Biogenic amines analytical techniques

It is used in IC systems when the amperometric process confers selectivity to the determination of the analytes. The operative modes employed in the amperometric techniques for detection in flow systems include those at (1) constant potential, where the current is measured in continuous mode, (2) at pulsed potential with sampling of the current at dehned periods of time (pulsed amperometry, PAD), or (3) at pulsed potential with integration of the current at defined periods of time (integrated pulsed amperometry, IPAD). Amperometric techniques are successfully employed for the determination of carbohydrates, catecholamines, phenols, cyanide, iodide, amines, etc., even if, for optimal detection, it is often required to change the mobile-phase conditions. This is the case of the detection of biogenic amines separated by cation-exchange in acidic eluent and detected by IPAD at the Au electrode after the post-column addition of a pH modiher (NaOH) [262]. 

Several analytical techniques including capillary electrophoresis, thin layer chromatography (TLC), GC, lEC, and HPLC, have been proposed for the determination of biogenic amines in various foods. Among these, RP-HPLC is considered the most suitable one. HPLC methods used for amine determination usually involve two steps amine extraction from the matrix and analytical determination. Depending on the complexity of food matrix and the selectivity of the final analytical determination, a further purification step may be necessary prior to the analytical determination. To ensure adequate sensitivity, a derivatization step is generally required before injection [282]. 

In recent years there has been a growing interest in the use of electrospray ionization-mass spectrometry (ESI-MS) either as a stand-alone technique, or following an analytical separation step like CE, to study and measure a wide variety of compounds in complex samples such us foods (Simo et al. 2005). ESI provides an effective means for ionising from large (e.g., proteins, peptides, carbohydrates) to small (e.g., amino acids, amines) analytes directly from solution prior to their MS analysis without a previous derivatization step. Santos et al. (2004) proposed the use of CE-ESI-MS for the separation and quantification of nine biogenic amines in white and red wines. More recently, the possibilities of two different CE-MS set-ups, namely, capillary electrophoresis-electrospray-ion trap mass spectrometry (CE-IT-MS) and capillary electrophoresis-electrospray-time of flight mass spectrometry (CE-TOE-MS) to analyze directly biogenic amines in wine samples without any previous treatment has been studied (Simo et al. 2008). 

Many analytical techniques such as, radiochemistry, gas chromatography, and liquid chromatography have been developed for the determination of biogenic amines, their precursors, and metabolites. HPLC with electrochemical detection is considered to be one of the most popular methods for determining biogenic amines, owing to its simplicity, versatility, sensitivity, and specificity. 

---