selectivity coefficients of ion-selective electrodes - iupac

Pure & Appl. Chem., Vol.51, pp.1913—198O.

0033—4545/79/0901—1913 $02.00/0

Pergamon Press Ltd. 1979. Printed in Great Britain.

©IUPAC

INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY ANALYTICAL CHEMISTRY DIVISION COMMISSION ON ELECTROANALYTICAL CHEMISTRY*

SELECTIVITY COEFFICIENTS OF ION-SELECTIVE ELECTRODES Prepared for publication by E. PUNGOR, K. TOTH and A. HRABECZY-PALL Technical University, Budapest, Hungary

*Membership of the Commission during the preparation of the report (1975-1977) was as follows:

R. 0. BATES (Titular Member and Chairman; USA) J. F. COETZEE (Titular Member and Secretary; USA) E. BISHOP (Titular Member; UK) T. FUJINAGA (Titular Member; Japan) Z. GALUS (Titular Member; Poland) J. JORDAN (Titular Member; USA) H. W. NURNBERG (Titular Member; Federal Republic of Germany) P. ZUMAN (Titular Member; USA) M. BRANICA (Associate Member; Yugoslavia) A. K. COVINGTON (Associate Member; UK) L. GIERST (Associate Member; Belgium) K. IZUTSU (Associate Member; Japan) L. MEITES (Associate Member; USA) E. PUNGOR (Associate Member; Hungary) 0. A. SONGINA (Associate Member; USSR) B. TREMILLON (Associate Member; France) D. D. PERRIN National Representative; Australia) G. KRAFT (National Representative; Federal Republic of Germany) R. C. KAPOOR (National Representative; India) N. TANAKA (National Representative; Japan) W. KEMULA (National Representative; Poland) P.O. KANE (National Representative; UK)

SELECTIVITY COEFFICIENTS OF ION-SELECTIVE ELECTRODES

E.Pungor, K.Tôth, A.Hrabéczy-Páll Institute for General and Analytical Chemistry, Technical University, Budapest, Hungary

Abstract - In the present paper, after a short introduction including the difinition of the potentiometric selectivity coefficient and an outline of the methods used for its determination, selectivity coefficient data are collected in form of a table. In addition to the actual numerical values, the type of electrode and method and conditions used in the determination of the selectivity coefficient data are given in the table. THEORETICAL CONSIDERATIONS Ion-selective electrodes are characterized by parameters such as the slope of the potential response, selectivity coefficient, detection limit in unbuffered solutions, exchange current, response time etc. Among them, one of the most important is the selectivity coefficient of the electrode, on the basis of which the potential application of an electrode in a given system can be predicted. The selectivity coefficient is defined by the Nikolsky equation as follows: E = E0 + 2,303 RT log /a. + 1 z.F 1

where

V' K? j j L. 13 j=l a.

/

is the potential of the electrode E° is the standard potential of the electrode z. and z. are the charges on ions i and j, respectively /irefers to the primary ion, for which the electrode is designed and j to the interfering ion! a. and a. are the activities of ions i and j, respectively, and E

K?t is the selectivity coefficient of the electrode in the presence

ofionj. In general, the selectivity coefficient Kt can be expressed as follows:

K?t = K.. 1J

where

K..

f/u/

.

1J

f/ui

is the equilibrium constant of the reaction determining the electrode response in the presence of ions i and j /e.g. precipitate - exchange reaction, complex - forming reaction or extraction! is the function of the mobilities of ions i and j within the electrode membrane; it is equal to unity if only surface equilibrium reaction is involved.

Consequently, for precipitate-based electrodes /also referred to as crystal, single crystal or solid—state electrodes/, when only surface exchange reactions take place,

K?t = 1]

K..

13

1915

COMMISSION ON ELECTROANALYTICAL CHEMISTRY

1916

that is, Kt is equal to the equilibrium constant of the exchange reaction between thelectrode membrane material and the ion j in solution, i.e. to the equilibrium constant of the precipitateexchange reaction. This theoretically can be expressed as the ratio of the solubility products of the electrode material IS.! and that of the precipitate formed in the exchange reaction /S/, if monvalent ions form the precipitates:

KP0t — ii

Si S. J

This offers a possibility for the theoretical calculation of selectivity coefficients for precipitate—based electrodes. However, in other cases there is no way for the theoretical calculation of the selectivity coefficient since it involves ion mobilities within the membrane which can not be determined exactly.

MEASURING TECHNIQUES Selectivity coefficients can be measured by different methods which fall into two main groups, namely 1. Separate - solution techniques 2. Mixed-solution techniques 1. In using the separate-solution techniques, the potential of the electrode studied is measured with the same potentiometric cell in solutions containing the primary ion and the interfering ion separately. From the electrode potentials measured, E. = E 1

= E

E j

o

o

+

2,3O3RT z.F 1

+

2,3O3RT log KP0t z.F ija.

log

a.

1

3

J

Kt can be calculated either with the so called equal activity or with the equal potential method. In both cases it is tacitly assumed that the electrode standard potentials are equal in the presence of ion I as well as in that of ion j and also that the response is Nernstian for both ions. According to the method of equal activities, the solutions of ion I and j are prepared at the same concentration and the potentiometric measurements are carried out. From the measured potential values fE. and E./ the selectivity coefficient can be calculated. For cations of the ame vaency the following equation holds: E. - E. 3

1=logKPOt 13

2,303RT

At

the method of equal potentials electrode potential measurements are made in two series of solutions containing the ion I and j separately. From the results two calibration graphs are constructed. The selectivity coefficient is then calculated from the activities of ions i and j corresponding to equal potentials as follows:

K?t= 1J

a.

1

a.

Z.

3

The separate-solution technique for determining selectivity coefficients is simple and allows a number of KP0t values to be measured on the basis of ij

Selectivity coefficients of ion—selective electrodes

1917

different activities and potentials. However, the result may be different depending on the activity and potential values used for the calculation and furtheron, they may be erroneous since the assumptions mentioned are not always true. Furthermore, in practical applications the primary and interfering ions are present simultaneously and the electrode may behave quite differently under the simultaneous effect of more ions than when the ions are present alone. Thus, the conditions of separate solution measurements do not resemble those prevailing in the actual measurements with ion—selective electrodes.

2. In the mixed-solution techniques, the electrode potentials are measured in solutions containing both the primery and the interfering ions. The method can be realized in two ways, by potentiometric direct or indirect /titration/ method. In the direct method a series of solutions is prepared in which either the concentration of the ion i is kept at a constant low value and that of the ion j is varied, or the concentration of the ion j is kept at a constant high value and that of the ion i is varied. Another approach of the latter is based on exponential dilution and is suitable for continuous measurement. The method is realized as follows: A container of constant volume contains a solution in which both the primary and the interfering ion are present in a relatively high concentration. This solution is diluted continuously at a constant flow rate with a solution of the ion j having the same concentration as that in the container, and a potential vs. time curve is recorded. /As a result, a curve consisting of two linear parts is obtained. / By rescaling the time axis a potential vs. - log a. plot is obtained. Applying the mixed-solution method, tI\e electrode potential is plotted against the varied ion concentration. The plot is generally composed of two straight lines.

If the selectivity coefficient of the electrode studied differs very much from unity /it is less than 10-6/, then the potentiometric indirect, titration method should be employed for its determination. As titrant, a soluble salt of the counter ion of the precipitate built into the membrane is used. For example, if the chloride ion selectivity of a silver iodide-based iodide ion—selective electrode is intended to be determined, then a olution containing chloride and iodide in the same concentration /e.g. l0M/ is titrated with silver nitrate solution and a titration curve is recorded using an iodide ion-selective and a reference electrode. The titration curve usually has two break points, the first corresponding to the titration of iodide and the second to that of the chloride. The concentration of the iodide ion is calculated forthecoprecipitation point considering the initial concentration of the iodide, the potential jump and the Nernstian response of the electrode, while the concentration of the chloride is equal to that originally present. Accordingly, this can be considered as a variety of the mixed-solution method where the concentration of the primary ion is varied while that of the interfering ion is constant. It should also be emphasized that this method yields only an approximate value for KPOt. iJ

CALCULATION OF THE SELECTIVITY COEFFICIENT At the mixed—solution methods the selectivity coefficient is calculated from the activities of the ions at the break point /B/ as follows: z.

KP0t ij

/a i'B z.

/a/B It may be mentioned here that if, at the mixed-solution method, the concentration of the ion j is constant and that of the ion i is varied, then the second straight line /that parallel to the abscissa! does not always show up. Since in the meaning of the selectivity coefficient it is involved that the effect of both ions at the break point is the same, the break point is located at a distance of 18 mV from the extrapolation of the upper straight line. This offers possibilities for determining the selectivity coefficient

1918


even if the second straight line can not be observed on the plot. In conclusion it must be pointed out that the selectivity coefficient data depend to a great extent on the method used for the determination and also on the concentration level of the primary as well as the interfering ion, and on the nature of the electrode membrane. Best agreement between selectivity coefficient data determined by different methods under different conditions is expected and found in the case of precipitate-based electrodes.

The following survey on selectivity data contains the electrode type, the method and conditions of measurement if available and the reference. The electrodes are listed in the following order: simple anions simple cations composite and organic ions and molecules In the Table i always refers to the ion or molecule measured while j to the means the pOtentiometric selectivity coefficient. interfering ones, and

SUGGESTED LITERATURE A.E.Pungor, K.Tóth:. Selectivity of ion-specific membrane electrodes, Anal.Chim.Acta 47, 291. /1969/ B.K.Srinivasan, G.A.Rechnitz: Anal.Chem. 41, 1203 /1969/ C.G.J.Moody, J.D.R.Thomas: Selective ion sensitive electrodes, Merrow Publishing Co. Ltd. Watford, Herts, England, 1971. D.P.L.Bailey: Analysis with ion-selective electrodes, London, New York, Rheine, 1976.

Selectivity coefficients of ion-selective electrodes

Table

Ion or molecule measured

1919

Selectivity coefficient data

Type of electrode

Interfering ion or molecule

LaF3 single

OH

crystal

Cl

K. .

Method

Experimental Ref. conditions

101

pH 4,5

90

NO3 HCO3

SO LaF3 single

OH

crystal

I Br

Cl LaF3 single

Cl

crystal

Br

}1010/

HgS/AgI

Cl

108

precipitate

Br

106

I

/1/.

SCN

106 1>1010/

HgS/Hg212

precipitate

Cl

io0

Br

1010

I

/1/

SCN

1010

92

cl03 pH 11,5

125


1930

Ion or Type of molecule electrode measured


K..

Method

Experimental conditions

Ref.

.

/ > l0/ SCN

homogeneous

I Br

Cl

SCN

Ag2S/AgSCN

17

/ii013/

AgSCN/Ag2S

/lo/ /2/ lo

CN

102

OH

lO

F

l0

Cl

102

Br

11-

pH 2,5 c 1=1O3M

1> 1010/

c varied

I

125

/ > 1010 HgS /AgSCN

Cl

io2

Br

/10/

I

HgS+Hg2 /SCN/2

/>1010/

Cl

1o2

Br

iio2/

I

/lob0/ SCN

coated wire

Cl

/Aliquat

NO3

336 S/

SCN

precipitate in

SO-

mixed

c.=lO3

solution

—

4,6.102

l0

I

3,4.101

Cl

/2,8—3/ .lO

c varied

mixed

thermoplastic matrix /AgSCN

in polythene/

4.lO

c=lO5lO4M

solution

Br

I

/1—1,4/

/1,

58

74 ,7 102

c=lO1M c=lO5—lO3M c=1O3M c=lO5-lO3M c .=lO5M J

SCN

ion-association

C1O4

/12/

extraction sys-

104

/6,7/

tem /crystal

I

0,34

54

1931



violet in nitrobenzene /


K.. 1J

Cl03

5.102

NO3

3.102

Br

Br03

Method


Ref.

6.lO 2.lO

Cl H2P0'

lO

OAc

S0Ag2S precipi-

I

1,3,1015

tate based

Br

5,0.1023

heterogeneous

Cl

1027

/

SRI

c .

4,0.1032

=lO2M

}

separate

Ag2S precipi-

tate based

SO

and

homogeneous

SO-

mixed

/Orion/

CO

solution

HCO3 I

101

70

l0

Cl

1M NaOH

Br

c .

F

c .=101-lO2M

1

=l01-lO2M

3

CN 2+

Hg Ag2S precipi-

Cl

tate based

Br

heterogeneous

I

/thermoplas-

CN

tic matrix/

520 Na

8.102 75

L08—l0

+

Ca2+ 2+

Mg

Pb2 Cu

2+

105_106

1932




Hg S2—

2+

Method

K..

Ref.

102

Ag2S preci-

I

l,6.lO*8

pitate based

Br

2,5.1012

heterogeneous

Cl

6,3.1015

/SR/

OH

6,3.1017

SCN

8,0.1013

Ag2S preci-


titration

C=lO1-l02M

122

( 1021

SO P0

8,0.1017

Tl

6,3.1025

Cu2 Pb2 Cd2 Ni2 Zn2 Fe2 Mn2 La3

2,0.l0

CN

6,3.lO

S2O

2,0.10

l,6.l022 4,0.1023 5,O.1024 1,3.1028

.

3,2.1022

.

6,3.lO 5,0.1041 11

Cl

1

pitate /Crytur I Br

i

lo8lo0

CN 2— s203

Na+

K Ca2

l05_106

Mg

2+ .

Pb2 .

Cu2+ Ag2S precipi-

Cl

3.10.31

separate

tate/Crytur/

Br

5.1026

solution

I

2.1018

OH

8.. 1027

140

1933


Ionôr Type of molecule electrode measured


Method

K.

Cl

7. lO calculated

Br

2.1O26 from solu-

I

8.lO bility

OH

p%J

lO

Ag2S

I

lO

homogeneous

Br

1013

Cl

1015

SCN

1013


Ref.

products 17

CN OH F C1O4

liquid ion

I

exchanger

NO3

2.lO

-lOs

/Orion/

Br

6.lO'

pH 4-11

F

3.lO 2.lO

Cl

C1O4

C104

1016 1,2.101

CC10 _lOl

liquid ion

I

2,89.102 mixed

exchanger

NO3

4,29.1O solution I=O,lM

/Orion/

OAc

1,65.1O

Br

l,O7.1O

HCO3

8,82.1c14

F

2,88.lO

I

, 0,016-0,071 separate jc=1O -

liquid ion

cClOlO3

—1

solution

exchanger

69

48

132

1oi

/Orion/ I

0,023-0,020 mixed solution

c1=0, l-O,O5M

cC1OO, 002- O,007M

C104

ion exchanger

NO3

Fe/Phen/3/Cl04/2 I_

1,O.lO 5,9.lO

in nitroben— zene R4N.C1O4

NO3

2,9 .1O3

52

1934



Interfering . ion or molecule

NO3

4,3.lO

I

2,9.102

Ni/Phen/3/Cl04/2 I

1,3.102

I

3,2.102

I

1,1.101

solid ion

F

4,2.lO separate

c=lO1M

exchanger

Cl

7,8.1O solution

unbuffered

on Selectrode

Br

6,5.lO

solution

body

I

Cd/Phen/3/C1O4/2

/azoviolene/

NO3 OAc

3,2.l0

Cl03

8,7.lO

BF4

0,12

SO

2,3.lO

OH

6,3.lO

exchanger on

CC1O =10

i,i.1o2

1O2M

4.102

1O3M

2,1.101

1O4M

0,39

separate

Br

6,6.102

solution

NO3

1,4.102

/o-tolidine/

Cl

2.lO

/o-dianizidine/

I

0,36

Br

2.102

NO3

Cl

/1,66/

ylene

Br

3,4.102

benzidine/

NO3

2,9.102

OH

exchanger

I

j

128

9.lO

I

liquid ion

c.=c.=101M i

1,8.102

/tetrameth-

Cl

127

1,l.1O 6,3.1O

I

Ref.

/75/

OH

solid ion

Selectrode

C1O4


2,0.102

Cu/Phen/3/C1O4/2

C1O4

Method

I

Orion

C104

K

3.lO /1,0/

1,2.102

mixed solution

117

1935



Cl04


Method

K..


Ref.

130

/Orion/

NO3

l,5.lO

mixed

Fe/Phen-R/

Br

5,6.lO

solution

OAc

5,l.lO

HCO3 F

3,5.lO 2,5.lO

Cl

2,2.lO

SO

l,6.lO

I

2,4.1O2

separate

c=1O1M

azoviolene

BF4

1,2.101

solution

for SO

derivative in

OH

l,6.lO

NO3

2,O.lO

Cl03

l,8.lO

liquid

dichloro benzene

1O2M

SO

C104

ion exchanger

Br

117.101:

F

l,8.lO

OAc

4,l.lO

Cl

2,5.lO

OH

l,3.lO

2,8.10

lO1M

mixed

115

solution NaOH

/Orion/ in PVC I

5.lO

separate

c1=1O1M

solution

Br NO3 C1O4

Brilliant

Green in rubber

9.102

separate

HCO3

5.102

solution

NO3

102

Cl

8.lO 7.lO 5.lO

F

3.lO

OAc

liquid

2,9.lO

I_

Br

C104

104

7,4.102

/Methylene

I

4,8.102

blue in

SCN

4,7.102

SO

2,5.1O

nitrobenzene/

cBr=lO2M

1.106

E1

32

E2

mixed solution

cC1OO,2 - 2 mM

c=high

60

1936

COI'NISSION ON ELECTROANALYTICAL CHEMISTRY


Interfering iot or molecule


ci0= 0,2

1,3. lO

mixed

OAc

l,2.l0

solution

3

9;l.l0

•2CO3

—4 8,3.10

103

8,0.l0

Br

8,0.l0 4,8.l0 3,4.l0

OH

9,l.l0

NO3

Cl

liquid ion

Method

C lO

BrO

Cl04

K..

Ref.

-2 mM . c. = high

2,4.l0

separate

c=9,l

solution

•103M

exchanger

NO3 OAc

/perchlorate

OH

4,7.l0 4,3.lO

of tetrakis-

Cl

2,6.l0

triphenyl

HCO3

3,4.lO

phosphine

H2P04

2,9.l0

SO

2,2.lO

HPO

3,9.iO

NO3

2,8.lO

mixed

OAc

l,6.lO

solution

OH C1

8,3.lO 2,4.lO

SO

3,4.lO

143

silver /1/ / .

c=2,7.lO3M

c=91l.lO3M c. varied 1

c=217.l03M c. varied

C10

Cl

4.1O

/Aliquat 336S/ N0

2,8.1O2

coated wire

SO Cl03 NO3

1/ 1>1/

Zn

Cr3 A13 Ni2 Fe2 Co2 Mn2

cTl=1OM

134

mixed

cFe=104M

38

solution

I =

solution

1/ 0,8

2,9.10

—3

1,9.l0

l,6.1O 8,3.lO 2,O.1O

4,4.l0
1/ /

2+


1>1/

2+

Cu

1969

2+ 2+

Sr

Ba2

K

io

Li

•+

Na

+

K Rb Cs Fe

3+

Ag2SCUS

+

Cu2

2 Cu

/6 /

0,1

pH 2

101

in 6.lo3M salicylaldoxime

Ni2

5.102

mixed

Pb2

3.l0

solution

Fe2

< 2.l0

+ Na K+

cFe3+104M I =

0,1


1970


Type of electrode


Method

K.


measured

NH Ca Ba

2+ 2+

Cd2 AuCl4

liquid

Cl0

separate c=c=lO4M

33

solution

/Safranine 0

tetrachloro aurate/ Re04

liquid

ClO

0,42

separate

/Brilliant

SCN

0,11

solution

Green

NO3

0,002

ClO4

0,12

separate

SCN

0,11

solution

NO3

0,04

c=c=l02M

34

perrhenate I

Tn-

liquid

fluoro

/Crystal

Cl04 SCN

acetate

Violet!

NO3

HPO

so

1]

c.=c.=lO4M

/l,5.l0/ mixed /5,5.10/

53

solution

/1/

lO io

CH

C12COO 2,7.101 1.101 C6H5COO CH3COO

lO

/COO/

lO

I_ Br

1,4.101

Cl

8.lO

F Benzene

liquid

sulpho- /Crystal nate

Violet!

/1,8.10/

lO

Cl

3.lO

NO3

7.6.101 solution - 0,005 M

mixed

c=O5 M

phenol-4-

l,6.l02

0,005 M

disulphonate 5.lO

0,005 M

sulphonate benzene—m--

56

1971

Selectivity coefficients of ion-selective electrodes


Type of elec trode

Method

K


measured

benzoate

4.102


0,005 M

-naphthalenesulpho-

nate

0,00025M

/16/

1,3,6 naphta- 8.lo lene

c 0,005M

trisul—

phonate cx-naphthalenesul-

phonate

/

liquid

Cl

Crystal

NO3

Violet!

4.lo

mixed

c 0,5M

3.102

solution

0,005M

benzene-

sulphonate

7.102

1,5 naphtha-

lenedisulphonate

7.l0

0,005M

6.lO

O,OlM

2,5.102

O,005M

4,5.lO

0,005M

1,3,6—

naphthalenetri-

sulphonate 4-hydroxy2-naphthalene sulpho—

nate

2, 3-dihydroxy naphthalene6-sulpho-

nate

P.A.A.C. 51/9—K


1972


Type of electrode


Iso-

Coated

lauryl-

wire

Cl

benzene

/Aliquat

sO-

sulpho-

336S in

nate

PVC!

K.

Method Experimental Ref. conditions

1, 2. 102

37

6.lO 9,3.101 1

NO3

8,1. l0 5,9.10

Cl04 OAc

1

lauryl

sulphate

/1,36/

lauryl

0,81

sulphonate p- toluene

sulpho-

8-quino-

nate

0,75

Cl

5.lO

mixed

OAc

8.l0

solution

Ion pair

NO3

3.102

consisting

sO-

8. lO

liquid ion

pH = 6,5

133

line 5- sulpho- exachanger

nate

/Hqs/

[Hqs—_4. 103M

of Hqs and benzyl-

dimethyl tetradecyl ammoni urn!

lO

Maleic

liquid

Acetic

acid

/Crystal

fumaric acid

Violet in

benzoic acid

3.l02

1 ,2-dichlo-

CF3COO

3.101

roethane I

salicylic

acid

I'N 1'U1TD'IUV 'S8 /9L61/ SLI 'Sz 'a'r 'S3TAU 'f's '!pOO 'suxoqj /L61/'L6 'L8 '9Z 'M'a'r 'SeTAQ 'f'f 'W'M 'eOTtd 'SPUIOtLL'I'cI'f 'oPt'qPj __________ ,-i IEL6TI 'H'CE 'SUA5 'UI93'IUV '1717 /L6I/ '9L8 '8Z 'a 'iAa 'v'o 'Zçuqoej 'W1TD'lPU( 'E17 /1L61/ '0601 '6? 'fl 'f ')jOTZflj 3V'U1TID'IUV 'L9 IEL6I/ '6L1 'OE 's 'y' 'ZTUqO9I '17 /OL6I/ '069 'TE 'S 'A'H 'cLtog /1L61/'Ef,i'UIeqYIPUY 'SLST '?E '6f'o 's'v 'uPqP /17L61/'E/, 'ozz 'EE 'IYV '5fo 'Y'V '91'IPtIV 'EE/9L61/'6 ''y 'ffOff 'V'V '9'1'1UV /9L611'6 '6E 'SE •f'r[ 'Aeuto 'ff'f 'cOOW 'QJ 15L61/ 'LSI '9E 'S'W 'M'f 'SSOI OU8TOS_''tf 'L91 10L61/ 'L86 'LE 'J 'fUTCfl 'S 'T)[ZNO H 'iesçec 'meqD'IPUV /hL61/'9h7 'Zh81 '8E 'S'A '6Un3: 'M'>I 'fund '6hz /LL6T/ 'L6t '6E 'A'V 'A)[SAeTptOO 'UUtT4S atJ 'AO{U 'I'N 'AO[nqz''y 'I'flA 'AOSTlCfl 'WT11)I'IPUV'1Z IL6TI'LZ 'OLIZ 'Oh 'A'Y 'c)jSA9TptOD 'A'V 'AO)[ueqaxcg 'UTAAg'I'M 'S'A 'UPULX9q ''f

' ' 'ff'

'ZI

'qsax 'qsax

'a

'I'TUv

'U1e1'Uv

PUTJ

'3['

PV'WTq3'UV

'tO5 '1'5 'Ut5

'l1P3

'1eSTt 'U183'U

'SI 'M'I 'lTt3

'STt

'113

'qosat

''3 'h4 'j'[ SN

IT stn'S'/

'j'Q'f

'

'D'1UV

'-ee ';t 'O'v

utnqcoqj_'j 'surn DwT'TPuv

'TqTs-1v

'TPPqT5V

SIRUy

'Ut

'S'A

' 't ' '5 'Ef

'9I

'L '8i '6I 'OS 'IS

•t'S

•SS •9S LS 9ç

9Aiuy

POOW

'O

'L

PU1i

'weq'uj

''y

'q'Az V'WTq3'PUV 'L6I 'LS

'AOqnqzo

'UAA

'[ 'UOtOf 'fl ',t8IPeT /LL6TI •EE 'H's 'f'D 'Apoo •j'a'f 'suioqj, /3L61/ 'OZi 'W 'TfhflO 'a 'M 'UQUITS ILL6I/'16_OV'U1T4D'IUV 'LOT 'E'f 'II3tH •ci'v 'SeUOL' •I'E 'uTddoqD 'wet:D'Iuv 'Ui /6961/ '6StiI 'J 'IedeH 'w 'ojzser 'OI /LL6II 'i'n 'uuLIeH 'ziuqej /5L61/ 551 'V'M 'U'>I 'IOOd 'EZ /9L61/ 691' 'W'Jl 'fl8SH 'ZUqoaj '1 /8961/ '6Z9 v 'T)PTUIflH 'z '8L 15L611 'I9 'V 'TNDTUIflh1 'zoTMoucot 'N '1tOT3 uIP,L 'E /9L61/ 'Lt •v 'TLOTUTflfl •V lu1suaMerI PUPTJ /LL6T/ 1L1 ,i 'TqsqqsI 'tTO> 'f7 /1L61/ S8L 'TqsqqsI •y 'OAf f'W3qD010W ,--: /EL6T/ •ozz N 'qsqqsI >I IEL6TI .c1z N 'M[8w__N £L61 611 N 'TqsqjsI H 'tto> 'TqOflOUtOH P:uwEPL /EL6I/'O L98 'icpoow 'SWOLLIU'f /9L61/'TOT 6L1 H 'SU1f '4OULt3'S H '99T3t •meq3.-[Puy 'zI' /L6T/ 9S8 v 'oAi w 'nsTwauox N 'qsqqsI •DoS.u1atiD•TTnEL IEL6TI'

'DSId 'IedH '

'5

sAiuv 'T

'I

SAIUY

PUTJ

''

'I'It1Y

'

ITUV

'

'qsqps 'UT) 'teq

r

SATUV

/9L611 6L "I '3> f'f '1pOO4 'roi /LL611 tL 'sAHr Kumopnaszsa '91 /ZL6T/ LL •E9 d 'OTAT) 'U9UtTA' •>I 'U1tSNDTM •w 'UOSTTM 'Ofufl .>r 'q:9J Q9 19

J1

0

'qur)I

'U1TOTPUflS

VU1Tq3Uy

/9L6T/

L8E

LE

't'9

SPO1913

SUaTZT33OZ 30 1S—UOt ATlZ

TATZ11S

6L61

'OIAD ' 'U3UrrA

')I 'WQ.tS)(Z)TM 'N 'UOSITM '21 'lObUfld 'E 'T3A10H L8 /9L6I/ 'I0 '49J1')1 'IUV 'WTqD 'V'H 'SU3SflI 'f' 'U3SSOOf) 'IUV '111143 88 /LL6I/ 'H'I '1T'')I 'V'3 '2['I '9AO.th503 ''3'I'I2UV £ /0L61/ 'Et' 'S 'II 'U'D 'UPTSTR13 '13UV 3nI £ /oL6T/ 'II 'f'U 'SUTA9n 'TUV '111343 /L6I/

'd

OV

'U

'S9 '99 'L9 '89 '69 'S'Jl 'Rtf'VI puese.td_tadd 94 4EI 1flUUV 'UrnisUi'uy 'dux son S3TehUV 'L961 :'qrtd 'OOld U1n4SUI'IUVSI 'L961 'P21 •rI 9IMOI

'LN

'cI

'0/.

'IL

'L 'EL 'IL 'SL '9/.

'LL '8L '6/.

'08 '18 'Z8 'E8 '1i8

'98 'L8 '88

'68

'06

'S'J

9 'T

'

U1flU3 'ssei J'a

'I'8961

)(IOA

"I'f 'ZtM5 'IUY I /8961/ '58 '3 'tlU3T 'D'I 'flos3dO 61 /L6IL 'S86 3 'flU3T'I 3'I 'tlDSedOd 'nUPOON 'UrnOj'Ae '111143 81 /EL6I/ 'L9I'1 'fl'M 'NTIN ')I'S 'APSATLIS 'd 'UPZH 'S 'iUfl)I '1tIOIoa121'r 'l1I43 /9L61/ '111 'N 'TUT3SN 'V 'Tt3qI 'TUV Lt7 /6961/ '6EE 'N 'TuTsN 'V '1uv Is /oL6T/ 'I€z 'ti 'TuTosN 'v 'çteqj 'Tuv Dv'wTq3 £5 /1L61/ 'zo 'w 09 /zL61/ 'sot 'N 'TUTOSPN '1uy PDv'U1Tq3 Z9 /zL61/ '6 'N 'TUTSN 'V 'TteqvI 'WT43'Tuv /EL6T/ 'E9 'N 'TUTSN 'I 'TZZOTTPd 'TPt.IV 'mTqD /L6I/ 'SLE 'N 'TflSN 'H 't9ST9t 'IPUV £ /0L61/ '191 'S'N 'U4OJ ''Fj 'ZTU4D9 'TUV /EL6T/ EE1 'r'o 'Apoo 'suioq /6961/ '9501 '12'D 'IcPOON 'S'U '8N0 ''U'f 'SU1OqJJ uy s1c 56 /oL6T/ '016 'f's 'Apoo 'I'U'f 'SWOIJ1 61 /ZL6T/ '21'M '3tO 'Q 'UUDJI '21 e.xnd ___________________ 'W3143'TddV 9E /EL6I/ 'it' 'a'S 'SS'O 'f 'UOSUt4Of'3'3 '1119t13'TUV /5L61/ '6EZ 58 /9L6iJ 'i 'f'H 'U9SI9TN 'H'21 'U9SUH 3V'U1Tq3'TUV PZ,'Wq3'IPUV 8L /5L61/ 'E9 'N 3VWII '8961 SPUZ SSTMS '3U03 UO 'euiqeO tedd U9AE 98 /9L61/ 'TZ 'N 'M 'UOUITS l4bTnI

L

V'WT43

V'T43

'teqI

'u-ços 'y 'pteq-ç' 'TPU oV'wTq3 °v 9 £LPOV

j'j'

'43

'''qP' j

UTL

E9

'UOWT5'fr_'qosat

'Uf 'N9TT{A0N 'I 'A0STt3 ' 9 'UO

'16 'Z6 UOTULtO3UI 'E6 'N StPtd 'f 'S6 'f

'T 'OTttV M

L

AtSWq3

V'Wq3'1UV U10t

UOTEO

OI3

'3 'XnttTH ''f 'UUO4 /L6T/ '89E ')[9Ut9d .0 'qA OV'Wq3'1UV ZL /L6T/ 'SLE 3v'uxq3 '9 ')PTd ')I 'q9L '21 ',t0fUfld 'W ')i29A M 'UOWTS 'TPUV ________________ '3'14

'6

pexap

—

pU

'f 'eI33flH 'f '13 'TPtH PTW1113 L2

S

/EL6I/ 'LL '[ 'toEun 'IUV DV'UXTT43 c9 /EL6I/ 'Ot'Z •96 'f ')PTd '>1 •L6 'I'V"1 'POTd 'A 'AO)[US M 'UOUITS .erI.1uv 16961/ 'S99 '86 'pOTd''V'[ 'UOWTSM wxTq3 EZ /69611 'ZL wnoi'AeT 'Wl '66 'D'I 'tiosedOd •A 'YAPS '3 ______________ /EL6TI 'tObUfld''OOT TUY 'WI3 6E /L9611 'V8Z '>1 "-I9L 'OOld oawi 'duics 'TT'd'896T a'ioT 'tOf'Ufld '21 /ZL6T/ TZS 'zoEun '-It9L e.tnd WOj\ tSSM a'EOT 'lO5Ufld /i7L6T/ •E •v•ErT7OT 'TqSetflO 'j 3VWT43'TUV_'STflbpUT Z- IEL6T/ vo'coi 'zse;t)I T" /9961/ L8LT CfY9OT 'z:;-çuqoaI •I.W 1zSx)I ')[OUq0U1Z W81t3TUV /99611 EL6 LOT V'EY 'ZUq39J •uieqD •bua SM9N euti •T /L9611 9'I 'ZUt4D9j ffZ 'UT I /L96T/ •EZ969 U1843TUV VE'6OT 'Z4UqDa /8961/ •Y•o.oTI 'z:Tu3eH /6961/ Y601 V'TTT 'Z[UT4D?i Wd1 'flesH •uIeq3'uTc /6961/ '111 'zUqD9j 'iuue ? 10L611 vrEri 'ZTUMOeU •a '-t'a •TPuV •W9D f'I' /ZL6T/ OLE S9 /EL6TI .czT7 •:a•H•tET 'taPTesuTeI •Y'(t 'z:nqDs risii '40I /iL6T/9t7 06S M'f'911 'SSOj 9ST3tT3S 1L96T/ 9LE1 /•pa •cl LS UOUTT4SM 6961 'SsoU '•;t sir qndoeds ••j/ •f•811 '3TZfl .)I 'pTpI P4DVWT4DTUV /1L61/ •i: f611 'OTZnH 'uesu j' tq -r /EL6T/ .ssT f ')[9Ui49d 1? /EL6T/ •SZ o--t 'qci 2 'NeUt9d 19L611 •8S1 azzi 'PTWWS •I 'tof,und uie LL /1L61/ L6E dIEZT 'tTOIDS 'M 'UOUITS PTWPID /OL6T/ ZLE •V'•7ZT 'z:rEtups •Y'D_'U9St9d 'NSW d'H ')[Otl 9TeDU9TOS /8961/ L9Z 69 /9L61/ 6EE 1SZ1 ')iI9)[9S '19UTO8 f

't9J

'6T

OT

I

'ZTU38

V8OT

'3UITAOT3

'PTWS

'

T

pu uieqydd

't9

iw

pu

T

'nuey

•E

S

Z 'U ITUV T

.eni.iuvT

6S

'E 'TnqTT 4D'TV

stn

MfLTT

? 3VWq3IPUY

ooi 'qA

UTL Ab

fV

'f

1

1T9AT0

1980

126. 127. 128. 129. 130. 131. 132. 133. 134. 135. 136. 137. 138. 139. 140. 141. 142. 143.


M. Semler, H. Adametzová, J. Electroanal.Chem. 56 /1974/ 155. M. Sharp, Anal.Chim.Acta62 /1972/ 385. M. Sharp, Anal.Chim.Acta 61 /1972/ 99. M. Sharp, Anal.Chim.Acta 59 /1972/ 137. M. Sharp, Anal.Chirn.Acta 65 /1973/ 405. W. Simon, W.E.Morf, P.Ch. Meier, Structure and Bonding 16 /1973/ 114. K. Srinivasan, G.A. Rechnitz, Anal.Chem. 41 /1969/ 1203. M. Sugawara, T. Nakajima, T. Kambara, J. Electroanal.Chem. 67 /1976/ 315. W. Szczepaniak, K. Ren, Anal. Chim.Acta 82 /1976/ 37. K. Tôth, E. Pungor, Proc. IMECO Symp. 1968. p. 35. K. Tóth, E. Pungor, Anal. Chim.Acta 51 /1970/ 221. P.K.C. Tseng, W.F. Gutknecht, Anal.Lett. 9 /1976/ 795. P.K.C. Tseng, W.F. Gutknecht, Anal. Chem. 48 /1976/ 1996. J. Vesely, Coll. Czech. Chem. Commun. 36 /1971/ 3364. J. Vesely, 0.J. Jensen, B. Nicolaisen, Anal. Chim.Acta 62 /1972/ 1. J.L. Walker, Jr., Anal.Chem. 43 /1971/ 89A. D. Weiss, Chem. Listy 65 /1971/ 1091. A.C. Wilson, K.H. Pool, Talanta 23 /1976/ 387.