Gel mobile phase

Fig. 17. Gradient HPLC chromatogram of the 16-component star polymer mixture, stationary phase silica gel, mobile phase i-octane/THF,linear, 20-100% THF (from [92] with permission)...

Cephalosporines are derived from natural cephalosporin C produced by Cephalosporinum acre-monium. They possess a cephem nucleus (7-amino-cephalosporanic acid) substituted with two side chains. They are commonly divided into three classes differing in their spectra and toxicity. Cephalosporines can be analyzed both by normal and reversed-phase TLC or HPTLC hence, more efficient separation is obtained on sUanized gel than on bare, untreated silica gel. Mobile phases are polar and similar to those used for penicillins. Acetic add or acetates are very often components of solvents for normal phase (NP) TLC, the ammonium acetate-acetic acid buffer for RP TLC. All cephalosporines can be detected at 254 nm. The detection limit can be diminished by applying reagents such as ninhydrin, iodoplatinate, chloroplatinic acid, or iodine vapor. Alternative to UV detection is bioautography with, for instance. Neisseria catarrhalis. 

Polyolefin laminate Drug product stored in plastic hags, SPE preparation HPTLC. Plate = 10 x 20 cm silica gel. Mobile phase acetone - chloroform - concentrated sodium hydroxide (20 80 0.2). Photodensitometric detection, at 200 and 234 nm before derivitization, 388 nm after derivitization with ninhydrin and 580 nm after derivitization with Bratton/Marshall reagent. e-Caprolactam Eganox 1010 Butylhydrox)4oluene 4,4 -methylene dianiline 7... 

Fig. 5 Chromatograms obtained on four mixed oxide packing materials. Solute 1 = benzene 2 = dimethyl phthalate 3 = pyridine. Column packing material (a) silica-zirconia (b) silica-alumina (c) silica-titania (d) silica-magnesia (e) silica gel. Mobile phase, -hexane containing 1% methanol flow rate, 1 mL/min column temperature, ambient detection, UV 254 nm. (From Ref. [1].)...

G 4000//8 Gel. Mobile phase Tetrahydrofuran. Flow rate 1.7 mllmin. 

Fig. 3. Elution of polystyrene as a function of the degree of polymerization P and the eluent composition stationary phase silica gel mobile phase chloroform-carbon tetrachloride. (From [8] with permission)...

Fig. 6. Separation of hydroxy-terminated poly(butylene glycol terephthalate) as a function of the mobile phase composition stationary phase silica gel mobile phase THF-heptane peaks 1.2 solvent, peaks 3-7 nonfunctional homologues (n = 0-4), peaks 8-12 monofunctional homologues (n = 0-4), peaks 13-17 bifunctional homologues (n = 04). (From [2] with permission)...

Fig. 13. Separation of EPDM- q/i-PMMA by gradient HPLC stationary phase cyano-propyl-silica gel mobile phase iso-octane-THF. (From [36] with permission)...

Layers 1, Cellulose 2,4. Whatman silica gel 3, Merck Silica gel. Mobile phases l Butan-2-ol-gIacial acetic acid-water (3 1 1) 2,3 n-Butanol-glacial acetic acid-water (3 1 1) 4 n-Propanol-water(7 3). Source From Ref. 72a. 

Stationary phase Binder free Zirconium (IV) antimonate ion exchanger in H form, mixture of zirconium antimonate and silica gel (1 1) and silica gel. Mobile phase HNO, (10 -1.0 M), DMSO-O.I M HN03(10 0, 8 2, 6 4, 4 6, and 2 8), dioxane-0.1 M HNO, 8.2, 6 4, 4 6, and 2 8). Conditions Ascending technique, layer thickness 0.1 mm. Detection Standard spot test reagents. Remarks Quantitative separation of Ru (5-50 pg) from synthetic mixtures of metal ions. Ru after detection with 2% thiourea solution in 2 M HCI was eluted from working plate with 0.1 M HCl, filtered and determined spectrophotometrically applying the p-nitrosodimethylaniline method. The standard deviation was 8-25 ppt. 

Stationary Phase Silica gel. Mobile Phase Methanol-CHiCL (1 99). Detection Self-colored complexes. Conditions Ascending technique, applied spot (I mm diameter). Remarks An integrated laboratory experiment comprising of synthesis, spectroscopy (NMR and Mass) and thin layer chromatography of metal acetyl acetonates. Source C, Glidewell and J. S. Mckechnie. J. Chem. Educ. 65 1015 (1988). 

DS = double spots (00 and 95) nd = not detected T = tailed spot (hRi-URr > 30). Stationary phase Si, Sj, S, S4 and S5 ate silica gel impregnated with 0.1% aqueous solutions of copper sulfate, zinc sulfate, nickel chloride, cobalt chloride, and hexamine cobalt III chloride respectively plain silica gel. Mobile phase M = 0.1 M formic acid-DMSO-acetone (1 1 8) ... 

FIGURE 8.10 Chromatographic behavior of some diastereoisomers of menthols on silica gel. Mobile phases (v/v) 1, benzene 2, benzene-methanol (95 + 5) 3, benzene-methanol (75 + 25) 4, methanol. (Data from Petrowitz, H.-J., Angew. Chem., 23, 921,1960.)... 

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