This document describes a method for the direct analysis of milk powder using axially-viewed simultaneous ICP-OES. The method involves the use of aqueous standard quantitative calibration and a simultaneous ICP-OES system to determine the major, minor, and trace elements in milk powder.
The document details a method for determining major, minor, and trace elements in milk powder directly without wet digestion or dry ashing. It utilizes aqueous calibration solutions and corrects for viscosity effects using scandium as an internal standard.
Caesium is added to the sample stream to act as both an ionization suppressant and an internal standard for sodium and potassium. The method was validated against NIST Standard Reference Material 8435 Whole Milk Powder, showing good agreement between measured values and certified concentrations.
The method corrects viscosity effects by using scandium (361.383 nm—ionic line) as an internal standard.
The accuracy and validity of the method were assessed using NIST Standard Reference Material (SRM) 8435 Whole Milk Powder.