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Colorimetric determination of periodate with benzhydrazide
SHORT
COMMUNICATIONS
Calorimetric
199
determination
of periodate
with
benzhydrazide
TIw determination of pcriodnte Itas gained considerable significance during tllc last few years. Grnvimctric mctllocls baSec1 on precipitation with tetrapllci7ylarsoi~iuln or tetrapl~enylp~los~,l~oniunl cllloride arc availablc~, and inlrarccl~ and ultraviolctx spectropllotoiiietry llavc also lxeii used quantifativcly. A pl~otometric method for its determination in tllc presence of otllcr osidizing agents has been dcscribccl*l. -4 colorimetric mctllod after cstraction wit11 crystal violet in lxnxcnc! 11:~salso been devised”. Rcnzoylhydrazine or bcnzl~ytlrazicle lens been used” in titrating perioclatc in vcr_v dilute sulfuric acicl media. In the present colnnlunicatic,n tile USC of IxxWllydr;~ziclc as a colorinictric reagent for tlie clctcrminntion of periodate is dcscrilxcl. z\‘eagout.s
(fi~ahiuckrodt ~.~/Iomica~ bl~‘or/~s). i\ 0.01 .qf solutioll in 0.12.5 acid was prepared. Bfmzliyri~azidc. Tliis was prcparcd front ctllyl benzoate and liyclrazine li~*tlratc. An aqueous 0.1 n/I stock solution of tlic rcagcnt was prepared, ancl more dilute solutions were preparccl by dilution. All otllcr reagents used in tllis study were of analytical grade. ~otassitl9~l. ficriodatc
iV1
sulfuric
meter
Bccknian SI’ectroI’llotonlcter 1Modcl7 ; 13ausc11 and Lomb
iIeterrui~~ation
of absorfition
Moclcl Spcctronic
rm;
zind x-cm
silica
Coleman
pl-r
sjcctrum
Figure I sl~ows tile absorpjion spectrum for a solution potassium pcriodatc in 95 o/oethanol obtained against a reagent
Effect
cells;
20.
containing
2.0
- x0-3
hr/
blank.
of $H and time on nbsovbn~m
different PH values on the absorbance nwasurenients, several solutions containing 5.0 ml of 0.01 M potaSSiUn1 periodate, 2.0 ml of 0.10 M potassium llydrogen plltllalate ancl 10.0 ml of 0.01 Ikf benzhydrazicle WCTC placed in separate flasks. The PH values of tile solutions were varied between e.5 and 3.1 wit11 3 M sulfuric acid and I n/rpotassium hydroside ; the solutions were not diluted further. Tile plot of absorbance versus 1)~ measured against a reagent blank is sllown in Fig. 3. To study tile effect of time, solutions were preparccl as above with a pH of 1.0. The change in absorbance was noted at I-min intervals for 40 min. A simila-i solution after dilution to 50.0 ml wit11 95cyo etllanol was also observed. \Yl~en etllanol was absent, tile absorbance decreasecl quite rapidly \vitll time over 40 min; in the presence of ethanol, tile initial absorbance reading was less, but after IO min, tile decrease in absorbance with time was only gradual. For convenience, a tirnc of 1.2 min was selected. To
Prepavatio7t
determine
tllc effect
of calibration
of
cwvc
Different volumes of 0.01 M potassium periodate were pipetted into 50.0-1111 volumetric flasks. Then 2 ml of 0.1 M potassium Ilydrogen plltlialate and 10.0 ml of
SHORT
COMM UNICA’l’IONS
ul
60.
0.6 -
0.4.
0.2 -
400
0
Fig. I. of 0.10 Fig.
2.
TA’RLE EFFECT Ions
450
550
500
Alworption slxxtrum h4 ICI-IC~I-IJO.I. 10.0
A, nm
0
6’
of pcriotlntc-l,cnzlIytIrazitlc bcnzhydraziclc,
ml of 0.01 M
Effect of l>Elon absorbance.
3
pH
10.0 ml of 0.01 AI K104, IiIixturc. 95% ethanol for dilution to 50.0 ml.
2.0
1
2
d ml
(A) After 12 miri; (U) after 15 niin.
1 01’ DIVIZRSE
6
IONS
ON TIIE
Dl~TERhfINATION
Tolerw?rct!" (tr~olc viblioQ)
lO7l.S
14.3 2.57 >I.{.3 > l-t.3 2.86 0.13 0.014 0.014 14.3 8.57 5.7 2.86
CPC %n z+ TvIn3.k 1\13+ Cd Q-1. C”‘+ Sn3-b Sn .1+ CA”’ Mg”+ I-Q?+ I-&“+
OF PERYOI3ATI5 Toleramch (rnolc ratioc)
~.~-_
IOnBrOnClO:,CaI-1303CO$Fc(CN) ,,a’Fc(CN),,:‘CrOJnNOaSCNClClIBrClO.,p
l-‘b?i.
0.21
A&z+ BP+
> ‘4.3 2.85 > 71.0
c3043lMooj”-
0.03 > 14.3 14.3
SOa”Sod*s3032-
SO.12-
5.7 5.7 5.7 2.86 8.57 I.43 CI I *43 ;.,: 0.014 0.0x4 CI CI 5.7 2.8G X4.3
CIl’ CI
As033AsOr~-
23.0
Pop-
x4.3
n Anions were adclccl as their soclium, potassium or ammaniuni salt, and cations as their chloride or nitrate salt. b Error of 2% tolcmted. 0 Mole ratio of salt added to T
An&.
Clrina. Acta,
45 (19691
Igg--201
SHORT
201
COMMUNICATIONS
0.01 M benzhyclrazicle were acldccl and the mixture was diluted to the mark with 95”/0 ethanol. The absorbances of the solutions were read at 450 nm in ~-cm silica cells exactly 1’2 min after the addition of benzhydrazicle. A linear calibration was found over the range 6.0-x4.0* 110-d ICI periodate in the final solution; zero absorbance was found fo;_ 5. IO -4 M periodate.
The effect of interfering ions on the determination of periodatc was investigatetl. The mixtures containecl r3.S mg of potassiutn perioclatc and varying amounts of salts in excess of the periodate, ancl were treated by the above method. The results are given in Table I.
Tile addition of potassium hydrogen plltllalate to tile periodate-l,cnzllyclrazitle mixture helpecl to stabilize the color. The best 1)~ for color stability was between 1.0 was the color clisappearcd. Complete color clevelopiiient and 1.5; above pH 3.10 obtained within a few minutes after the aclclition of bcnzhyclraziclc at room temperature. The absorbance read at 450 nm, the wavelength of maximum absorption, clecrcasecl rapidly bcforc dilution with 95% ethanol ; the rate of decrease was slower after dilution. We wish to thank Dr. CH..\I
.q. M. ~SCARR1LI.A 1’. I;. MALONE\P. M. MALOSEY
I/lieu College of Syrcmm IJnivcrsity, IJticcc, N. Y. 23502 (I/S.-A .)
I<. I
jt/etlmris
of bcnzliytlrazide.
of Qtrotalitcttivc
/wr*gcbttic
Analysis,
lt~tcrscicncc
I’ublishcrs,
New
York,
1963. %I.
C. E.
AL-KAYSSl
AND
~ROUTHAnlEL.
SCIXULEK,
Scc~.Clhtt., C.
I-IuDRIcI;
J.
VULTERIN
(Received
12.
iUAGEl%,
1-1. ;\IERIi,
P.
ENDR~I
2 (1960) AND AND
B.
1.). h.vn
.-Imtcl. ~IAKTIN, I,.
C/rim. ACflL, 28 (rgG3) 1971. -Ilm.Chmu. JK. AND c. BANKS../.
TIARAS.
Uttiv.
Awa.
117; C..4.. 61 (196.1) rzgf). BERGIZH. _4ad. C/rem., 38 (1966)
J.
September
%YKA,
Ta/nwln,
5tl1, I9GS)
I0
(IgO.3)
Sg
I.
Sci. 791.
i3rtrlrcfwsl.
Sac., 71 (1949)
I~olutrrfo
Eolvos
3071.
.\:orrr>ttofcte,
COMMUNICATIONS
Calorimetric
199
determination
of periodate
with
benzhydrazide
TIw determination of pcriodnte Itas gained considerable significance during tllc last few years. Grnvimctric mctllocls baSec1 on precipitation with tetrapllci7ylarsoi~iuln or tetrapl~enylp~los~,l~oniunl cllloride arc availablc~, and inlrarccl~ and ultraviolctx spectropllotoiiietry llavc also lxeii used quantifativcly. A pl~otometric method for its determination in tllc presence of otllcr osidizing agents has been dcscribccl*l. -4 colorimetric mctllod after cstraction wit11 crystal violet in lxnxcnc! 11:~salso been devised”. Rcnzoylhydrazine or bcnzl~ytlrazicle lens been used” in titrating perioclatc in vcr_v dilute sulfuric acicl media. In the present colnnlunicatic,n tile USC of IxxWllydr;~ziclc as a colorinictric reagent for tlie clctcrminntion of periodate is dcscrilxcl. z\‘eagout.s
(fi~ahiuckrodt ~.~/Iomica~ bl~‘or/~s). i\ 0.01 .qf solutioll in 0.12.5 acid was prepared. Bfmzliyri~azidc. Tliis was prcparcd front ctllyl benzoate and liyclrazine li~*tlratc. An aqueous 0.1 n/I stock solution of tlic rcagcnt was prepared, ancl more dilute solutions were preparccl by dilution. All otllcr reagents used in tllis study were of analytical grade. ~otassitl9~l. ficriodatc
iV1
sulfuric
meter
Bccknian SI’ectroI’llotonlcter 1Modcl7 ; 13ausc11 and Lomb
iIeterrui~~ation
of absorfition
Moclcl Spcctronic
rm;
zind x-cm
silica
Coleman
pl-r
sjcctrum
Figure I sl~ows tile absorpjion spectrum for a solution potassium pcriodatc in 95 o/oethanol obtained against a reagent
Effect
cells;
20.
containing
2.0
- x0-3
hr/
blank.
of $H and time on nbsovbn~m
different PH values on the absorbance nwasurenients, several solutions containing 5.0 ml of 0.01 M potaSSiUn1 periodate, 2.0 ml of 0.10 M potassium llydrogen plltllalate ancl 10.0 ml of 0.01 Ikf benzhydrazicle WCTC placed in separate flasks. The PH values of tile solutions were varied between e.5 and 3.1 wit11 3 M sulfuric acid and I n/rpotassium hydroside ; the solutions were not diluted further. Tile plot of absorbance versus 1)~ measured against a reagent blank is sllown in Fig. 3. To study tile effect of time, solutions were preparccl as above with a pH of 1.0. The change in absorbance was noted at I-min intervals for 40 min. A simila-i solution after dilution to 50.0 ml wit11 95cyo etllanol was also observed. \Yl~en etllanol was absent, tile absorbance decreasecl quite rapidly \vitll time over 40 min; in the presence of ethanol, tile initial absorbance reading was less, but after IO min, tile decrease in absorbance with time was only gradual. For convenience, a tirnc of 1.2 min was selected. To
Prepavatio7t
determine
tllc effect
of calibration
of
cwvc
Different volumes of 0.01 M potassium periodate were pipetted into 50.0-1111 volumetric flasks. Then 2 ml of 0.1 M potassium Ilydrogen plltlialate and 10.0 ml of
SHORT
COMM UNICA’l’IONS
ul
60.
0.6 -
0.4.
0.2 -
400
0
Fig. I. of 0.10 Fig.
2.
TA’RLE EFFECT Ions
450
550
500
Alworption slxxtrum h4 ICI-IC~I-IJO.I. 10.0
A, nm
0
6’
of pcriotlntc-l,cnzlIytIrazitlc bcnzhydraziclc,
ml of 0.01 M
Effect of l>Elon absorbance.
3
pH
10.0 ml of 0.01 AI K104, IiIixturc. 95% ethanol for dilution to 50.0 ml.
2.0
1
2
d ml
(A) After 12 miri; (U) after 15 niin.
1 01’ DIVIZRSE
6
IONS
ON TIIE
Dl~TERhfINATION
Tolerw?rct!" (tr~olc viblioQ)
lO7l.S
14.3 2.57 >I.{.3 > l-t.3 2.86 0.13 0.014 0.014 14.3 8.57 5.7 2.86
CPC %n z+ TvIn3.k 1\13+ Cd Q-1. C”‘+ Sn3-b Sn .1+ CA”’ Mg”+ I-Q?+ I-&“+
OF PERYOI3ATI5 Toleramch (rnolc ratioc)
~.~-_
IOnBrOnClO:,CaI-1303CO$Fc(CN) ,,a’Fc(CN),,:‘CrOJnNOaSCNClClIBrClO.,p
l-‘b?i.
0.21
A&z+ BP+
> ‘4.3 2.85 > 71.0
c3043lMooj”-
0.03 > 14.3 14.3
SOa”Sod*s3032-
SO.12-
5.7 5.7 5.7 2.86 8.57 I.43 CI I *43 ;.,: 0.014 0.0x4 CI CI 5.7 2.8G X4.3
CIl’ CI
As033AsOr~-
23.0
Pop-
x4.3
n Anions were adclccl as their soclium, potassium or ammaniuni salt, and cations as their chloride or nitrate salt. b Error of 2% tolcmted. 0 Mole ratio of salt added to T
An&.
Clrina. Acta,
45 (19691
Igg--201
SHORT
201
COMMUNICATIONS
0.01 M benzhyclrazicle were acldccl and the mixture was diluted to the mark with 95”/0 ethanol. The absorbances of the solutions were read at 450 nm in ~-cm silica cells exactly 1’2 min after the addition of benzhydrazicle. A linear calibration was found over the range 6.0-x4.0* 110-d ICI periodate in the final solution; zero absorbance was found fo;_ 5. IO -4 M periodate.
The effect of interfering ions on the determination of periodatc was investigatetl. The mixtures containecl r3.S mg of potassiutn perioclatc and varying amounts of salts in excess of the periodate, ancl were treated by the above method. The results are given in Table I.
Tile addition of potassium hydrogen plltllalate to tile periodate-l,cnzllyclrazitle mixture helpecl to stabilize the color. The best 1)~ for color stability was between 1.0 was the color clisappearcd. Complete color clevelopiiient and 1.5; above pH 3.10 obtained within a few minutes after the aclclition of bcnzhyclraziclc at room temperature. The absorbance read at 450 nm, the wavelength of maximum absorption, clecrcasecl rapidly bcforc dilution with 95% ethanol ; the rate of decrease was slower after dilution. We wish to thank Dr. CH..\I
.q. M. ~SCARR1LI.A 1’. I;. MALONE\P. M. MALOSEY
I/lieu College of Syrcmm IJnivcrsity, IJticcc, N. Y. 23502 (I/S.-A .)
I<. I
jt/etlmris
of bcnzliytlrazide.
of Qtrotalitcttivc
/wr*gcbttic
Analysis,
lt~tcrscicncc
I’ublishcrs,
New
York,
1963. %I.
C. E.
AL-KAYSSl
AND
~ROUTHAnlEL.
SCIXULEK,
Scc~.Clhtt., C.
I-IuDRIcI;
J.
VULTERIN
(Received
12.
iUAGEl%,
1-1. ;\IERIi,
P.
ENDR~I
2 (1960) AND AND
B.
1.). h.vn
.-Imtcl. ~IAKTIN, I,.
C/rim. ACflL, 28 (rgG3) 1971. -Ilm.Chmu. JK. AND c. BANKS../.
TIARAS.
Uttiv.
Awa.
117; C..4.. 61 (196.1) rzgf). BERGIZH. _4ad. C/rem., 38 (1966)
J.
September
%YKA,
Ta/nwln,
5tl1, I9GS)
I0
(IgO.3)
Sg
I.
Sci. 791.
i3rtrlrcfwsl.
Sac., 71 (1949)
I~olutrrfo
Eolvos
3071.
.\:orrr>ttofcte,