Abstract

Amines are important biological compounds, and so their analysis and monitoring in various matrices is worthy of investigation and development.Due to the polar nature of amines, chromatographic analysis of free amines is generally unsatisfactory owing to adsorption and decomposition of the solute on the column, resulting in peak tailing and losses. Therefore, many derivatization reactions are employed to reduce the polarity, improve chromatographic separation of analytes, and increase selectivity and sensitivity of detection. In addition, the sample matrix contains other compounds at the same or higher concentration levels, making determination difficult and sometimes impossible. An important solution to this problem is derivatization of analytes, causing changes in their structures and properties, thus allowing differentiation of the analyte from other compounds present in the sample.A number of derivatization reactions including acylation, silylation or carbamate formation can be applied to amine compounds. In a chromatographic system, these reactions can be performed as pre-column, on-column, or post-column. Attempts have been made in both off-line and online approaches. Off-line derivatization is simple but time-consuming and labor intensive, particularly when large numbers of samples are involved and may increase the risk of loss or contamination. An alternative approach is to convert analytes by online derivatization using flow methods, so avoiding the drawbacks of off-line procedures. Online derivatization can be performed prior to chromatographic separation. This offers advantages for analytes with poor separation due to strong adsorption on the stationary phase, or labile compounds, which may easily decompose or react with other components during chromatographic separation.Solventless sample preparation techniques based on the extraction of analytes in sorption processes are effective and an environmentally friendly alternative to solvent extraction procedures. This type of extraction includes solid phase microextraction (SPME) and stir bar sorptive extraction (SBSE), with both techniques having been successfully applied to in situ derivatization of amine compounds. SPME and SBSE in combination with chromatographic techniques enable selective and sensitive analysis of amine derivatives in various matrices.Both techniques are simple and economical, do not require preliminary sample preparation steps, and reduce the volume of solvents used.

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