The development of a miniaturized convectively heated closed-vessel digestion system that can decompose a great number of botanical samples simultaneously at slightly increased pressure can be very useful in elemental analysis by atomic spectrometry. Preliminary studies revealed that when the digestion is performed in a closed vessel without an outer metal casing in a heating block, only the bottom of the vessel is considerably heated. Therefore, the temperature of the vapor phase is lower than the temperature of the liquid phase and vapor condensation on the vessel walls takes place. Consequently, the pressure inside the vessel is reduced and a digestion tube with thinner walls can be used. As a result, the amount of time consumed in heating and cooling the samples is diminished. The aim of this Project is to develop and evaluate a closed-vessel digestion system equipped with borosilicate glass or quartz tubes without metal casings (jackets) using a mini heating block with 48 positions. The evaluation of the system will involve the digestion of botanical materials emphasizing the determination of macronutrients, micronutrients and inorganic contaminants by atomic spectrometric techniques. Accuracy and precision of the proposed method(s) will be checked by the use of certified reference materials.
News published in Agência FAPESP Newsletter about the scholarship: