This article describes a method for determining blood lead using a reduced-palladium matrix modifier in graphite furnace atomic absorption. The method allows for the use of ashing temperatures as high as 1000°C for blood lead determination. A low background absorbance of 0.060 enables the use of the more sensitive 217.0 nm lead line. Background correction can be easily performed using a deuterium lamp. The high dilution of blood in 0.2% Triton X-100 allows for short drying and ashing times. The use of the L'vov platform is not necessary at high ashing temperatures, as interferences are reduced and atomization is more effective from the tube wall. Carbon buildup does not occur. Zeeman background correction is not required. Accuracy has been established through comparison with a solvent extraction method and mean values from the UK External Quality Assessment Scheme.
This document details a method for determining lead in blood using Graphite Furnace Atomic Absorption (GFAA). The method utilizes a reduced-palladium matrix modifier to allow high ashing temperatures (up to 1000 °C) and low background absorbance, enabling the use of the sensitive 217.0 nm lead line. The procedure was developed and validated using an Agilent SpectrAA-20 atomic absorption spectrometer and GTA-96 graphite tube atomizer.
| Wavelength | 217.0 nm |
|---|---|
| Slit width | 0.5 nm |
| Lamp current | 7 mA |
| Measurement time | 1.0 sec |
| Background correction | On |
| Replicates | 3 |
| Sample volume | 50 pL |
| Diluent concentration | 0.2% w/v |
| Modifier concentration | 500 mg/L |
The method uses the 217.0 nm lead line.
Normally 50 pL of blood is taken, though smaller volumes can be used.
Deuterium arc background correction is used.
Nitrogen is used for drying and atomization, while Argon is used for ashing.