The determination of calcium , iron and zinc in the milk powder by microwave plasma torch atomic emission spectrometry (MPT-AES)with the standard curve method w as studied by using microwave plasma torch(MPT)as ex citation light source, argon as support gas of pasma and sample solution being introduced into a pneumatic atomizer system .The effect of experimental co nditions including hydrochloric acid concentration in the sample solution, nitric acid concentration in the sampl solution, microw ave forward power , carrier g as flow rate, support gas flow rate on determination w ere optimized.The effect of co -ionized elements of sodium and magnesium on the emission intensity of calcium , iron and zinc w as investiga ted in detail .The detection limits of mass concentration for calcium , iron and zinc are 0.92 , 13.82 and 16 .27 μg/ L, respectively .The relative standard deviations (n =6)are less than 1 .79%. The linear rang es are 0.02 ~ 6, 0 .1 ~ 100, 0.1~ 20 mg/ L for calcium , iron and zinc , respectively .The results show that the proposed method is effective for the determination of the quality of calcium , iron and zinc in the milk powder in its accuracy , easy operation,high automation , low operation cost and rapidity .
2005, 25 (1):
30-32.