Direct, sensitive determination of trace amounts of dissolved ferric iron in natural water by light absorption ratio variation spectrometry.
The chromophore eriochrome cyanine R (ECR) was used to sensitively coordinate Al(II) and Fe(II) in the presence of cetylpyridinium chloride (CPC) at pH 4.8. Trace amounts of Fe(III) can displace Al(III) from the Al(ECR)(CPC) ternary complex to form the Fe(ECR)(CPC) complex. The composition of the complexes was determined by the break point approach. The competitive displacement complexation was sensitive and highly selective, even if no masking reagent was added. An ongoing novel spectrophotometry, named the light-absorption ratio variation approach, was applied to the direct determination of Fe(III) in natural water with recovery between 92.5 and 106%. The detection limit was only 9 ng/mL Fe(III).
Gao
Hong-Wen
HW
Tongji University, Key Laboratory of Yangtze Water Environment of Ministry of Education, College of Environmental Science and Engineering, Shanghai-200092, People's Republic of China. hwgao@mail.tongji.edu.cn
Chen
Ling
L
Yang
Qiao-Zhi
QZ
D001557:Benzenesulfonates / Q000032:analysis; D002138:Calibration; D002594:Cetylpyridinium / Q000032:analysis; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D007477:Ions; D007501:Iron / Q000032:analysis* / Q000737:chemistry; D013053:Spectrophotometry / Q000379:methods*; D013997:Time Factors; D014867:Water / Q000032:analysis*
D001557:Benzenesulfonates; D007477:Ions; D014867:Water; C010332:solochrome cyanine R; D002594:Cetylpyridinium; D007501:Iron