Calibration was performed under optimized conditions with standard solutions with concentrations that ranged from 0 ngmL1 to 100 ngmL1 with respect to copper(II).For each
standard solution,three replicate measurements were performed.The calibration data were evaluated by linear regression analysis using the Excel software package.The limit of detection and limit of quantification were determined via the 3 S/N and 10 S/N
methods, which reflect the concentrations of copper(II)that produced signals that exceeded three times and ten times the blank signal,respectively.The precision of the peak heights was estimated by performing 10 replicate measurements of standard
solutions that contained 0.5,5.0 and 30.0 ngmL1 of copper(II).