Determinação de aminas biogênicas em amostras de alimentos utilizando a eletroforese capilar

Abstract

Food safety issues usually relate several quality indicators, such as biogenic amines (BAs). These BAs are produced by all living organisms, possess biological activity and may be present in a variety of foods and beverages. Brazilian legislation only established maximum levels for histamine in the muscle of some fresh fish species. The development of analytical methodologies for determination of biogenic amines in foods is relevant because of their toxicological effect for consumers. The present work developed a new analytical method for separation and quantification of BAs (putrescine, cadaverine, tyramine, histamine, tryptamine and benzylamine as internal standard) in foods, using capillary electrophoresis as analytical technique. Although derivatization of amines with dansyl chloride (DNS-Cl) has been widely used for other separation techniques, there are no reports in the literature on the use of DNS-Cl for capillary electrophoresis. The main advantages of the proposed method were the simplicity of the derivatization procedure (5 min at room temperature) and rapid analysis (less than 11 min). BA-DNS adducts (with maximum absorbance at 214 nm) were separated using a voltage of 18 kV and a temperature of 23 °C. A solution of phosphoric acid 120 mmol L-1 containing 5% v/v of acetonitrile pH 2.50 adjusted with triethylamine was used as running electrolyte. Samples were injected using the hydrodynamic mode (25 mBar × 6 s). The analytical curve was linear over the range of 1.0 to 10.0 mg L-1 for each amine (R ≥ 0.997). Repeatability and intermediate precision ranged from 0.9 to 9.9 % and 5.5 and 14.9 %, respectively. The method presented satisfactory values for limit of detection (42 - 417 μg L-1) and limit of quantification (141 - 1,389 μg L-1) without preconcentration process; limit of detection ranged for 7 to 45 μg L-1 and limit of quantification ranged for 25 to 145 μg L-1 with preconcentration process. The developed method was successfully applied for evaluating foods degradation and for quantitative determination in yoghurt and white cheese samples.