Evaluation of the effect of freezing milk samples on the refractive index for copper(II) serum determination

Resumo

This work aimed to evaluate the effect of freezing of raw and whole UHT milk samples on the refractive index for copper(II) serum (RICS) determination. Eighteen samples were used in this study (9 raw and 9 whole UHT milk samples). RICS values were determined before and after freezing on different days (1, 5, 8, 15, 22, 29 and 57 days). The RICS values from frozen samples were lower than from fresh samples. However, the reduction in RICS was considered acceptable because this value was below to the expanded uncertainty of the method. Freezing milk is adequate to preserve samples for RICS determination.

DOI: 10.14685/rebrapa.v6i1.142