Food analysis chromatographic modes

Many excellent discussions of natural occurrence, structure, characterization, and analysis of phenolic compounds are available in the literature, and a series of books devoted to flavonoid chemistry has also been published. Detailed discussions on various chromatographic modes, including HPLC, GC, column chromatography (CC), capillary electrophoresis (CE), PC, and TLC, of simple phenolics and polyphenols are also presented in the recent book, Handbook of Food Analysis, volume 1, edited by Nollet (1). Due to their diversity and the chemical complexity of phenolic compounds, this chapter is limited to phenolic compounds that are considered to be important to foods and the food industry. 

HPLC fulfills all of these criteria and is now used extensively in the analysis of samples from a variety of sources including mammalian tissue, plant tissue and food extracts. The overall efficiency of HPLC and the variety of chromatographic modes allows the majority of analyses to be performed by either reversed phase, reversed phase ion-pair, normal phase or ion-exchange HPLC. Other chromatographic modes such as size exclusion and affinity have found limited application in the chromatography of the vitamins. 

Due to the complicated composition of food, it is clear that reliable vitamin determinations require high chromatographic efficiency and detection sensitivity, as well as excellent detection specificity. Huorescence detection fulfills these requirements. This mode of detection is therefore virtually exclusively used in modern chromatographic vitamin Be analysis of food. Several methods suitable for food analysis, summarized in Table 4, have been described in the iiterature. 

Figure 4.19 GC/MS chromatogram of total ions recorded in SIM mode in the TCA and TCP analysis of a wine extract. Chromatographic conditions Injector and detector temperatures 200 and 240 °C, respectively oven temperature program 50°C for 5min, 1.5°C/min until 100°C, isotherm for 3min, 30°C/min until 250 °C, isotherm for 5 min. Carrier gas He column head pressure 8 psi. (Reproduced from J. Agric. Food Chem., 2002, 50, 1032-1039, Soleas et al., with permission of the American Chemical Society)...

A sensitive, selective, and fast LC-MS/MS method and a simple sample treatment were proposed for the analysis of amprolium in food samples. Hydrophilic interaction liquid chromatography allowed the retention of this cationic coccidiostat. The method provided an efficient chromatographic analysis in less than 3 min using isocratic elution mode (118). 

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