Novel fiber coated with amide bridged-calix[4]arene used for solid-phase microextraction of aliphatic amines

Solid-phase microextraction (SPME) using a novel fiber coated with 25,27-dihydroxy-26, 28-oxy(2',7'-dioxo-3',6'-diazaoctyl)oxy-p-tert-butylcalix[4]arene/hydroxy-terminated silicone oil has been introduced as a rapid and sensitive pretreatment technique coupled to gas chromatography-flame ionization detection (GC-FID) for the detection of aliphatic amines without derivatization. Due to the introduction of the polar amide bridge in calix[4]arene, the new fiber shows good selectivity and sensitivity to the polar aliphatic amines in addition to its high thermal stability (380 degrees C), solvent stability and good reproducibility between fibers. The extraction temperature, extraction time, pH, and ionic strength of the matrix sample were modified to allow for maximum sorption of the analytes onto the fiber. The method proposed in this study showed satisfactory linearity, precision and detection limits. Practical applicability was demonstrated through the determination of trimethylamine (TMA) in fish tissue. Mean recovery of 92.5% (n = 5) was obtained for the fish extracts and the relative standard deviation was 4.9% (n = 5). The results of fish freshness assay indicate the present method is a validated and simple procedure for the simultaneous determination of TMA in fish.