Synthesis of the new 2-[6-Carboxy-2-Benzothiazolylazo]-4- nitro phenol organic Reagent to spectrophotometric determination of aluminium (III)

A new 2-[6-Carboxy-2-benzothiazolylazo]-4-nitro phenol (CBTANP) organic reagent wassynthesized. A sensitive and selective spectrophotometric method was proposed for the rapid determination of Al(III) using (CBTANP) reagent .The reaction between Al(III) and (CBTANP) reagent is instantaneous at pH=8.0 and the absorbance remains stable for over 24 hrs. The Method allows for the determination of Al(III) between the range (0.02-2.5) μg.ml- 1,with molar absorptivity of (9.76 x 10+3)l.mol -1.cm-1 and a detection limit of 0.015 μg.ml- 1.Recovery and relative error values of precision and accuracy of method were found to be R.S.D=1.4% , Re=98.0% , and Erel =-2.0 % . The properties of complex was studied and show;(M:R) ratio was 1:2 at pH=8.0 ,and the stability constant of 1.228 x 10+10 L2.mol-2 . The interferences was studied of ions (Ni2+ , Ag+, CrO4 2- , Fe+3,Ca2+ , pb2+,Cu+2,WO4 -2,MO4 -2, Hg+2,Co2+ , Mg2+ , Cd2+, Ba2+ , Bi3+, Zn+2,Mn+2) and masking agents effect on absorbance were studied .