CHEMILUMINESCENCE MEASUREMENT OF TERTIARY-AMINES USING THE CONTINUOUS-ADDITION-OF-REAGENT TECHNIQUE - DETERMINATION OF TRIMETHYLAMINE IN FISH SAMPLES

The continuous-addition-of-reagent technique was used as an effective means for enhancing the performance of energy transfer chemiluminescen ce-based determinations. For this purpose, the reaction between tertia ry aliphatic amines and sodium hypochlorite in alkaline medium contain ing fluorescein as sensitizer was chosen. The influence of experimenta l variables such as the addition rate and sodium hypochlorite concentr ation, pH and fluorescein concentration on the maximum reaction rate w as assessed and compared with that observed when using Rhodamine B as sensitizer. The method based on fluorescein exhibited the better analy tical features (e.g. calibration graph for trimethylamine was linear o ver a wide such range as 10-2500 nmol, with relative standard deviatio n of 2.6%). The proposed method allows the indirect determination of p rimary amines (viz. methyl-and ethylamine) and compares favourably wit h recent alternatives to the determination of trimethylamine in fish t issue (mean recovery 101.0% and standard deviation 2.7). Some aspects on the degradation during storage of fish samples are discussed. (C) 1 997 Elsevier Science B.V.