Optimization of thermogravimetric analysis of ash content in honey

Abstract

A factorial design to evaluate ash content in honey by thermogravimetry as well as to establish the optimum analysis conditions that produce ash values in agreement with those obtained by the official method (gravimetry) was executed. Heating rate and use of fiber glass paper effects were significant as was the interaction effect between them. Lower heating rates and the use of fiber glass fiber paper are recommended to provide the complete incineration of honey samples by thermogravimetry. To confirm these results and to establish the optimized conditions a completely randomized two block design was executed investigating three procedures: thermogravimetry with fiber glass paper at heating rates of 5 and 10 ºC min-1 and standard gravimetry. Only the thermogravimetric method carried out at 5 °C min-1 presented ash content averages in agreement with those obtained by the official method. In this way, TG/DTG can be indicated as an alternative method to gravimetry for this determination in honey samples.