機能水研究

ORIGINAL

Vol.6(1), p. 27-33, 2011

Determination and Speciation of Vanadium(IV) and Vanadium(V) in Water
Sample by Ion Chromatography in Combination with Electron Spin ResonanceAnalysis and/or Electrolysis-Induced Reduction of Vanadium(V)Takayuki Mokudai,1 Mitsuo Ikeda,2 Masahiro Kohno,1 and Yoshimi Niwano1*
1
2

New Industry Creation Hatchery Center, Tohoku University

Research & Development Headquarters, Asahiberweries, Ltd.
2010.10.26

Received

2 0 11 . 4 . 1

Accepted

Summary
Attention has been paid to vanadium because of its antidiabetic action. There are a lot of natural waterproducts whose sales point is to contain vanadium. However, in most cases, existing form of vanadium is
not clear. There have been two methods developed for the differential determination of vanadium. One isgraphite-furnace atomic absorption spectrometry based on the extraction of vanadium(V) andvanadium(IV) with different solvents. The other is the speciation method by using high performance liquid
chromatography and inductively coupled plasma mass spectrometry. The present study demonstrated that
an ion chromatography is very effective for the separation of vanadium(IV) and vanadium(V). If
vanadium(V) is existed in aqueous samples, it can be reduced by electrolysis, resulting in the appearanceof vanadium(IV). In addition, since electron spin resonance (ESR) spectrometry can be used to confirm theexistence of vanadium(IV) based on the spectrum with eight signals, ESR spectrometry can detect theelectrolysis-induced reduction of vanadium(V) to vanadium(IV). Therefore, we propose that the
combination of these three methods is very useful for the determination and speciation of vanadium inwater samples.
Key Words: vanadium, reduction, ion chromatography, electron spin resonanceelement for human body4), because it participates inIntroduction
Vanadium is a group 5 transition metal, andglucose and lipid metabolic pathways. There haveunder standard physiological conditions (pH 3-7,

been many studies on the insulin-like and anti-diabetic

aerobic

effects

atmosphere,

temperature),

thethermodynamicallyaqueousambient

ofvanadium5-8),

and

some

vanadiumstateswhich

arecompounds have been reported to be effective inkineticallypossiblearelowering

oxidationandsolution,blood

glucoselevel9-13).

Furthermore,1,

peroxovanadium(V) has attracted pharmacologists’. In some marine life forms such as ascidians,

attention in terms of its insulin mimetic functions14, 15).

vanadium(III)It was also reported that vanadium(V) exerts

trivalent (III), tetravalent (IV), and quinquevalent (V)2)

isconcentrated

in

specialized3)

vanadocytes .

insulin-mimetic activities in a synergistic manner withperoxide16), and peroxovanadium(V) complexes such

Vanadium is suggested to be an essential trace

Yoshimi Niwano: Tohoku University Graduate School of Dentistry; 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
Tel: +81-22-721-7075

Fax: +81-22-342-1682

27

E-mail：niwano@m.tohoku.ac.jp

Determination of vanadium in water samples
as K2[VO(O2)2(C5H4NCOO)]・2H2O are also effective

contain V2O5 (20 ng/ml) and VOSO4 (20 ng/ml). The

insulin mimics17-19). In addition to peroxovanadium(V)standard solution, ultrapure water, and natural watercomplexes, vanadium(IV) salts such as VOSO4 were

were subjected to ion chromatography analysis. As

clinically examined to ascertain their effectiveness onneeded, the natural water and V2O5 solution werediabetes in humans

20, 21). However, bioavailability ofthese inorganic salts is generally very low.

electrolyzed with the variable diaphragm electrolyzer

It wasat applied voltage of 12 or 15 V for 15 min. To

also reported that vanadyl(IV) compounds are lessdetermine vanadium, a direct concentration method

toxic in terms of LD50 values in rats than

was used in the ion chromatographic analysis with thevanadium(V)

22,

23)

, and vanadium exists in the

Dionex DX-500 high pressure liquid chromatography

vanadyl(IV) state in the vanadium(V) salt-treatedsystem24)(DionexCorp.,

Sunnyvale,CA).

rats . Indeed, more recently, it was reported that

Chromatographic separation was performed on IonPac

oxovanadium(IV) complexes are effective as a potent

CS5A

25)

antidiabetic agent .

(DionexCorp.)

as

a

guard

column,IonPacTCC-2 (Dionex Corp.) as a concentration

In Japan, based on the beneficial aspects ofcolumn, and IonPac CG5A (Dionex Corp.) as a

vanadium as described above, a lot of natural water

separation column at the flow rate of 1.0 ml/min at

products whose sales point is to contain vanadium

30-35℃. As for elution, a mixture containing 0.5 M

have been launched on the market. However, only a

oxalic acid, 75 mM sodium sulfate and 95 mM lithium

few studies have been conducted to analyze vanadiumhydroxide was used.

in natural water

26, 27), and in most cases the existent

The natural water, V2O5 solution, and VOSO4

form or state of vanadium is not clear. In the present

solutionstudy,

we

proposeausefulmethodfor

wereelectrolyzed

with

the

variablethediaphragm electrolyzer at applied voltage of 12 or 15

determination and speciation of vanadium(IV) and

V for 5 to15 min. Then, each test sample in a sample

vanadium(V) in water sample.

tube (φ4 mm x 30 cm) was placed at 77 K in the ESR
spectrometer (JES-FA-100, JEOL, Tokyo, Japan). ESR

Materials and Methods

analysis was performed under the conditions as

Reagents, test materials, and electrolyzer

follows:

field

sweep,

322.861±100

mT;

field

Reagents were purchased from the following

modulation frequency, 100 kHz; filed modulation

sources: Vanadium oxide (V2O5), and vanadyl sulfate

width, 2 mT; amplitude, 100; sweep time, 4 min; time

(VOSO4) from Wako Pure Chemicals (Osaka, Japan).

constant, 0.1 s; microwave frequency, 9.054 GHz;

All other reagents used were of analytical grade. Test

microwave power, 8 mW.

water materials used were commercially available
natural water whose sales point was to contain
vanadium (henceforth described as natural water

Results and Discussion
Representative chromatogram of V2O5 andthroughout the paper), and ultrapure water. As an

VOSO4 analyzed by ion chromatograph is shown inelectrolyzer, a diaphragm type electrolyzer in which

Fig. 1, indicating that the peaks at 5-6 min and at

the electrode material is platinum coated titanium

16-17

plate and the interelectrode distance is 8 mm (Super

vanadium(V), respectively.

Water Mini, Artec Co., Ltd., Tokyo, Japan) was

chromatograms of the natural water and the ultrapure

upgraded to have an ability of varying freely electricwater. No clear peaks were observed in thecurrent and applied voltage, and used in the present

chromatogram of the ultrapure water, whilst a large

study (henceforth described as variable diaphragmpeak with a shoulder was observed at 14-17 min ofelectrolyzer throughout the paper).

retention time in the chromatogram of the natural

min corresponded

to vanadium(IV)andFigure 2 shows thewater. Since it was thought that the large peak wasderived from vanadium(V), the natural water was thenIon chromatography and ESR analyses for vanadiumelectrolyzed at applied voltage of 12 V for 15 min.

Standard aqueous solution was prepared to28

Ultrapure water

Before electrolysis

Fig. 1 Representative ion chromatogram of V2O5
and VOSO4 aqueous solution.

Natural water before electrolysis

The peaks at 5-6 min and at 16-17 min corresponded to
vanadium(IV) and vanadium(V), respectively. The
peak corresponds to vanadium(IV) is presumably
derived from VO2+, and that corresponds tovanadium(V) presumably from VO2+.

Figure 2 at the bottom shows the chromatogram of thesample taken from the cathode. Since retention time ofthe peak corresponded to that of VOSO4, it was likely
derived from vanadium(IV), a reduced form of
vanadium(V). Electrolysis is a method applying thepassage of an electric current through an ionic

Natural water

substance solution, which results in chemical reactions

after electrolysis

at the electrodes. Thus, we assumed that the method
could be applied to reduce vanadium(V). To further
confirm this, 0.05 mM (9.1 μg/ml) V2O5 aqueous
solution was electrolyzed at applied voltage of 12 V
for 15 min. Figure 3 shows the chromatogram of 0.05
mM V2O5 solution before and after electrolysis. A
half-broad peak derived from V2O5 was observed
before electrolysis. After electrolysis a peak at around
5 min of retention time appeared, suggesting that

Fig. 2 Representative ion chromatograms of

vanadium(V) was partially reduced to vanadium(IV).

ultrapure water and natural water before andIn this paper, we showed the data obtained by using

after electrolysis.
No clear peaks were observed in the chromatogram of
the ultrapure water, whilst a large peak with a shoulder
was observed at 14-17 min of retention time in thechromatogram of the natural water before electrolysis.
After electrolysis at applied voltage of 12 V for 15 min,a clear peak at around 6 min appeared.

the variable diaphragm electrolyzer at applied voltageof 12 V for 15 min. We firstly tried to electrolyze
samplesolutionsbyapplyingacommerciallyavailable diaphragm type electrolyzer (Super Water
Mini). However, clear reduction of vanadium(V) wasnotobserved.

Thus,

we

changedelectrolysis

conditions and found that applied voltage of 12 V for

ESR spectroscopy is a technique for studying

15 min could reduce vanadium(V) to vanadium(IV).

chemicals which possess one or more unpaired29

Before electrolysis

Fig. 3After electrolysis

Representative ion chromatograms of 0.05 mM V2O5 solution before
and after electrolysis at applied voltage of 12 V for 15 min.
After electrolysis, a peak at around 5 min appeared.

electrons, so called free radicals, and inorganic

consists of eight signals because of the equation

complexes which possess a transition metal ion.

2nI+1=828). Thus, each ESR spectrum in Fig. 4 was

Therefore, ESR analysis of the electrolyzed natural

most likely derived from vanadium(IV). In addition,water was conducted. However, no clear spectra were

we calculated the ESR parameters based on theobserved, possibly because of the low sensitivity ofanisotropy of spectra, which is a characteristic feature

ESR to detect the vanadium. Indeed, according to theof vanadium(IV) complex 24, 29), as shown in Figs. 4

ion chromatography analysis, the concentration ofand 5. That is, g⊥=1.99, g∥=2.08, g0 =2.02, A⊥

vanadium(IV) in the electrolyzed natural water was=92.0 x 10-4 cm-1, A∥=190.3 x 10-4 cm-1, A0=123.6 xseveral dozen ppb (ng/ml). As a next step, 10 μg/ml of

10-4 cm-1 for VOSO4 solution as shown in Fig. 5, and g

V2O5 aqueous solutions electrolyzed at applied voltage⊥=1.99, g∥=2.00, g0 =1.99, A⊥=84.6 x 10-4 cm-1, A

12 or 15 V for 5 to 10 min were
subjected to the ESR analysis.
Representative ESR spectra areshown in Fig. 4. When V2O5
aqueoussolution

waselectrolyzed at 12 V, the signal
intensity

increased

withelectrolysis time. Also the higher
the applied voltage was, thehigher the signal intensity was.
To confirm if the signal wasderivedfromvanadium(IV),aqueous solution of VOSO4 (1μg/ml) was subjected to the ESR
analysis. A representative ESR
spectrum derived from VOSO4 isshown in Fig. 5. Since thenuclear spin of vanadium(IV) is
I=7/2, the spectrum of vanadiumFig. 4

Representative ESR spectra of V2O5 aqueous solution electrolyzed
at applied voltage 12 or 15 V for 5 to 10 min.

The signal intensity increased dependently on electrolysis time and applied voltage.

30

List of Abbreviations
tetravalent vanadium;

After electrolysis

vanadium(IV)quinquevalent vanadium;vanadium(V)electron spin resonance; ESR

References
1) Butler

A,

CarranoCJ:

Coordination

chemistryof

vanadiuminbiologicalsystems. Coord. Chem. Rev.,
Fig. 5109, 61-105, 1991.

Representative ESR spectrum of VOSO4.

2) Chasteen

Eight signals were observed as the spectrum of vanadium(IV).

∥ =184.9 x 10

-4-1

cm , A0=118.0 x 10

-4

cm

-1

for

ND,

Grady

Characterization

of

the

stabilityof

Hollowaybinding,

kinetics,

and

redox

JK,
CE:

electrolyzed V2O5 solution as shown in Fig. 4. Since

vanadium(IV) and vanadium(V) protein complexes

the values of these parameters obtained from thein serum. Inorg. Chem., 25, 2754-2760, 1986.

spectra in Figs. 4 and 5 are very close to each other,

3) Nette

G,

ScippaS,

Genovese

M,

et

al.:

each spectrum in Fig. 4 was surely derived from

Cytochemical localization of vanadium(III) in

vanadium(IV).

blood cells of ascidian Phallusia mammillata

For analysis of vanadium in water samples by

Cuvier, and its relevance to hematic cell lineage

graphite-furnace atomic absorption spectrometry, it

determination.

Comp.

Biochem.

Physiol.

C.

was reported that separation and preconcentration

Pharmacol. Toxicol. Endocrinol., 122, 231-237,

method

1999.

based

on

the

solvent

extractionofvanadium(V) with 1-butanol and vanadium(IV) with
8-mercaptquinolineiseffectivefor4) Thompson KH: Vanadium and diabetes. Biofactors,

differential

10, 43-51, 1999.

30)

determination of vanadium(V) and vanadium(IV) .

5) Bell RHJ, Hye RJ: Animal models of diabetes

More recently, it was reported that a simple andmellitus: Physiology and pathology. J. Surg. Res.,sensitive method for the speciation of vanadium(III),35, 433-460, 1983.

(IV), and (V) was developed by using high6) Heyliger CE, Tahiliani AG, McNeill JH: Effect ofperformance liquid chromatography and inductively

vanadate on elevated blood glucose and depressed31)

cardiac performance of diabetic rats. Science, 227,

coupled plasma mass spectrometry (HPLC-ICPMS) .
The

present

study

demonstrated

that

the

ion

1474-1477, 1985.

chromatography coupled with ESR analysis could be a7) Byrne AR, Kosta L: Vanadium in foods and intool effective for detection and speciation of vanadium

human body fluids and tissues. Sci. Total Environ.,in solutions. Even if the concentration of vanadium is10, 17-30, 1978.

too low to detect by ESR spectroscopy, electrolysis8) Stroop SD, Helinek G, Greene HL: More sensitive

under the certain conditions could reduce theflameless atomic absorption analysis of vanadium

vanadium(V)in tissue and serum. Clin. Chem., 28, 79-82, 1982.

tovanadium(IV),supportingtheevidence for the existence of vanadium.

9) Ramanadham S, Mongold JJ, Brownsey RW, et al.:Oral vanadyl sulfate in treatment of diabetes
mellitus in rats. Am. J. Physiol., 257, H904-H911,

31

activities of peroxovanadium(V) complexes with a

1989.
10) Pederson RA, Ramanadham S, Buchan AM, et al.:heteroligand. J. Inorg. Biochem., 86, 649-56, 2001.

on20) Cusi K, Cukier S, DeFronzo RA, et al.: Vanadyl

streptozotocin induced diabetes in rats. Diabetes,

sulfate improves hepatic and muscle insulin

38, 1390-1395, 1989.

sensitivity in type 2 diabetes. J. Clin. Endocrinol.

Long-term

effectsofvanadyltreatment11) Brichard SM, Okitolonda W, Henquin JC: Long

Metab., 86, 1410-7, 2001.

term improvement of glucose homeostasis by21) Goldfine AB, Simonson DC, Folli F, et al.: In vivo

vanadate treatment in diabetic rats. Endocrinology,

and in vitro studies of vanadate in human and123, 2048-2053, 1988.

rodent diabetes mellitus. Mol. Cell. Biochem., 153,
217-231, 1995.

12) Sakurai H, Tsuchiya K, Nukatsuka M, et al.:22) Waters MD: Toxicology of vanadium. Adv. Med.

Insulin-like effect of vanadyl ion on streptozotocin

Toxicol., 2, 147-189, 1977.

induced diabetic rats. J. Endocrinol., 126, 451-459,

23) Gomez M, Domingo JL, Llobet JM, et al.:

1990.
JH:

Evaluation of the efficacy of various chelating

Mechanisms of vanadium action: Insulin-mimetic

agents on urinary excretion and tissue distribution

or insulin-enhancing agent? Can. J. Physiol.

of vanadium in rats. Toxicol. Lett., 57, 227-234,

Pharmacol., 78, 829-847, 2000.

1991.

13) CamMC,

Brownsey

RW,

McNeill24) Sakurai H, Shimomura S, Fukuzawa K, et al.:

14) Rehder D, Costa Pessoa J, Geraldes CF, et al.: In
vitro study of the insulin-mimetic behaviour of

Detectionofoxovanadium

(IV)

and

vanadium(IV, V) coordination compounds. J. Biol.

characterization of its ligand environment in

Inorg. Chem., 7, 384-96, 2002.

subcellular fractions of the liver of rats treated withpentavalent vanadium(V). Biochem. Biophys. Res.

15) Thompson KH, McNeill JH, Orvig C: Vanadium

Commun., 96, 293-298, 1980.

compounds as insulin mimics. Chem. Rev., 99,

25) Adachi

2561-2572, 1999.

Y,

YoshidaJ,

KoderaBis(allixinato)oxovanadium(IV)16) Kadota S, Fantus IG, Deragon G, et al.:complexal.:ispotentstructure-activity relationship for a series ofadipocytes. Effects of vanadate and H2O2. J. Biol.

hydroxypyrone-vanadium

Chem., 262, 8252-8256, 1987.

Chem., 49, 3251-3256, 2006.
preparationofcomplexes.

J.

on
Med.

26) Miura J: Determination of trace amounts of17) Shaver A, Ng JB, Hall DA, et al.: Insulin mimetic
complexes:

studiesabinding and insulin receptor kinase activity in rat

structureagent:

etStimulation of insulin-like growth factor II receptor

peroxovanadium

antidiabeticY,

vanadium in natural waters and coal fly ash with

and2-(8-quinolylazo)-5-(dimethylamino)phenol

potassiumoxodiperoxo(pyridine-2-carboxylato)vanadate(V),reversed-phase

K2[VO(O2)2(C5H4NCOO)].2H2O, and potassium

spectrophotometry. Anal. Chem., 62, 1424-1428,

oxodiperoxo(3-hydroxypyridine-2-carboxylato)van

1990.

adate(V), K2[VO(O2)2(OHC5H3NCOO)].3H2O, andliquidbychromatography-27) Fan Z, Hu B, Jiang Z: Speciation analysis of

their reactions with cysteine. Inorg. Chem., 32,

vanadium

3109-3113, 1993.

electrothermal vaporization inductively coupled

18) PosnerBI,

Faure R,

Burgess JW, et al.:plasmain
opticalnaturalemission

Peroxovanadium compounds. A new class of

separation/preconcentration

potent phosphotyrosine phosphatasethenoyltrifluoroacetone

inhibitors

water

samples

spectrometry

by
after
with

immobilizedonwhich are insulin mimetics. J. Biol. Chem., 269,

microcrystalline naphthalene. Spectrochimica Acta

4596-4604, 1994.

Part B: Atomic Spectroscopy, 60, 65-71, 2005.

19) Kanamori K, Nishida K, Miyata N, Okamoto K, et28) Zeng B, Shen T, Wu A, et al.: Spectroscopic andal.: Syntheses, structures, stability, and insulin-like

DFT study on the interaction system of vanadium32with L-proline in aqueous solution. J Phys Chem A,

in water samples by graphite-furnace AAS after

114, 5211-5216, 2010.

solvent

characterization of V
12-molybdophosphate.

as a counter-ion of the
Influence

of

with

1-butanoland8-mercaptquinoline. Bunseki Kagaku (in Japanese),

29) Bayer R, Marchal C, Liu FX, et al.: ESR
4+extraction

50, 133-138, 2001.

thermal31) Li XS, Glasauer S, Le XC: Speciation of vanadium

treatments. J. Mol. Catal. A Chem., 110, 65-76,

in oilsand coke and bacterial culture by high1996.

performance liquid chromatography inductively30) Shimizu T, Motegi T, Nakano M, et al.: Fractional

coupled plasma mass spectrometry. Anal Chim

determination of vanadium (IV) and vanadium (V)Acta, 602, 17-22, 2007.

電子スピン共鳴解析、五価バナジウムの電気分解還元とイオンクロマトグラフィーの組合せによる水試料の四価バナジウムと五価バナジウムの分別定量
目代貴之 1)、池田満雄 2)、河野雅弘 1)、庭野吉己 1)
1)

東北大学未来科学技術共同研究センター〒980-8579 宮城県仙台市青葉区荒巻字青葉 6-6-10
2)

アサヒビール株式会社研究開発本部〒302-0106 茨城県守谷市緑 1-1-21

要旨
バナジウムの抗糖尿病作用が注目されており、バナジウム含有をセールスポイントとする天然水が多数販売されているが、多くの場合バナジウムの存在形態は不明である。これまでバナジウ
ムの分別定量のために二つの方法が開発されている。四価および五価バナジウムを異なる溶媒で抽出し、黒鉛炉原子吸光で分析する方法と液体クロマトグラフィー・誘導結合プラズマ質量分析法である。本研究ではイオンクロマトグラフィーが四価および五価バナジウムの分離に有効であることを示した。次に五価バナジウムが水試料中に存在する場合には、水試料を電気分解することで四価バナジウムに還元できることを示した。最後に、電子スピン共鳴分光法は、四価バナジウムに由来する 8 本のシグナルを検出することができることから、水の電気分解による五価バナ
ジウムの 4 価バナジウムへの還元の検出に有効であることを示した。以上より、我々は、これら三つの方法の組合せは、天然水などの水試料中のバナジウムの分別定量に非常に有効であることを提示した。

キーワード： バナジウム、還元、イオンクロマトグラフィー、電子スピン共鳴33