In HPLC-AAS or HPLC-ICP hyphenated techniques the sample volume is determined by the volume of the HPLC loop in every day practice. This volume is generally 20-50 μl. By using these small sample volumes the detection limits of atomic absorption or emission detector are worse than in the case of the normal high volume introduction mode. The solving of this problem is very easy: we have to use larger loops for sample introduction. But what loop size is optimal? In this article we use a parameter for calculation of optimal sample volume. This parameter is the theoretical tank volume of ICP or AAS nebulizer chambers. A very simple method is described for the measurement of this parameter. Six instruments were studied in our experiments. The theoretical tank volume of nebulizers were found to be very different. The values were between 20 and 400 μl, depending on the instrument. On this basis the optimal sample values are between 60 and 80 μl, 150 and 300 μl, and 600 and 1300 μl for AAS, ICP, and hydride-AAS, respectively.
ASJC Scopus subject areas
- Analytical Chemistry