tration by area (x) and peak height (y) (with the
PRM-6) showed a good correlation (r = 0.995), and the
relation is expressed by the equation y = 1.02 x + 2.27.
The peak height measurement gave a small but constant
greater concentration (Figure 4). Accordingly, the
technique of standard addition combined with area
determination may be preferred.
Table 2 shows the analytical precision at different
concentrations of urine cadmium. As can be seen in
Table 3, the analytical recovery of cadmium added to
five different urines was 96 to 101% (mean, 98.4%).
The detection limit was 1.2 nmol/liter when calculated
with the formula (2 X SD X Cd concn)iı when 12
injections of a diluted sample of urine low in cadmium