Determination of lead in whole blood using a capacitively coupled 4wave plasma atomic emission spectrometer

Lead in whole blood was determined with a capacitively coupled microwave plasma atomic emission spectrometer with no dilution or addition of matrix modifiers. The sample was vaporized directly from the plasma-supporting electrode into the plasma, ensuring 100% transfer of the sample into the plasma. Microwaves were used to dry the sample, a low-power plasma was used to ash the sample, and a higher-power plasma was used to atomize and excite the sample. A detection limit of 7 ppb Pb (35 pg Pb) was obtained using 5-μl aliquots. The method was accurate (95% confidence) for blood containing 188 and 573 ppb Pb, but gave a high result with blood containing 48 ppb Pb. The precision was 15%.