Evaluation of a reagent-injection flow injection technique for sample background absorption elimination: determination of chloride in cigarettes

The applicability of reagent-injection flow injection (FI) technique in eli mination of background absorption was evaluated by using the FI determinati on of water-soluble chloride in cigarettes, based on the mercury thiocyanat e method, as a model. Some parameters of the proposed reagent-injection FI method were optimized and the proposed procedure had a linear range of 0-7. 5 mg l(-1) Cl, a detection limit of 0.02 mg l(-1) Cl, a sampling rate of 60 h(-1) and a relative standard deviation of 0.1% at 5 mg l(-1) Cl. Eight ci garette samples were analyzed by this proposed reagent-injection Fl method and the referential membrane dialysis Fl procedure. The relative errors wer e < 4.3%, and paired c-test shows that there are no significant differences between these two methods. As no dialysis unit was needed, the reagent-inj ection FI method has much simpler flow system than the existed CFA and FI m ethods. (C) 2001 Elsevier Science B.V. All rights reserved.