The values of the diagnostic ratio (Fig. 2) showed the efficiency of a plasma power of 1400W. All the nebulizer gas flows for both the plasma viewings tested produced higher diagnostic ratios with 1400W than 1300W power. The values of the Mg(II) 280.270 nm/Mg(I) 285.213nm line intensity ratio varied from 0.4 to 13.4 when nebulizer gas flow varied between 0.5 and 1.1 Lmin−1. According to the values, robust plasma conditions can be obtained with a nebulizer gas flowof 0.6 Lmin−1 and a plasma power of 1400W for radially viewed plasma only. The measurement of digested ash samples with an axially viewed plasma cannot be performed under robust plasma conditions.