1994 Volume 43 Issue 1 Pages 39-43
A new method for the direct determination of lead at the 10 ppb level in powdered biological samples by Zeeman-AAS with solid sampling technique using a miniature cup has been established. In this case, the concentration of lead in powdered biological samples is lower than that of the detection limit of Z-AAS, therefore these biological samples must be concentrated by a pre-ashing method with a conventional electrothermal Muffle furnace. The standard addition method for solid sampling technique (3 point estimation method) is proposed for the direct determination of lead at the 10 ppb level. Heating conditions of 500°C, 30 min for the pre-ashing concentration method are recommended.It has been ascertained that lead is not volatilized under these conditions, and it has been found that accurate analytical results for the direct determination of lead at the 10 ppb level in powdered biological standard samples, such as those issued by NIES, NIST etc. are obtained.
