PORTUGALIAE ELECTROCHIMICA ACTA ! "# $ % " # $ ! %&% ' ( ) ! & * ! + ,! & ! $ ' ! " " $ %& #" !( , 1 2$ %& !) µ *+ ! µ *+ -*.µ *+/! ( #" " 0! - , #" 0 , & &' !) µ *+ ! µ *+, !) µ *+! ( 0 ! µ *+ 12 " -*.µ *+/, " ! µ *+ 3 ! µ * , ! µ *+, ! , , , 40 , ! ( ) + 5 5 6 " " 8 , % , %" 9 : 6 " , µ * + ? % 6 , #" % ,1, " " ! =2 @ 7A 7 , 6 ; 2 <! = > " , !" ! ! 5 , &, 5 % , > %-% # ./ 0!+% 1 2 / , 03 #" #" " " , , 6 " B 7 : , " 6 " " , > #" B & " , 5 " B : ! = #" > 5 5 " " " 7 5 7 5 #" 6 %, 1 ! 8 B 5 B 5 7 #" , 7 " : 7 ! = #" " 7 : 2 > " , , , 7 /232 7 2 , 26 2 2 , : 2.32 , 2 2 , #" " ; 2C<! 6 " 5 " 5 7 µ * +" 7 , : $ %& 2 & &' , , 5 D " 7 ;E<, ; <, B B " , B " , 6 "6 5 5 5 " 7 5 #" 1 2 %&! * ( :" 7 0 *, " , > " " 7 " 6 7 F G&' " #" " 76 : H " 8 J 4 H " " 6 " B 6 " , I! = #" " " " 7 =DKD, " " >, " %-% # ./ 0!+% 1 2 / 03 " - * - %! " " 76 6 ," 7 5 6 " 6 , 1% " J! $ %& & &' , , B #" " " " " ! " != B 6 " 7 B , " , 6 #" , ! ( : B F " 6 µ * + 5 L ( + ( " B 6 5 ! - B , : 6 5 5 " " 5 B ; <, 6 " 7 0 " 6 " 6 ! ( ) @ , ! + > , 2 2 " " > " " 6 ," 7 6 6 , " 5 6 6 " F 6 ! - ! + B > 1 2 %&2 " " 5 > &' 2, 6 " " ! %" " " " F 3 )!) - ! *+ " & &' , 2 B #" " > 6 µ * + - != " > 6 : $ %& F B 6 *+, " 76 " : 5 " " " #" 1 1, #" 12 1 2 %&2! = > #" 6" F M ,)3 N, %-% # ./ 0!+% 1 2 / 03 6 " 6 #" " 1, #" " 6 " 7 " 6 5! 6 %&2 > " 5 > 6 B 5 " 5 6 ! 3 % - . 3 3 3 3 )3 3 ) 3 , % - . / , 3 % 3= " -/. * + & &' & $( ) * + , 3 , 0 012 - $, . µ *+ 1 , $ %&! O F ! , 6 - ., ! *+ G'- , ! %-% # ./ 0!+% " 1 2 / 03 B F 5 > " : " ! 6 " 7 B *+ %G %''G ! @ $ %& ! B D ;< ! 8 > " " , 3 " " F , " " " " , " " 6 " " 5 B " != B - E N*, " , 6 B , " N*! 6 " " ! 1 E !4 - , 6 " 3 N " " 6 ! = #" ! " F F > " M , 4 N N* , " != " 6 ,3 "6 " 6 C! , B 1 ! H, #" " " F B - *- % . /! F " " : N* O F 7 ! 6 ! = " B H, 1 " , " #" > 1 ! - 6 , * +, & &' B " " " * +! > 6 " 7 " 3 " , D N* " ;E< 6 %-% # ./ 0!+% 1 2 ' 3P 1* $ %&! / " 6 ' 4 ' , -µ$, .E) !3 3 4 EE) E 3!3 , 3 ( 5 6 4 " N #" 03 % ) . !CC) !CC4 !CC !CC3 " N 6 6 " 6 #" " , " N, 1 ! ! E % - . 4 0 25 50 75 ( & $( 2 = " ! " ( " * + - 125 " * + & &' G'- , ! F ! µ *+ 1 O, * + $ %&! " & &' ! % $ %& 1 ! -, " ! ) : 150 . " : ! 4 * + 6 $ %& 1 ! H, 6 & &' ! ! > 6 $ %& *+ ! #" 100 * + F " , ! *+ 1 " , %-% # ./ 0!+% ! 6 7 B " " 1 2 / B 03 G B 5 " !" ! * + B , " , F B " 1 " " > G 6" 7 & 'G B 5 #" %G %''G F ," 7 5 , ! % - . 3 ! ! % ! E ) 4%0 - ! 4 ,. % - . / , 3 % & $( 5 = : -/. 6 N! F , ) 0 012 - 6 $ %& µ *+ 1 O, , 3 , 3 , ,. -. ! N* " " & &' * + G'- , " %-% # ./ 0!+% 6 1 2 / 03 B 5 µ * +! = 6 ' B 1 ! 6 #" " " " 1! B F : 1* $ %& 6 5 " #" " 6 , L ( , " + ! 6 " 7 -* .µ * +/ : , #" " @ " 7 & &' #" " " 6 -* .µ * +/ E > !E -* .µ * +/ > , -*.µ * +/, 3 4 " 6 -* µ *+, E 3 #" E)C ! " 6 B + 3 - . -*.µ * +/! 4 E Q E 3, O E) ,3 % Q ,CCE E % & $( 6 %" * + & &' ! N* " " ) 6 & -($, . B *+ " 4 1 $ %&, N! ! 6 E * + , G'- , ! %-% # ./ 0!+% 1 2 ' 2 +: / 6 03 " 6 1 2$ %& & &' ! ) µ$, 6 % % P 4 ,1 %4 +: +: * 8 B ! ) ! 0 ! µ *+ !) µ *+ > " ! µ *+ 6 * %!N! 0 8 !CC 4 ! C ! ! 3!) 3!E " " D" 6 5 " )! *+! ( 7 6 G ' 6 " !( B " ) ! µ * + L " P 8 , " ! 6 G&' ! P " 6 5 ) N H G" 7 $ %& F G% ' ! = !)! ," 7 #" " " " B " G% ' !( , " " " G&' G% 6 " 6 " @ " " " 5 + 7 " 7 L ! " ! " 5 B ; <, ( ) 3µ$, " + % "7 = 1 2$ %& 6 7 " O ) 5 7 1 % ' ,-µ$, . 4E C C 8 6 B 6 +7 , -µ$, . % 6 E! 0 ' 6 6 " ' 58 & &' ! = , P F : ! + "6 B 3, %-% # ./ 0!+% ! 1 2 03 = #" > 12 3H, / > " 3! " 6 12 ! * ( &, 94%0 & , 8 !- * - % 8 ( 6 ( #" - " 2 ! N 2 ! 2 !) N 2 !E3 N N N N* 8 2 ! 4 N F 5 C? 6 ; ' 3 N* 2 ! E N 12 * +! , " 3 µ *+ ! µ *+ ) ( % 2 N µ *+ & < N 4 " : 8 B G E!4 < 1 ! 3, 1 2$ %&, ' #" " 7 , B ' 6! 8 B $ %& 1 2 5 ! µ *+ ) ) + ( ) µ *+ ) 8 !3 µ *+ ) CC µ *+ 3 ) !4 )!) 4 % 8 !4 4 ' , -µ$, . !)) ! !EC E!C !4) %-% # ./ 0!+% 1 2 / 03 60 y = 3,5663x + 10,38 R2 = 0,9984 Corriente (nA) 50 40 30 20 10 0 0 2 4 6 8 10 12 Concentración de Fe (ug/L) / - . Q , O , C Q ,CC 4 % E 3 % & $( :! %" G'- * & 'B % 6 G E!4, µ *+- . ) B & -($, . 1 ! 3 N* " 3 µ *+ 3 µ * +-/.! E " * + , N, ( % " " 6 : " = " 5 : 7 7 ! #" " 7 B : #" 1 2$ %& #" 6 " & &' 12 6 , > C ! B B B > " %-% # ./ 0!+% 1 2 " > " L / 03 : 6 " 6 : ! $ % % N #": = : = 6 , = " .%=+=I/ 6 : I": 6 I": R 6 ! ) ( 7 7 = $( 1 + ( 6" " 5 " 6 6 " 6 " 7 $ %& & &' : ! = 5 " B !) µ *+ ! µ *+, " : 6 ! µ *+ " 6 !) µ *+! + -* .µ *+/! + 0 " 6 ! µ *+ " 6 0! ( 5 " 6 12 , " -* .µ *+/ #" 1 2$ %& " B , ! µ *+ 3 ! µ * +, " : 6 !) µ *+ " 6 ! µ * + " 6 40 " 0 6 ! " : " 76 ! @ : 5 : , , , , , B 7 ! + ! ! +! - , -!+! - 7 6 E2 $! ! S! T ! H , 5 6 , ! H , 5 6 . CCE/4 ! :, -!+! - 7 6 , 32 . CC3/ ! , 11 ! 1 !5 N%G 8" , C43! ! %! !D! N H , 9!I! G" , +% 3! %! !D! N H , , '! - . CC / ))! !& 11 % , =! ! )) . C4 / EC! , ! %-% # ./ 0!+% 1 2 E! 9! D , $! ! )! S! T , ! 4! 9! 9 , T ! S , +% C! !D! 8 , 7 , 03 . CCE/) )! , , -! N " ! S!$! ( 8" ,8 / ! C4)! . C4C/E ! % " , ! E) . C4C/ ) ! 3 . CC / 33! * , +