RESUMO
In the present paper, uniform design U10* (10(8)) was used to optimize the condition of arsenic determination in vegetable samples by hydride generation-atomic fluorescence spectrometry. Mathematical model was established and regression analysis was done, and the optimized solutions to those equations were obtained by making use of the UD3.0 software. Combining the life-span of hollow cathode filament, noise of negative voltage and other factors, the optimal condition was obtained as follows: negative voltage was 280-360 V; lamp current was 50-70 mA; carrier gas flow rate was 500-700 mL x min(-1); KBH4 concentration was 15.0-20.0 g x L(-1); HCL concentration was 0.6-1.2 mol x L(-1); sample size was 0.5-1.0 mL. Two samples of vegetable were analyzed under the optimized condition. The results showed that the relative standard deviation was less than 3.6%, and the recovery was within 94.1%-101.3%, with their detection limits of 0.42 microg x L(-1). In this paper, as an effective method of experiment design, uniform design was introduced to hydride generation-atomic fluorescence spectrometry analysis with multifactors, which offered a good idea for the optimization of experiment conditions.
