Nano-liquid chromatography (nano-LC) is a recent developed miniaturized technique with great potentiality, especially for analytical purposes. It is currently used in various application fields. Agrochemical, biomedical, pharmaceutical, environmental, proteomic and food, are the most important. Analytes separation is performed into capillary columns of small I.D. (<100 ?m) containing the stationary phase (SP). The SP can be formed by either packed particles or polymers (monolithic) or wall coated material. The limited capillary I.D. offers higher efficiency and higher sensitivity than HPLC mainly due to the decreased chromatographic dilution. This is a great advantage of nano-LC because also the mobile phase flow is reduced to nL/min offering better performances in coupling the separation system with a mass spectrometer (MS). On the other hand, such low flow rate presents some drawbacks, e.g., requires dedicated instrumentation and high skills of operators. The instrumentation must be carefully controlled taking in mind the reduction of band broadening and void volumes. Therefore connecting tubes, pump type, injection, detector etc. have to be properly selected. Concerning the sensitivity, it is true that this is higher than the one observed in conventional LC, however, considering the low injected sample volumes (few nL) often the analysis of complex matrices is difficult. As a result sample treatment or pre-concentration steps must be considered (e.g., on-column focusing, two dimensional separation, trap columns can be useful). Aim of this communication is the presentation of the features of nano-LC and its potentiality in the field of separation science. Instrumentation used, preparation of capillary columns packed with silica-based particles (porous and non-porous), selection of mobile phases will also be illustrated. Finally several examples documenting the applicability of this technique to the analysis of compounds of great interest in food chemistry (wine analysis, phytosterols in olive oil, amino-acid enantiomers in juices etc.) will be discussed.
Nano-Liquid Chromatography Applied to Food Analysis
Fanali Salvatore
2014
Abstract
Nano-liquid chromatography (nano-LC) is a recent developed miniaturized technique with great potentiality, especially for analytical purposes. It is currently used in various application fields. Agrochemical, biomedical, pharmaceutical, environmental, proteomic and food, are the most important. Analytes separation is performed into capillary columns of small I.D. (<100 ?m) containing the stationary phase (SP). The SP can be formed by either packed particles or polymers (monolithic) or wall coated material. The limited capillary I.D. offers higher efficiency and higher sensitivity than HPLC mainly due to the decreased chromatographic dilution. This is a great advantage of nano-LC because also the mobile phase flow is reduced to nL/min offering better performances in coupling the separation system with a mass spectrometer (MS). On the other hand, such low flow rate presents some drawbacks, e.g., requires dedicated instrumentation and high skills of operators. The instrumentation must be carefully controlled taking in mind the reduction of band broadening and void volumes. Therefore connecting tubes, pump type, injection, detector etc. have to be properly selected. Concerning the sensitivity, it is true that this is higher than the one observed in conventional LC, however, considering the low injected sample volumes (few nL) often the analysis of complex matrices is difficult. As a result sample treatment or pre-concentration steps must be considered (e.g., on-column focusing, two dimensional separation, trap columns can be useful). Aim of this communication is the presentation of the features of nano-LC and its potentiality in the field of separation science. Instrumentation used, preparation of capillary columns packed with silica-based particles (porous and non-porous), selection of mobile phases will also be illustrated. Finally several examples documenting the applicability of this technique to the analysis of compounds of great interest in food chemistry (wine analysis, phytosterols in olive oil, amino-acid enantiomers in juices etc.) will be discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
