Effects of the Release Agent on the Determination of Magnesium in Milk Powder by Flame Atomic Absorption Spectrometry

Objective:To assess the effect of release agents on the determination of Mg in milk powder by flame atomic absorption spectrometry(FAAS). Methods:By adding 2% nitric acid solution,lanthanum(La)solution or strontium(Sr)solution to the milk powder treated by microwave digestion,the Mg contents in the milk powder was determined by FAAS,and the results were compared with those obtained by inductively coupled plasma atomic emission spectrometry(ICP-AES). Resuts:The addition of release agent could effectively improve the accuracy of FAAS.Especially when the La solution is used as the release agent,RSD was between 1.6% and 2.0%,recovery rate was between 97.7% and 102.3%. The results obtained by FAAS are highly consistent with those obtained by ICP-AES. Conclusion:The addition of the La solution as a releasing agent was necessary to improve the accuracy and reliability,when the Mg contents in the milk powder was determined by FAAS.