A simple gravimetric methodology to determine soil particle density

Abstract

Soil particle density is commonly determined using the pycnometer and the volumetric flask methods. These methods could be improved or even replaced to simplify the routine analysis, reduce analysis time and generation of residues, and minimize the maintenance costs of sophisticated equipment. We aimed to develop a practical methodology to determine particle density using only a precision scale, so the method is purely gravimetric. This value is obtained indirectly by the alcohol mass, measured on a precision scale, and divided by its density. The new methodology presented a coefficient of variation and sampling error lower than 4%. Regression analysis between the standard methods and the purely gravimetric method had coefficients of determination greater than 0.89. In addition, the means of the purely gravimetric methodology were statistically similar to the other methods. The purely gravimetric method presented the lowest variation, probably because this method has fewer phases to be completed up to the determination. Besides detecting minor variations of mass, this methodology allows the reading of a single value for the measurements, which are presented in a display. The proposed method provides a low-cost and reliable estimate for particle density and might replace the current standard methodologies.