| Referências: |
1. HOWARD, A. G.; STATHAM, P. J.; Inorganic trace analysis: philosophy and practice, John Wiley & Sons, New York, 1997. 2. VANDECASTEELE, C.; BLOCK, C. B.; Modern methods for trace element determination, John Wiley & Sons, New York, 1997. 3. STOEPPLER, M.; Sampling and sample preparation: practical guide for analytical chemists, Springer, New York, 1997. |