A novel silica trap for lead determination by hydride generation atomic absorption spectrometry

A novel silica trap for lead determination at concentration levels of ng/l was developed using hydride-generation atomic absorption spectrometry. The device consists of a 7.0-cm silica tubing which is externally heated to a desired temperature. The lead hydride vapor is generated by a conventional hydride-generation flow system. The trap is placed between the gas–liquid separator and silica T-tube; the device traps analyte species at 500 °C and releases them when heated further to 750 °C. The overall efficiency is 49%. The presence of hydrogen gas is required for revolatilization; O2 gas must also be present. The analytical plot is linear up to 2.0 ng/ml for a collection period of 60 s. The response is also linear with respect to increasing collection periods up to 4 min. For 60-s trapping, the detection limit is 19 ng/l.