Determinacion de plomo en leche fresca, leche enlatada, leche temperatura ultra alta (UHT) y formulas para infantes utilizando espectrofotometria de absorcion atomica con horno de grafito (Spanish text).

摘要

The main objective of this research was to determine the presence of lead in samples of fresh milk elaborated in Puerto Rico, Ultra High Temperature (UHT), canned milk and infant formulas using graphite furnace atomic absorption spectrophotometer. The instrument's parameters were optimized. Trichloroacetic acid was added to the canned milk and infant formulas samples in order to promote the precipitation of proteins and liberation of lead. The fresh milk and UHT samples were exposed to room temperature for 48 hours in order to precipitate protein. All samples were then centrifuged and liquid supernatants analyzed. The results showed concentrations of lead ranging from 4.19 to 37.8 ng/mL. Infant formula soy base showed the highest concentration of lead with a mean of 37.8 ng/mL which exceed the FDA value of 20 ppb. The statistical analysis of variance showed significant differences between the lots from which the samples were taken.