[Determination of trace extractable lead in artificial acid sweat from ecological textiles by GFAAS]

Extractable trace level lead in artificial sweat solution from ecological textiles is a key item limited by eco-textile standard. But the content of this extractable Pb is not so easy to determine for the strict limit of eco-textile standard, the complicatedness of extractable solution matrix and the strong background interference of NaCl. In the present paper a method for the determination of trace extractable lead in artificial acid sweat from ecological textiles by graphite furnace atomic absorption spectrometry (GFAAS) is described. Based on a number of experiments by using different single and mixed matrix modifiers including (NH4)2 H2PO4, NH4 NO3, Pd(NO3)2, Ni(NO3)2 and ascorbic acid, an effective modifier and its quantity were selected and the graphite furnace operating parameters were optimized. Experimental test results revealed that adding 5 mL (1 : 1) mixed solution of 50 g x L(-1) ammonium nitrate and 100 mg x L(-1) palladium regent was an effective way to inhibit volatile lead and reduce background signals. The detection limit could reach a low level of 0.7 microg x L(-1). The relative standard deviation was 3.2%. Under the optimum experimental conditions, the recoveries ranged between 95.5% and 105%.