HPLC analysis for trans-vitamin K1 and dihydro-vitamin K1 in margarines and margarine-like products using the C30 stationary phase

Quantitation of Vitamin K in Foods

“…Generally, lipase powder and a buffer such as phosphate buffer are added to the liquid sample, which is then incubated at 37 ° C for 90 -120 min. Subsequently, vitamin K is extracted with hexane [33,40,41,44,50,51] .…”

Trace Analysis of Carotenoids and Fat‐Soluble Vitamins in Some Food Matrices by LC–APCI‐MS/MS

“…In order to separate the two xanthophylls completely, we tested the Prontosil C 30 column, which is characterized by superior apolarity and had already been successfully applied by other workers to the analysis of carotenoids [23] and vitamin K 1 isomers [16,24] . After having optimized the elution conditions (see Section 19.2.5), all analytes were separated, with the exception of vitamin K 2 and α -tocopherol, and the elution order of lycopene and β -carotene were inverted (see Figure 19.4 ).…”

“…This compound group is relatively stable to heat and oxygen exposure, but is destroyed by light and alkali [8] . Therefore, saponifi cation cannot be used and it has been replaced by enzymatic hydrolysis (lipase) followed by liquid -liquid extraction [16] or, more simply, direct solvent extraction [16,17] .…”

Mobile phase additives for enhancing the chromatographic performance of astaxanthin on nonendcapped polymeric C30‐bonded stationary phases

“…To efficiently separate structurally similar carotenoids as well as their geometrical isomers, a reversed C 30 stationary phase was developed [31]. The C 30 phase demonstrated separation potential not only for carotenoids but also for tocopherols, ubiquinones, and retinoids [32,33]. Hence separation and metabolic profiling of numerous isoprenoids from complex biological samples became feasible [34,35].…”

“…For HPLC of isoprenoids on a RP-C 30 phase, the majority of applications use mixtures of methanol (MeOH)/methyl tert-butyl ether (MTBE) along with acetone/water and other solvents such as dichloromethane and chloroform. Since the C 30 phase was introduced, a few mobile phase additives have been employed to improve peak shape, resolution, and on-column recovery of isoprenoid separations applying UVVis or fluorescence detection [29,33,40]. The definite mechanism of these additives has not been entirely understood thus far.…”