PHOSPHORUS DETERMINATION BY
DERIVATIVE NEUTRON ACTIVATION
ANAL YSIS
Y. M. Scindia, A. G. C. Nair, A. V. R. Reddy and S. B. Manohar
Radiochemistry
Division
Bhabha Atomic Research Centre
Introduction
carrier of O.IM were prepared
P
HOSPHORUS
IS AN
metavanadate
IMPORTANT
hydrate
element in biological, physiological and
environmental
sciences. It is one of the
few elements, which is not amenable
Neutwn
Activation
problem
is
Neutron
Analysis
circumvented
Activation
1987).
meterically
complexed
having superim
(NAA).
using
Analysis
(Ehmann
for direct
(DNAA)
Phosphorus
methnd
is
stoichio-
with a surrogate element
nucleat properties,
which can be
easily assayed by NAA. The pwcedute
selectively
complexing
vanadium
and molybdenum
the
complex
involves
phosphmm
with
in acidic medium as
molybdovanadophosphmic
extracting
This
Derivative
acid
into
(MVPA)
methyl
and
(MIBK)
used
for
(CRMs),
IAEA were dissolved
and
complex
in
order to carry out DNAA. This method is tested
to estimate
phosphorm
in Certified
Reference
Materials and water samples
Results and Discussion
phosphorus
potassium
dihyhwgen
and
this
horn
a standard
mg/ml of phosphorus
Vanadium
was
prepared
phosphate
containing
was prepared
from
(KH2PO4)
0.025
by dilution.
carriers of O.OIM and molybdenum
the stoichiomerry
In the
was kept constant
of phosphorus
emacted
complex
to phosphorus
second
set
density
concenrtation
was vatied. The
was analyzed
spectrophotommL
of optical
(250
in excess (2500 ~g) and
the concenrtation
phosphorus
were
first ser of experiments,
concentration
MVPA
of the
two sets of experiments
~g), with molybdenum
variation
All the reagents used were of AR grade. A stock
of
vanadiom
UV-Visible
Experimental
solution
in 3 ml of conc. HNO3
isobudy
out.
of the MVPA
(freezed
by weight basis.
carried
behavior
A-13
Sample solutions
were rtansferred
complexation
extraction
namely,
ranged
Reference
These were made
complex,
the
de-ionized
up to 25 ml in O.IM. HNO3.
In order to determine
on
using
and 0.5 ml of cone. HCIO,.
MVPA
out
the
animal blood), V-I0 (hay sample) obtained from
and NAA. Studies
carried
of
of phosphorus
fwm 0.02 to 20 ~glg. Two Certified
Materials
4-
Ketone
make. All the standard
were prepared
by UV-Visible
were
Isobutyl
preconcentration
wateL The concentration
ketone (MIBK). The organic phase was amlyzed
spectwscopy
molybdate
Methyl
was of BDH
samples
fwm ammonium
ammonium
respectively.
complex
water
and
using
Fig. 1 shows the
as a function
of
from which vanadiom
miD was found to be 2:1. In the
of
experiment
vanadium
and
phosphorus concentrations were kept constant in
the ratio of 2:1 and the concentration
of
molybdenum
was vatied.
I 72 I--
v
250
~
Me> =c 20
>'9
""9
1 2
0
50
100
150
Amount
200
of
250
P
300
350
400
("9)
Fig. 1. Va,iati", aJabomban" wtth ph"p!"m,
wn"nt"ti,n
-.---2.5
V ~.250
P ~ 75
Fig. 2.
Vatiati,n
aJab"tba""
with nwlybdenum
"9
"9
w",entcatiM'
I
73
I--
Fig. 2 shows the vaeiation
of optical density as
getmanium
function
concentmion.
The
hetempoly
and
ptesent
of molybdenum
mole ratio between phosphmm,
molybdenum
conditions.
Neutron
samples
gamma
ray spectcum
MVPA complex
seen fmm
ate
ray specttometet.
of the n,"tmn
The
actinted
is shown in Fig. 3. It can be
the gamma
chatactetistic
WeCt assayed using
gamma
ray spectcum
tays
of
that the
silicon
also
in the matrix,
analysis. The
known
to
fotm
and that aCt
do not intetfete
execaneous gamma
due to 101Mo_lOlTc
activated
high-tewlution
gamma
vamdium,
was found to he 12,10 undet these
that
acids with molybdenum
in thc
ray peaks ace
(191 keY, 307 keV) and
that of 38Cl (1642 keV)) ptesent as imputitics in
polypmpylene
lineat
cube. The method
analytical
addition
concentmion
tesponse
method
by
was tested fot
ovet
using
range of 0.02-0.20
a
standaed
phosphocus
~g/g.
and
l!
~
~
~
100
:>
~
80
>
ill
~
=
~
.~
U)
C
:::J
a 60
U
>
ill
~
>
ill
~
.,<0
~
0'>
~
40
,,'-"
2'
20
0
0
500
1000
1500
2000
CHANNEL
Fig. 3 Gamma-my spmmm a/th, "cut""
2500
3000
3500
NUMBER
nctiwld MVPA wmph
I 74 I--
FrK4. Plw'pi",w ,"""ntmti,," " 52V"""ty
foond
Table 1 , Rewlr of >tandard water mnple;
to
coefficient(;)
be
linear, with
a conehrion
of 0.998. Table I shows the r"ults
of phosphorus
concentration
in standard
wat"
;amples analyzed. Upto 25-ml of water could be
pteconcenttated
effectively ",ing 5 ml of MlBK.
The mea;mcd
pho;phoru;
namely
(animal
A-13
content in the CRMs,
hlood)
and
V-IO (H,y
sample) are given in Tahle 2. The mOt quoted is
the
standard
deviation
mea;memc<m.
In Fig. 4 "y ",;vity w", plotted
phospho,"s
concenttation.
a a;
The
hetwccn "y ,criviry and phospho,";
The
(lIT)
percent
ttiplicore
srondard
by this method
deviation
(md)
%
,nd
the
percenuge
,.elarionship
repotted
"Iue
is of the order of 4-8 %.
content was
main
func,;on
of
mots
obtained
from
rel,tive
are associated
deviation
with
is 3-7
from
the
Tbe
the counting
I 75 I--
statistics. The absolute limit of deteCtion [LODJ
under Out experimental
irradiation,S
conditions
of 15 min
min cooling and a neutron flux was
of rhe order 10 12
n cm-2 s -1 was calculared
using rhe Cmrie's formula (Cmrie,
19G8)J
Conclusion
A
preconcentrarion
accompanied
(CRM)
procedure
neutron
activation
was developed and used to estimate phosphorus.
The chmcreristi"
Table 2, Results of the analysis of pbosphorus
in the two IAEA Cerrified Reference Materials
chemical
by derivative
in
rerms
of
of (he complex a<e evaluated
rhe
stoichiomerry
and
thc
discrepancy with the reporred literatute observed
is atrributed
ro different acid concentra<ion
conditions.
The method
wide concentration
Using
rhis
detection
rechnique
achicved
experiment
can be applied over a
range
in varying
rhe
is
including
0.07ng.
the
samples can be completed
merhod
is promising
absolute
matrices.
limir
The
counting
of
within 3 hours.
especially
of
entire
thc
The
for water and
biological samples.
LOD
. 2.71
hackground
+ 3.29 ~Cb IL" where Cb is rhe
counts and L, is rhe live time. LOD
was found to be 0.07 ng in an interference
a>odition.
teporred
(1987).
These
values are mperior
by Allen ",d
Allen
and
Hahn,
Hahn
free
to those
and Ehmann
used
(he
tungstophosphoric
acid complex. In this complex
tungsten
surrogare
is the
aCtivated product
phosphorus
element
and
They have reporred a
detecrion limit of 4 ng and I ng respectively.
These values ate much lower rhan rhe mcrhod
using rhe fast neutron
the limit quoted
reaction 3 I P(n,«)'"Al
and
for ion selective electrode
(4
Jig) and spectrophotomctry
(10 Jig) Jig). OUt
value compares better with rhe reporred dara.
The authors a<e thankful (0 Mr R.N. Acharya for
his constructive
of this work.
suggestions
during
the progress
References
rhe
'v W was used to arrivc at the
concentration.
Acknowledgement
1. Currie LA Limirs for Qualirative Derection
and quantitative Derermination, Anal.
Chern. (l9G8) 40: 586.
2.
Ehmann WD, Young RC, Koppcnaa!OW,
Jones WC, and Prasad MN. Derivarive
techniques in Acrivation Analysis,' J.
Radioanal.Nucl. Chern (1987) 112: 71-87.
the Best pap":J'resented in the lit' NJ
'eldat'4't!gaonduring Dlrember 26-29, 1.
I 76 I--
Abautthe autha" ....
M, Yognh M Sdndia obtained hu M.S" in Chtmimy from Mumbai Univmity in 1998. He
joined BARC iu January 1999 0; a Juni"
R"w,h
Fellow und" the Mumbai Uuivmity-DAE
ftllowthip ;cheme and u pmently "",king in Rndi"hemntry Divnian. H;, meaI'Chfie"" are T"t«
Ekment; Det=inatian in Envi'Onmental and BiologicalMatTice>..ing Activation Tethniqun.
D, A. G. C. Nai, joined BARC aft" go-nduatianfrom K"alo Univmity in 1969 and obtained hi,
Ph.D. from Mumbai Univmity in 1989. Hit main am" afintmtt.,e
,ndiochemicalttudm of
flliian and nen"an activatian analyt;,. During the cou"e of thm ,codi",. """al ,ndi"hemical
"pamrian p,aceduet, fi" flliian p'Odum like Mo, Xe, In. Pd, etc. wm developed. Anath" field
wh", he hm ketn intmst i; k, "anda,dized nm"an activatian analy,i, and ,ndima",
appli,atiam. Pmently he ;, engagedin P,ampt Gamma Ray Activation Analy,n te,hnique. He hm
been an !AEA expm to the Ghana Atomi< Eneegy Cammi"ian. Ghana He hm ma'f than 70
publicatiom in int,,"atianal jaurnali and tympo,ia.
D, A. VR. Reddy abtained hi; MS,.
in Chemi"ry in 1974 from S,i Venkate,wam Uni""ity,
Timpati, Andhm Peadnh. He joined Radiochem;,try Div;,ian, BARC, th'Ough the BARC Tiaining
School in 1977 and;, at pment Head. Nu&., Chemi,try Section. Hi, am" af m"I'Ch aCt nuck.,
ji;,ion. nud", ,eactiam, nude., 'pect",copy. heavy element ,hemi,try. activatian analy;;,.
nondmm"ive a;;ay method, and p"pmatian of'pecial ,ndi""i"
tmgm. He hm m"e than 100
publi,atiam to hi, mdit. D, Reddy hm co-auth",d th"e book, and hm edited fi" oolumn. Since
1996. he hm been a memb" af lUPAO
Camm,,"ian an "Radi"hem;,try and Nuck.,
Techniqun': He "",ked during t992-93 in the Inttitut Fu" Ketnchemie, Univmity af Mainz. G=any, on the
,hetnittry of "ama"inide element;. Du,ing 1999-2000, m a technical offi'" in International Atomi, Eneegy Agency,
Vimna, he w"k,d on Radi"h,mi"ry
and Nud,.,
D, S.B. Manoh.,
He Joined
Ifead.
Radio,hemi"ry
"ientife
and
papm
"Exp"immt;
in Radi"hemutry"
we;; in"l"d
in an IAF.A intmampmi"n
he ."ended
con"ibuted
w p"p.,atian
(t989).
D,
Manah.,;,
""tfau,
yMn.
and Allied Scienti",
Divi,ion.
degete in Chemutry
BARC
Ifi,
mea,
"pamtion"
"'"lopment
journali
n"ma"ment;
Ph.D. guUkfa'
comultant;
295
Mumbai
many "ientific
and
titled
than
p"",ding;
100
F,ance
nudem
p"bn,
in rympotia.
colle,ted
du,ing
He hm autho"d
(ekct) of Indian
in the
July,
1987
and envi"nment';
Anadatian
70
a book
99. D,. Manah.,
afiet Chernobyl
tt;u/ent$ have beenawo,"'d
and Pmi"'nt
nudm
He hm publithtd
15-17
in food
;, at pment
"action,
,ndi"aivity
95 and NUCAR
af ,ndwnuclide,
Univmityandfiveafh;,
nudem
technique;.
NUCAR
of Poona in 1965.
School and
fi"ian,
in go-a;; ;ampln
at Cnddeach,
"Mcmu"ment
msodatia",
analy,i"
tWOy (NDA)
ma"
the Univmity
Tiaining
me nudea,
aaicatian
ofmdionudidn
metting
fram
the BARC
af ""m,h
nmt"n
and hm edited the Symp"ium
"pon
th'Ough
af nan-"'ttmcti"
in i""national
the IAEA
of technical
He it a memb~of
Divuion.
mdi"/,,mi,.1
envi'Onment
Analytical technique;,
hn Mmt'"
Radi"hemi,try
'pm,",copy,
In thi, "nnmian
abtained
Ph.D.
accident.
and
hm
lAEA
degete in the
afNuckae
eI"",;",
(IANCAS).
. . -0-.
.
I 77 I--