Abstract
A novel optical sensor (optode) is described for the determination of thiocyanate using methyltrioctylammonium chloride immobilized on triacetylcellulose membrane. The response to thiocyanate is the result of adsorption of [Co(SCN)4]2− on sensing membrane, which caused the colorless membrane to change to blue. This optode can readily be regenerated by using 0.02 mol/l sodium oxalate solution. The linear range of the method was 3.44×10−5 to 8.61×10−4 mol/l of thiocyanate with a limit of detection 1.51×10−5 mol/l. The relative standard deviation for eight replicate measurements of 8.61×10−5 and 4.30×10−4 mol/l of thiocyanate was 3.45 and 1.23%, respectively. The sensor was successfully applied for the determination of thiocyanate in saliva of smokers, nonsmokers and various water samples.
The authors are grateful to Shahid Chamran University Research Councils for financial support.