SEQUENTIAL DETERMINATION OF Zn, Fe, Mg, Ca, Na AND K IN SYNTHETIZED BABASSU FAME BY HIGH RESOLUTION CONTINUUM SOURCE FLAME ATOMIC ABSORPTION SPECTROMETRY

In this work, babassu FAME samples were synthesized by transesterification reaction under alkaline catalysis with sodium glyceroxide and by two steps process with KOH followed by H₂SO₄ as catalysts. A sequential multi-element method for determination of Zn, Fe, Mg, Ca, Na and K in synthesized babassu FAME by high resolution continuum source flame atomic absorption spectrometry (HR CS FAAS) was developed. The proposed method is based on a microemulsion formation by mixing the babassu FAME samples with 1-propanol and aqueous phase. The mass proportion of the added components was evaluated through a ternary diagram. External and matrix-matching calibration techniques with inorganic and organic standard were investigated. In the five-level spike-recovery test, satisfactory results were obtained by performing the matrix-matching calibration along with inorganic standard solutions. By using the optimized conditions, limits of detection in the range of 0.002-0.12 mg kg^-1 were obtained. Accuracy was attested by the agreement of the results obtained in the analysis of three certified reference materials. By applying the microemulsion system and HR-CS FAAS, the sequential determination of six elements was achieved. Therefore, the proposed method was a suitable alternative for metal determination in babassu FAME samples, with good sensitivities, accuracy, and a wide linear working range.

Keywords:
babassu FAME; microemulsion; trace metals; sequential determination; HR-CS FAAS