Important parameters such as the linear dynamic range,
correlation coefficient, reproducibility, detection limit and
enrichment factor were determined to evaluate the method
performance. The calibration graph was linear in the Ag(I)
concentration range of 1–100 ng mL1, with the equation
A = 2.8 103C (ng mL1) + 0.0123 and correlation coefficient
(r) of 0.9991. The detection limit, based on the average blank
signal plus three times its standard deviations (n = 8), was found
to be 0.41 ng mL1. The relative standard deviation (RSD) for
eight replicate extractions and measurements of 50 and
75 ng mL1 of Ag(I) ions was 3.10% and 2.33%, respectively.
The enrichment factor for the suggested DLLME method is 35,
as obtained based on the slope ratio of calibration curve after
and before extraction