Validación de un método de determinación de Na, K, Cd, Pb y Hg por Espectrometría de Absorción Atómica en policosanol y extracto purificado de cera de caña

Abstract

An analytical methodology for the determination of Na, K, Cd, Pb and Hg by atomic absorption spectrometry in policosanol and purified extract of cane wax was developed and validated. The validation criteria were the following: linearity, proportionality, specificity, accuracy and precision in repeatability and reproducibility conditions. The limits of detection (LD) and the limits of quantification (LQ) were calculated in cases of Cd, Pb and Hg in two spectrometers of atomic absorption. In all cases the acceptance criteria were the same of the Catalan Section of Norms of Good Manufacture and Control of Quality, except in the cases of the LD and and LQ which noticed according to the demands of the pharmacopoeia for the control of heavy metals in similar products. In the linearity study the coefficients of variation of the response factors were inferior to 5 % and acceptable values for the variance of the total experimental error and the standard deviation of the slope, what denotes a good linearity. By the proportionality test was demonstrated that the system had not bias. For the two products and the five analysed elements the recovery was located between the 97 and 103 %, as indication of satisfactory recovery-accuracy of the method. For the specificity it was verified that in any case there is not interference of the matrix in the determination of Na and K.