By use crown ether DB18C6 and from acidic HCl media extracted Fe3+ ion as ion association complex
by application cloud point extraction methodology after change Fe3+ into FeCl4
-, this study show 1.2M HCl
was the optimum concentration in precence 5×10 -2 M NaCl and 1×10-4 M Crown ether DB18C6 as well as
show 0.5mL of Nonionic surfactant 1% TritonX-100 was necessary to obtained higher extraction
efficiency, so that thermodynamic study illustrate 85ºC was favorable temperature for extraction
according to CPE method in addition to needing heating the solution in electrostatic water bath at 85 ºC
for 15 minutes . Thermodynamic data was ΔHex=0.159 kJ mol-1 , ΔGex=-62.43 kJ mol-1 , ΔSex=174.83J mol-1
K-1, experimental application offer the more probable stracture of ion pair association complex extracted
was [Na DB18C6]+; FeCl4
- , there are another empirical application for this study in real samples .