Carotenoids HPLC analysis

Solvent — The transition energy responsible for the main absorption band is dependent on the refractive index of the solvent, the transition energy being lower as the refractive index of the solvent increases. In other words, the values are similar in petroleum ether, hexane, and diethyl ether and much higher in benzene, toluene, and chlorinated solvents. Therefore, for comparison of the UV-Vis spectrum features, the same solvent should be used to obtain all carotenoid data. In addition, because of this solvent effect, special care should be taken when information about a chromophore is taken from a UV-Vis spectrum measured online by a PDA detector during HPLC analysis. 

The HPLC analysis of milkweed, the food-plant source for Monarch butterflies, demonstrates that it contains a complex mixture of carotenoids including lutein, several other xanthophylls, xanthophyll epoxides, and (3-carotene, Figure 25.3b. There is a component in the leaf extract that is observed to elute near 8min, which has a typical carotenoid spectrum but is not identical to that of the lutein metabolite observed at near the same retention time in the extracts from larval tissue. 

QUANTITATIVE CAROTENOID COMPOSITION (PG/CELL), OBTAINED BY HPLC ANALYSIS, OF H. PLUVIALIS CELLS IN THE STATIONARY PHASE IN CULTURES WITH DIFFERENT CONCENTRATIONS OF NITRATE (G/L), ACETATE AND MALONATE (% W/V)... 

A.M. Pupin, M.J. Dennis and M.C.F. Toledo, HPLC analysis of carotenoids in orange juice. Food Chem. 64 (1999) 269-275. 

Recently we published data that even in countries with excellent food sources and availability, insufficient vitamin A supply will occur (Schulz et ah, 2007). The aim of this trial was to analyze vitamin A and p-carotene status and investigate the contribution of nutrition to vitamin A and p-carotene supply in mother-infant pairs of multiparous births or births within short birth rates. Twenty-nine volimteers aged between 21 and 36 years were evaluated for 48 hours after delivery. In order to establish overall supply, retinol and p-carotene were determined in maternal plasma, cord blood, and colostrum via HPLC analysis. A food frequency protocol was obtained from all participants. Regardless of the high-to-moderate socioeconomic background, 27.6% of participants showed plasma retinol levels below 1.4 pmol/liter, which can be taken as borderline deficiency. In addition, 46.4% showed retinol intake <66% of RDA and 50.0% did not consume liver at all, although liver contributes as a main source for preformed retinol. Despite a high total carotenoid intake of 6.9 3.9mg/day, 20.7% of mothers showed plasma levels <0.5 pmol/liter p-carotene. 

D. Application HPLC Analysis of Carotenoids and Carotenoid Esters in Red Bell Pepper (Ref. 66)... 

Finally, the field of metabolomics is still in its early stages of development. With advances in all the areas listed above (sample preparation, HPLC analysis, and MS analysis), the use of metabolomics to analyze metabolic pathways involving carotenoids may evolve from a simple targeted approach to a more sophisticated fingerprinting approach. 

Lietz, G. Henry, C.J.K. 1997. A modified method to minimise losses of carotenoids and tocopherols during HPLC analysis of red palm oil. Food Chem. 60 109-117. 

In the egg yolk, zeaxanthin and lutein appear to be the primary carotenoids responsible for yellow color (Smith and Perdue, 1966 Schiedt et al, 1985 Schaeffer et al, 1988). Schaeffer et al. (1988) utilized HPLC analysis to reveal over 20 carotenoid species in the yolks of hens fed typical layer diets. Hamilton et al (1990) recently reported that the oleoresin of red pepper could be supplemented to laying hens to yield egg yolks with increased redness and yellowness. The three major pigments isolated were trans-lutein, trans-zeaxanthin and trans-capsanthin. The authors noted that the incorporation of small amounts of reddish capsanthin is advantageous for intensifying the yellow color of yolks. 

Fig. m.5 Isocratic HPLC analysis of carotenoid standards. Condition 5- mi x 250-mm x 4.6-mm Vydac 201TP column, 90 10 methanol/acetonitrile mobile phase, 1.0 ml/min flow rate, visible detection at 450 nm, and column temperature 25°C [84]... 

Gradient HPLC Analysis Using C30 Carotenoid Column... 

Fig. 111.7 Gradient HPLC analysis of the natural products reference matruial carotenoids using procedure 4.2.3. Conditions 3- jm x 250-nun x 4.6-mm waters C30 column, 1.0 ml/min flow rate, visible detection at 450 mn, column temperature 35°C, solvent A = 50 mM ammmiium acetate in methanol, B = isopropyl alcohol, and C = THF (all solvent contain 0.1% TEA). Flow program 90% A/10% B linear gradient, 54% A/35% B/11% Cover 24 min, linear gradient to 30% A/35% B/35% C over 11 min, hold for 8 min, and then return to initial conditions over 10 min [84]...

Alternatively, it is possible to inject the solvent extract directly for HPLC analysis. For good quantitation this method requires an internal standard or very careful measurement of liquid volumes. McClean et al. (69) and Nierenberg and Lester (70) used acetonitrile to denature plasma proteins and then solubilized retinol with ethyl acetate 1-butanol (1 1) for direct injection Siddiqui et al. precipitated proteins from serum by addition of acetonitrile, centrifuged, and then injected the supernatant (71). Retinoids and carotenoids can be efficiently extracted from one volume of serum or plasma with three volumes of 2-propanol dichloromethane (2 1) followed by centrifugation an aliquot can be directly analyzed by HPLC (72,73). The risks of sample loss and degradation during processing can thus be avoided. 

Macula. HPLC analysis was used to study the distribution of carotenoids in the macula (206). The extraction procedure and HPLC analysis of macular carotenoids obtained from human donor eyes on a 5-pm Spherisorb ODS-1 C18... 

Other Human Tissues. Details of extraction procedures and isocratic as well as RP-HPLC analysis of carotenoids present in various human tissues have been summarized by Parker (218) and by Schmitz et al. (219). Cis and trans isomers of carotenoids may have different biological activities. Thus the isomeric composition of lycopene and P-carotene was determined in the serum of healthy volunteers and in seven human tissues obtained by autopsy soon after death, using RP-HPLC on a Merck 5-p.m C18 end-capped column with a solvent mixture of CH3OH/CH3CN/CH2CI2/H2O) (7/7/2/0.16) and a photodiode array detector (220). 

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