Determination of lead in blood by chelation with ammonium pyrrolidine dithio-carbamate followed by tungsten-coil atomic absorption spectrometry

An inexpensive, bench-top blood Pb analyzer has been developed. The system is based on tungsten-coil atomic absorption spectrometry. Pb atomization oc curs on W-coils extracted from commercially available slide projector bulbs . The system has minimal power requirements: 120 ACV and 15 A. A small, com puter-controlled CCD spectrometer is used as the detector. A Pb hollow cath ode lamp is used as the source. Blood Pb is chelated with ammonium pyrrolid ine dithio-carbamate and extracted into methyl iso-butyl ketone (4-methyl 2 -pentanone). Twenty-microliter volumes of the organic phase are deposited o n the W-coil, dried at 1.4 A, charred at 2.3 A and atomized at 6.0 A. Graph ite furnace atomic absorption spectrometry is used as a comparison for W-co il results. Levels 1-4 of a NIST standard reference material 955b 'lead in bovine blood' are used to test accuracy and precision. The analytical figur es of merit for the system are: 12-pg instrument detection limit, 24-pg blo od detection limit and a characteristic mass of 28 pg. (C) 1999 Elsevier Sc ience B.V. All rights reserved.