The previous study emphasized sample pretreatment involving rapid microwave digestion of sample prior to atomization in the graphite furnace. During numerous past experiments, recovery of added analyte was shown to be somewhat lower than expected, indicating possible analyte loss. Non- quantitative transfer of sample digest solution from digestion vessel to volumetric flask may partially account for this analyte loss. The use of non-optimal microwave energies and/or non-optimal digestion periods may also account for the poor recovery values obtained. Rather than taking the traditional sample pretreatment approach i.e. open vessel digestion of sample with concentrated acid using an external heat source, a modification of an earlier non-digestive technique is considered. The technique under consideration is a modification of the Triton X-1--/Sulfuric acid procedure. In this modification, furnace parameters have been modified to allow for more efficient removal of moisture and organic matrix prior to sample atomization. Sample drying temperatures and times have been modified through the addition of an extra drying step. Similarly, sample charring temperatures and times have been modified through the addition of a pre-charring step. Sample dilutions are performed manually rather than through a pre-programmed autosampler. Preliminary results obtained from analysis of U.S. Standard, Aluminum in 5% Albumin, Lot #1, the standard currently being used for method validation, shows good agreement with the value determined by he National Institute of Standards and Technology (NIST). The values determined by the current modified non-digestive technique were found to be within 5% of the value determined by the NIST. Recovery of a 20ppb analyte spike was found to be greater than 90%. Single standard addition correction of sample analyte value remained within 5% of that value determined by the NIST. Future application of the modified non- digestive technique will be directed toward aluminum determination in Antihemophilic Factor (Human) preparations.
