Pyridoxine chromatograms

FIGURE 16 HPLC chromatogram of water-soluble vitamins using ion-pair chromatography. LC conditions and peak identification are shown in the inset.The retention times of basic analytes (pyridoxine and thiamine) are strongly dependent of the concentration of ion-pairing reagent (1-hexanesulfonate) in the mobile phase. Reprinted with permission from Reference 17. 

Figure 32-10 Chromatograms illustrating separations of mixtures of ionic and nonionic compounds by ion-pair chromatography. Compounds (1) niacinamide, (2) pyridoxine, (3) riboflavin, (4) thiamine. At pH 3.5, niacinamide is strongly ionized, while riboflavin is nonionic. Pyridoxine and thiamine are weakly ionized. Column pt-Bondapak, C g, 4 mm X 30 cm. Mobile phase ...

Figure 9.19 Chromatograms and solvent data for standard mixture of vitamins. Solvent A 2.5mM pentane sulphonic acid in 25% methanol/75% 1% HOAc. Solvent B 2.5mM heptane sulphonic acid in 25% methanol/75% 1 % HOAc. Peaks (a) niacin (b) pyridoxine (c) riboflavin (d) thiamine. See text for other details.

Fig. 2 illustrates the CCC chromatogram of water-soluble vitamins obtained with the above solvent system, which comprise 1-butanol and aqueous 0.15 M monobasic potassium phosphate, including 1.5% of 1-octanesulfonic acid sodium salt. Riboflavin sodium phosphate, cyanocobalamin, riboflavin, pyridoxine hydrochloride, and thiamine nitrate were separated using the lower phase as the mobile phase. Riboflavin was found as an impurity contained in the riboflavin sodium phosphate sample. 

Figure 14.1 presents chromatograms of vitamins analysed in fruit drinks. The detection limit for thiamine hydrochloride deteetion was 9.2 ng/ml, whereas the limits for pyridoxine and cyanoeobalamin were 2.7 and 0.08 ng/ml, respectively. The proposed separation and detection procedure was applied sueeess-fully for quantitative evaluation of the studied B vitamins in pharmaeeutieal preparations and dietary supplements, and for routine control of multivitamin enriched foods. Based on those sueeessful results, we have developed also a method for analysis of vitamins Bg, B12 and Bi in seafood produets (Lebiedzinska et al. 2007). 

Figure 6 Chromatogram of water-soluble vitamins from standard solution. Ion pair chromatography with a reversed-phase Cig column (Tracer Spherisorb ODS 2, 250 X 4.6 mm i.d., 5 pm) UV detection at different wavelengths mobile phase (1 mL/min) contained octanesulfonic acid (5 mM), triethylamine (0.5%), glacial acetic acid (2.4%), and methanol (15%) at pH 3.6. Peak identities (1) nicotinamide (2) pyridoxal (3) pyridoxine (4) pyridoxamine (5) folic acid (6) riboflavin (7) cyanocobalamin (8) thiamin. (From Ref. 94.)...

Compared with HPLC, the GLC techniques mentioned above suffer from lack of sensitivity, poor peak shapes, and excessive tailing as well as inconsistent derivatization of certain vitamers (i.e., pyridoxine), which often resulted in appearance of more than one peak per vitamer on the chromatogram. GLC is not often used in routine Be analysis HPLC, which offers substantial advantages in simplicity and sensitivity, is generally preferred. 

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