For this study, firstly Ag(I) standard solution (0.12 mg L
500 mL of 0.1% 8-hydroxyquinoline, 5 mL of CH3COOH/
CH3COONH4buffer solution (pH 6.0) was transferred to a 10-mL
calibrated conical tube. The sample solution was diluted to 10 mL
with distilled water. A mixture was prepared from 400 mL of
chloroform and 1600 mL of ethanol and then the mixture was
injected rapidly into the sample solution, in the temperature range
of 5–10 8C on a circulating water bath cooled by ice-pieces. The
Ag(I) reacted with the chelating agent to form hydrophobic
complex which could be extracted into the dispersed fine droplets
of the extraction solvent. After this stage, the centrifugation was
made to collect the dispersed droplets at the bottom of the conical
tube at 3000 rpm for 10 min. Then, 300 mL of the extractant
(CHCl3) was introduced rapidly to the nebulizer by means of a
syringe. A blank submitted to the same procedure was measured
synchronically to the samples and calibration solution