2.2.2. Estimation of zinc content
Zinc content in lactose–zinc complex was estimated by atomic absorption spectrophotometer (AAS) (AA-7000, Shimadzu, Tokyo, Japan) using the method of AOAC (2005). 100 mg of sample was subjected to ashing (550 °C for 8 h), solubilized in tri acid mixture (HNO3:HClO4:H2SO4 in 3:2:1 ratio) and heated for complete dissolution. Samples were diluted suitably for analysis by AAS at λmax 213.9 nm.