The Hg content
was then calculated automatically by the software of the
instrument that carried a non-linear
fit of the calibration data.
The regression equation obtained for the low-level mercury curve
was: Absorbance = 0.0629 (x)
0.0011 (x2); while the regression
equation for the high-level mercury curve was: Absorbance =
5.454
104 + 9.180
104(x) – 2.448
107(x2), where “x” is the
Hg concentration in ng. The correlation coefficient (R2) for curves
both in the low and high range was higher than 0.999, which is
considered an acceptable
fit with good linearity.