Stationary phase condition

Fig. 3-1. Separation of racemic 3,5-dinitrobenzamido leucine Al.A -diallylamide on silica and polymer-based chiral stationary phases. Conditions column size 150 x 4.6 mm i.d. mobile phase 20 % hexane in dichloromethane flowrate 1 mL min injection 7 pg. Peaks shown are l,3,5-tri-rert.-butylbenzene (1), R-enantiomer (2) 5-enantiomer (2 ). (Reprinted with permission from ref. [8]. Copyright 1997 American Chemical Society.)...

Keywords. Capillary electrochromatography, Theory, Electroosmotic flow, Separation, Instrumentation, Column technology, Stationary phase, Conditions, Applications... 

Figure 3.16 Chromatogram of hydantoins on polymethacrylate stationary phase. Conditions columns, Shodex RSPak DE613 (methacrylate gel) eluent, 1 1 mixture of 0.033 M disodium hydrogen phosphate and potassium dihydrogen phosphate flow rate, 2.0 ml min-1 detection, UV 210 nm temperature, 50 °C. Compounds 1, R = (CH2)2C02H 2, R = CH2OH 3, R = H 4, R = CH3 and 5, R = C2H5.

Eddy diffusion is a result of the presence of particles of stationary phase material in a column, and depends on the stationary phase conditions, shape of the column, and the structure of the stationary phase material. The influence of the stationary phase material can be divided into the particle size (dp), the shape of the particles, and the porosity of the particles. The standard deviation for peak broadening due to the particles is described by [Pg.102]

FIGURE 4.3 Separation of metoprolol enantiomers by LC and SFC on a Chiralcel OD stationary phase. Conditions (a) The LC separation was performed with 20% 2-propanol in hexane with 0.1% (v/v) diethylamine at 0.5 mL/min, selectivity (a) = 2.67, and resolution (Rs) = 4.8. (b) The SFC separation was performed with 20% methanol, which contained 0.5% isopropylamine, in carbon dioxide at 2.0 mL/min, 15MPa, and30°C a = 2.77,andRs = 12.7. (Adapted from Phinney, K.V. 2000. Anal. Chem. 72 204A-211A. With permission.)... 

For the incoming wave, this stationary phase condition is d(—kr — Et/h)/dk — 0, from which we know the motion of the wave packet... 

MICROPELLICULAR AND POROUS STATIONARY PHASES. In order to compare the features of micropellicular and porous stationary phases in rapid protein HPLC, experiments were conducted with two columns of similar size, each one of which was packed with different stationary phase and operated under comparable conditions. In this experiment the results of which are shown in Figure 10, the operational conditions were optimized for the micropellicular stationary phase (conditions A) and used subsequendy for separation of the same mixture with the porous stationary phase under identical conditions. Thereafter, the elution conditions were optimized for the column packed with the porous stationary phase (condition B) and the experiment was repeated with the column packed with micropellicular stationary phase. The chromatograms are depicted in Figures 10 and 11 and the results of the two approaches are summarized in Table III. 

Figure 6 The effect of increasing the ionic strength on the EOF mobility of Nucleosil C-18 wide-pore octadecylated silica stationary phases. Conditions column 55 cm (40 cm packed length) x 100 pm i.d. Eluent actonitrile-Tris (pH 9.0) (60 40, v/v) ionic strength variable. Temperature 25°C. Dectection 214 nm. Voltage 30 kV. (o) 7-pm Nucleosil 4000 A, ( ) 7-pm Nucleosil 500 A, (A) 5-pm Nucleosil 120 A, and ( ) 3-pm Spherisorb ODS-1, 80 A. (Reprinted with permission from Ref. 46, copyright 2001, with permission from Elsevier Science.)...

Evaluating p in stationary phase approximation we get something new. The stationary phase condition is given by... 

Estimate or measure the column saturation capacity under several mobile-phase and stationary-phase conditions, including different temperatures. 

Fig. 9.34. Influence of chromatographic conditions on retention and/or enantioseicctivity using CSP I (see Fig. 9.32) a.s the stationary phase (conditions T. 2.5°C flou rate. I ml/min UV detection), (a) Influence of mobile phase pH on k , and u of B/-lcucine (mohilc phase McOH-ammonium acetate (80 20) pHa adjusted with AcOH). (b) Influence of buffer concentration on retention (In/ , ) and enantioseicctivity (Inor) of B/-leucine (mobile phase MeOH-ammonium acetate (80 20) pH., = 6.0). (c) Influence of mobile phase solvent type on enantioseicctivity (Ina) of 3-phenyl lactic acid at different buffer cxincentrations (mobile phases water, methanol, acetonitrile, respectively, and acetic acid (mM sec plot -triethylaniine = 4 I). (d) Influence of temperature on Ina of DNS-valine (mobile phase MeOH-O.I M ammonium aeetate (80 20) pHa = 6.0) (reprinted with permission from Ref. 1388 ),...

Because the initial vibrational state for absorption spectra often is v = 0, the vibrational nonstationary state typically produced initially is an only slightly distorted Gaussian wavepacket centered at R"g. Conservation of momentum requires that this approximately minimum-uncertainty wavepacket be launched at the turning point on the upper surface, R e = R"g, which lies vertically above R"g. [This is a consequence of the stationary phase condition, see Sections 5.1.1 and 7.6 and Tellinghuisen s (1984) discussion of the classical Franck-Condon... 

Figure 6. Separation of a range of fluorosllyl derivatives on a capillary column, SG-30 stationary phase. Conditions temperature program, 50-200 C at 6°C/mlm. Peak Identification Is CjjF3 represents a trlfluoro-n-alkylsllane, CxF2 dlfluoro-n-alkylmethylsllane, and C F a fluoro-n-alkyldlmethylsllane.

Polymer Mobile phase Stationary Phase Conditions Analytical application Investigators ... 

Polymer Mobile phase Stationary phase Conditions... 

Fig. 8. Retention as a function of eluent pH for strongly basic or cationic substances on three different stationary phases. Conditions acetonitrile/60 mi citrate buffer (1 1, v/v), 35 °C (from [17]).

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