GF-AAS Determination of Aluminum in Wheaten Foodstuffs

Sample of wheaten food in a porcelain crucible was heated with 50 g·L-1 Mg(NO3)2 solution,evaporated to dryness and charred on electric hot plate. The crucible with its contents was then ignited at 600 ℃ for 4 h in a muffle furnace. The residue was treated with 50 g·L-1 NaOH solution,filtered into a 50 mL volumetric flask,and diluted to mark after adjusting the pH value to 5.0-5.5 with HCl. Aluminum in the sample solution was then determined by GF-AAS with Mg(NO3)2 added as matrix modifier. Temperatures of 1 200 ℃ and 2 400 ℃ were chosen for the ashing and atomization respectively in the operation of graphite furnace. The proposed method was applied to the analysis of the samples of biscuit,potato sticks and ready-to-eat noodle,and values of recovery obtained by standard addition method were in the range of 90.6%-95.4%. Values of RSD (n=7) found were 1.9%-5.0%.