Sequential Injection-HG-AFS Determination of Trace Amount of Lead Migrated from Food Contacting Materials

Sequential injection (SI)-HG-AFS was applied to the determination of lead migrated from food contacting materials. The sample was soaked in 40 g·L-1 acetic acid solution, and the solution obtained was diluted ten times to eliminate matrix interference. Hydride of Pb(Ⅱ) was generated from 1.2% (φ) HCl solution with 7 g·L-1 NaBH4 solution (dissolved in 7 g·L-1 NaOH solution) as reducing reagent. Linear relationship between values of fluorescence intensity and mass concentration of Pb was found in the range within 20.0 μg·L-1, with detection limit (3s) of 0.031 μg·L-1. Using blank sample of food contacting materials as matrixes, tests for recovery and precision were made by standard addition method, values of recovery and RSD′s (n=8) found were in the ranges of 96.6%-101% and 2.2%-4.4% respectively.