and pyridoxine) and allows for concurrent measurement of both the pyridoxal and riboflavin 5′-phosphate endogenous components of milk. Other naturally occurring undetected vitamin congeners have minimal analytical significance. UV detection is used for niacinamide, and programmed fluorescence detection is used for riboflavin and the B6 vitamins. Thiamine is routinely determined sequentially under modified elution conditions.

Reversed-phase ion-pair chromatography in determination of sinomenine contents in Sinomenium acutum

2010 ◽  
Vol 30 (2) ◽  
pp. 193-195
Author(s):  
Hui WANG ◽  
Qing YE ◽  
Liang ZHAO ◽  
Wen-jun TIAN ◽  
Guo-qing ZHANG
Keyword(s):  
Reversed Phase ◽  
Ion Pair ◽  
Ion Pair Chromatography ◽  
Sinomenium Acutum

Reversed-phase ion-pair chromatography with UV-absorbing ions in the mobile phase

1981 ◽  
Vol 218 ◽  
pp. 31-43 ◽  
Author(s):  
M. Denkert ◽  
L. Hackzell ◽  
G. Schill ◽  
E. Sjögren
Keyword(s):  
Mobile Phase ◽  
Reversed Phase ◽  
Ion Pair ◽  
Ion Pair Chromatography
Sign in / Sign up

Export Citation Format

Share Document