Vol. 10, No 1, 2012 pp. 27 - 36
DOI 10.2298/FUPCT1201027A
UDC 546.723 : 535.243
NEW OXIDATIVE ELECTROPHILIC COUPLING REACTIONS AND THEIR APPLICATION TO SPECTROPHOTOMETRIC DETERMINATION OF IRON(III) IN ENVIRONMENTAL WATERS, SOILS AND INDUSTRIAL EFFLUENT SAMPLES
Riyad Ahmed Al Okab*, Mansou S. Abdul Galil
Chemistry Department, Faculty of Applied Science, Taiz University, Taiz,Yemen
E-mail: mansour0498@yahoo.com
Abstract.New oxidative electrophilic coupling reagents, 2-amino-2′,5-dichlorobenzophenone (MCB) or 2-amino-5-chloro-2'-fluorobenzophenone (MFB) are exploited for the determination of trace concentrations of iron(III) in environmental water and soil samples.
The methods were based on oxidation of the electrophilic coupling reagents, 2-amino-2′,5-dichlorobenzophenone (MCB) or 2-amino-5-chloro-2'-fluorobenzophenone (MFB) by iron(III) and coupling with phenoxazine (PNZ) in acidic medium to yield red color derivative having an absorbance maximum at 520 nm, which is stable up to 12 h. Beer’s law are obeyed for iron in the concentration ranges 0.31-1.2121 μgmL-1 and 0.42-1.41 μgmL-1, respectively. The optimum reaction conditions and other important analytical parameters were established. Interference due to various non-target ions was also investigated. The developed methods were applied to the analysis of iron(III) in various matrices. The performance of developed methods were evaluated in terms of Student’s t-test and variance ratio F-test that indicate the significance of developed methods over reported method.
Key words: spectrophotometry, iron(III), phenoxazines, environmental samples, soil
NOVA OKSIDATIVNA ELEKTROFILNA KUPLOVANJA I NJIHOVA PRIMENA ZA SPEKTROFOTOMETRIJSKO ODREĐIVANJE GVOŽĐA U VODAMA, ZEMLJIŠTU I INDUSTRIJSKIM OTPADNIM UZORCIMA
Razvijena je i validirana metoda određivanja tragova jona gvožđa(III) u uzorcima vode i zemljišta pomoću oksidacionih elektrofilnih kuplujućih reagenasa, 2-amino-2’,5-dihlorbenzofenona (MCB) ili 2-amino-5-hlor-2’-fluorbenzofenona (MFB).
Metode su zasnovane na reakciji oksidacije elektrofilnih kuplujućih reagenasa, 2-amino-2’,5-dihlorbenzofenona (MCB) ili 2-amino-5-hlor-2’-fluorbenzofenona (MFB) jonima gvožđa(III), nakon čega sledi kuplovanje sa fenoksazinom (PNZ) u kiseloj sredini, pri čemu se dobiva proizvod crvene boje, koja je stabilna do 12 h, sa maksimumom absorbance na 520 nm. Beer-ov zakon važi u oblasti koncentracija gvožđa 0,31-1,2121 μgmL-1 i 0,42-1,41 μgmL-1, redom za ove dve metode. Optimizovani su uslovi reakcije i ispitana je mogućnost inetrferencije sa ostalim, neciljnim jonima. Ova metoda se može primeniti za analizu gvožđa(III) u različitim uzorcima. Razultati Studentovog t-testa kao i F-testa ukazuju na prednosti razvijene metode u odnosu na prethodno publikovane.
Ključne reči: spektrofotometrija, gvožđe(III), fenoksazini, realni uzorci, zemljište
