Hydride generation – in-atomizer collection of Pb in quartz tube atomizers for atomic absorption spectrometry – a 212Pb radiotracer study

Abstract

Lead preconcentration on the quartz surface after plumbane generation was extensively studied in the separate quartz trap or in the compact trap-and-atomizer device by means of a laboratory prepared ²¹²Pb radioactive indicator. Plumbane generation efficiency of 95% was found. A large surface area is required for sufficient analyte trapping as found by autoradiography. The lead trapping efficiency in the separate trap is around 85% at 300 °C whereas 100% trapping is reached in the trap-and-atomizer device at the same temperature due to its greater inner surface. Volatilization of the trapped lead species at 800 °C is efficient for both the separate quartz trap and the trap-and-atomizer device. The non-volatilized lead fraction was below 5% in the trap-and-atomizer device at 800 °C. The non-volatilized lead fraction increases substantially in the presence of Bi. This was proved to be the mechanism of the serious Bi interference. Although 1–10 ng of analyte is typically preconcentrated in ultratrace analysis the quartz trap is capable of efficient trapping and subsequent volatilization of up to 200 ng Pb.