| Abstract: | A simple on-line flow injection analysis pre-concentration technique has been developed. The flow injection system consisted of a 4-channel peristaltic pump, two 6-way rotary injection valves containing a microcolumn of Chelex-100 resin, and a flame atomic absorption spectrometer, allowing the determination of lead at a concentration as low as ppb. The degree of pre-concentration depended on the injected sample volume. Lead contained in NBS 1634b and other heavy oil samples was determined using the system. Samples were ashed directly in a furnace at 550°C for two hours, dissolved with perchloric acid and then injected into the system. The sampling frequency also depended on the injected sample volume. |
