Validação do método analítico para detecção de saxitoxinas (STX e dc-SXT) por cromatografia líquida de alta eficiência com detector de fluorescência e derivatização pré-coluna

Abstract

The method of reversed-phase high-performance liquid chromatography with fluorescence detection (HPLC- FLD) and pre-column derivation was validated for the detection and quantification of saxitoxin (STX) and decarbamoil - saxitoxin (dcSTX) provided from an axenic strain of Cylindrospermopsis raciborskii. The previously mentioned validation was performed in order to give credibility to analytical method. To that end, it was used parameters, such as selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision and robustness to ensure the quality of the method. The results showed good selectivity, demonstrating that the method had the ability to measure the toxins in an array even in the presence of other components. The linearity presented a correlation coefficient (r) greater than 0.999 for STX and dc- STX in a working range of 4.5 to 150 mg L-1 for STX and 3.0 to 132 mg L-1 to dcSTX, showing that the method has the capacity to deliver results directly proportional to the concentration of detected analyte. The method's sensitivity was measured by LOD and LOQ, obtaining satisfactory results for the type of analysis performed. As permitted by the legislation, the method obtained a good precision and accuracy for the toxins studied at different levels of concentration and also proved robust, since it was insensitive to small variations that could occur during the analysis.