Under the optimized conditions, the calibration graph was linear over the range of 0.1 –0.9 mgL-1 with a correlation coefficient (R2) of 0.9999. The observed relative standard deviation was 1.9%
(0.06 mgg-1, n=11).The limit of detection calculated from three time of the standard deviation of the blank was 2.9 x 10-3 mgL-1(n = 15) and the limit of quantitation was 9.6 x 10 - 3mgL-1(n = 15).
The recovery of 98.9-1.9% (0.06 mgg-1, n=11) was achieved.