Content uploaded by Ochieng Ombaka
Author content
All content in this area was uploaded by Ochieng Ombaka on Jan 20, 2020
Content may be subject to copyright.
International Journal of Development and Sustainability
ISSN: 2186-8662 – www.isdsnet.com/ijds
Volume 8 Number 9 (2019): Pages 627-637
ISDS Article ID: IJDS18081601
Complexometric determination of Nickel
(II) in its synthetic alloys using selected
Hydroxytriazene as Metallochromic
indicator
Ombaka Ochieng *
Chuka University, Chuka, Kenya
Abstract
A simple, rapid and reasonable selective Complexometric technique for nickel (II) determination using some selected
hydroxytriazene as a metallochromic indicator is reported in the present study. The colour change at the end point
was from greenish-yellow/yellow to colourless with sharp end point. The pH ranges were 9.3-9.7, 9.0-9.5, 8.5-9.0, 8.0-
8.5 while temperature ranges were 25-60, 25-60, 25-60, 25-50 and 25-50 0C for reagent (i), (ii), (iii), (iv), and (v)
respectively. Nickel(II) was determined accurately up to concentration as low as 3.0x10-3M for reagents (ii), (iv), and
(v)) while for reagents (i) and (iii) the concentration range could be even lowered to 1.0x10-3M for the determination
of nickel (II). The ions such as Cl-, Br-, CH3COO-, CO32-, PO43-, SO42-, C2O42-, S2O32-, NO2- , SO32-, S2-, HPO42-, F-, NO3, WO42-,
MO7O246-, I-, NH4+, Na+, K+ did not show any interference in the determination of nickel (II) even when they were present
in tenfold excess. Ba2+, Mg2+, Ca2+, were tolerated up to five-fold excess. However Mn2+, Pb2+, Hg2+, Sn2+, Th4+, Cd2+, Co2+,
Cu2+,Zn2+, interfered even at equivalent amount. The method was used to determine nickel in its synthetic alloy with
maximum relative error of 0.78 when using secondary masking agent.
Keywords: Hydroxytriazenes; Nickel; Complexometric Techniques; Synthetic Nickel Alloy; Secondary Masking Agent;
Foreign Ions; Colour Change
* Corresponding author. E-mail address: ombakaochieng@gmail.com
Published by ISDS LLC, Japan | Copyright © 2019 by the Author(s) | This is an open access article distributed under the Creative
Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the
original work is properly cited.
Cite this article as: Ochieng, O. (2019), “Complexometric determination of Nickel (II) in its synthetic alloys using selected
Hydroxytriazene as Metallochromic indicator”, International Journal of Development and Sustainability, Vol. 8 No. 9, pp. 627-
637.
International Journal of Development and Sustainability Vol. 8 No. 9 (2019): 627-637
628 ISDS www.isdsnet.com
1. Introduction
Nickel is a silver-white metal which occurs in nature as a mixture of five stable isotopes (Ombaka, 2018). Pure
Nickel is used as a protective coating for a number of elements and industrial equipment in order to enhance
the value, utility and lifespan of these facilities due to its resistant to corrosion in water or air (Alan, 1992;
Nigam et al., 2015). It’s used in the chemical and food processing industries to prevent iron from being
contaminated. Furthermore, nickel properties can be controlled and varied over broad ranges. Nickel plating
finds numerous applications in industry.
Nickel (II) aqueous solution without strong complexing agents consist of green hexaaquanickel (II) ions.
Nickel (II) forms 4, 5 and 6 coordination numbers with a number of ligands and the structural types includes:
octahedral, trigonal-bipyramidal, square pyramidal, tetrahedral and square. Nickel (II) complexes are
temperature dependent, sometimes concentration dependent and often exist between the above structural
types and this complicates their equilibria (Albert and Geoffrey, 1980).
Nickel based alloys find broad applications due to their unique properties. For example, the high resistivity
and heat resistance of nickel-chromium alloys makes them to be used in electric resistance heating elements.
The nickel-iron alloys have soft magnetic properties which allow them to be utilized in electronic devices and
for electromagnetic shielding of computers and communication equipment. Low expansion behaviour of iron-
nickel alloys caused by a balance between thermal expansion and magnetostrictive changes with temperature
allows them to be used as lead frames in packaging electronic chips and as the shadow-masks in colour
television tubes. The requirement of the thermal expansion during storage and transportation tanks for the
growing liquid natural gas industry can be solved by using iron-nickel alloys. The combination of good
mechanical properties, chemical resistivity and biocompatibility allows nickel based alloys to be used in the
fields of dentistry and implantology (Rader, 2012). The other properties which makes nickel alloys to be
popular comprises of shape memory characteristics of equiatomic nickel-titanium alloys which makes them to
be used as actuators, hydraulic connectors and eyeglass frames. The high strength at high temperatures and
resistance to stress relaxation which contributes wrought nickel-beryllium-titanium to be employed for
demanding electrical/electronic applications. The high conductivity and near resistance make cast nickel-
beryllium-carbon alloys to be utilized for tooling in glass forming operations (John, 1990).
The nonferrous alloys which nickel constitutes either as a major or minor percentage can be classified as
given below: High Nickel alloys {Nickels(nickel 200, nickel 201, nickel 204, nickel 205, nickel 211, nickel 220,
nickel 230, nickel 270, Durannickel alloy 301, permanickel alloy 300), nickel-chromium alloys, nickel-
chromium-iron alloys, Hastelloy alloys, superalloys, nickel-copper alloys}; Low nickel alloys {copper-nickel
alloys, copper-nickel-zinc alloys (nickel-brasses) and miscellaneous alloys i.e. those which do not fall in any of
the categories above which include, Ferrous alloys {wrought steels (low-alloys steels, ultra high strength
structural steels maraging steels, special steels), cast steels and irons{cast steels, cast iron}, stainless steels
{martenistic stainless steels, austenitic stainless steels, precipitation-hardening stainless steels, thermal
expansion and constant modulus alloys, magnetic alloys {magnetically soft materials}, permanent magnets
(Samuel, 1968).
International Journal of Development and Sustainability Vol. 8 No. 9 (2019): 627-637
ISDS www.isdsnet.com 629
Karpet et al. (2015) studied the effect of the nickel concentration on the phase composition, microstructure
and hardness of VCrMnFeCoNi (x=0-3) high entropy alloys and the results revealed that an increase of the
nickel concentration decreases the volume fraction of the beta-phase. Mathew et al. (2017) investigated effect
of Ni-content on phase transformation behaviour of NiTi-20 at % Zr high temperature shape memory alloy and
the findings indicated that, variations in Ni-content contributed to vastly different transformation
temperatures and responds in a drastically different manner to aging treatment at 550 and 600oC. This shows
that, monitoring the levels of nickel in various materials which have applications in the different fields is
necessary.
A large number of classical methods are available for the quantitative determination of nickel. These
methods suffer from interference from ions which are commonly encountered in various materials containing
nickel, which makes them to be inferior to the Complexometric methods (Abraham and Narayana, 1991). Some
of the Complexometric techniques involves the use of masking agents, solvent extraction, demasking, classical
separation, pH adjustment, heating, kinetic masking and removal of anions which makes the procedure not
cost effective and time consuming. Furthermore, metal ion indicators like murexide, solochrome black T and
bromophrogallol red which are commonly used for the determination of nickel are expensive and not easily
synthesized in the normal laboratory. Jingying (2016) reported the use of a new class of chelators and
indicators based on highly selective ionophores embedded in ion-selective nanosphere emulsions with the
emulsion with view of achieving titrations in situ by complete instrumental control, thin layer
electrochemistry. This technique has a weakness pertaining increase of the cost hence a number of developing
countries might not be able to put this technique into practice. In view of the above there is serious need for
continuous search for a technique which is simple, cost effective, less time consuming and can be implemented
in developing countries.
Hydroxytriazenes are a class of metallochromic indicator which coordinate with the number of transition
and non-transition metals via N-OH and –N-N=N- group (Ombaka et al., 2013).
The utility of hydroxytriazene as a metallochromic indicator was demonstrated by the studies carried out
by Krishna et al. (2001) and Ombaka et al. (2013). These studies showed that, metal ions like chromium, iron
can be determined successfully in presence of varying quantities of foreign ions (cations and anions). However,
literature reveals that no attempt has been made to use hydroxytriazene as metallochromic indicator for
determination of Nickel (II) in various material despite its advantages like easy to synthesize and high yield. In
view if this, the research has explored possibility of utilizing hydroxytriazene as metallochromic indicator in
determination of Nickel (II) using EDTA as a titrant in the presence of foreign ions and its synthetic alloys.
2. Material and methods
2.1. Apparatus, chemicals and reagents
pH meter (HI 2211 pH/ OR meter) HANNA Instruments, ultra-pure water equipment (Model MILLI-Q equipped
with Q-POD), analytical grade chemicals, ultra pure water.
International Journal of Development and Sustainability Vol. 8 No. 9 (2019): 627-637
630 ISDS www.isdsnet.com
2.2. Preparations of solutions
2.2.1. Preparation of standard solution of 0.01m Zn2+
Appropriate amount of AR zinc pellets was accurately weighed and then transferred into a 50ml volumetric
flask, dissolved in a minimum amount of concentrated hydrochloric acid. This was followed by addition of a
few drops of concentrated nitric acid in order to speed up the rate of dissolution. The solution was then diluted
to the mark using ultra-pure water (Vogel, 1961; Mendham, 2000).
2.2.2. Preparation of indicator solutions
Murexide indicator solution was prepared by suspending 0.5g of powdered murexide indicator in ultra-pure
water followed by thorough shaking. The undissolved solid was allowed to settle. The saturated supernatant
liquid was used for titration. Xylenol orange indicator solution was prepared by dissolving 0.005g of xylenol
orange in 10ml of ultra-pure water. 0.1M hydroxytriazene indicators solutions were prepared by dissolving
each hydroxytriazene in the required quantity of ethanol (AR) (Vogel, 1961; Mendham, 2000).
2.2.3. Preparation of 0.01M EDTA
1000ml of EDTA stock solution was prepared by dissolving the required quantity of AR disodium dihyrogen
ethylenediaaminetetraacetate dehydrate which was initially dried at 800C for 2 hours in ultra pure water. This
was followed by taking 25ml of the zinc ion solution into a conical flask and diluted with ultra pure water to
about 75ml and 3 drops of xylenol orange indicator solution was added. Then powdered hexamine was added,
with agitation, to the resulting yellow solution until it acquired intense red colour. This solution was titrated
using EDTA solution as the titrant at pH range 6-7. Weaker solutions were prepared by proper dilution of the
stock solution using ultra-pure water (Vogel, 1961; Mendham, 2000).
2.2.4. Preparation of a stock solution of 0.01M Ni2+ and 1M ammonium chloride solution
A 1000ml of 0.01M Ni2+ solution was prepared by taking the required amount of nickel chloride hexahydrate
of B.D.H, AR grade in ultra pure water. A few drops of concentrated hydrochloric acid were added to prevent
hydrolysis. 25ml of this solution was transferred into a conical flask and diluted to 100ml with ultra pure water.
5-6 drops of freshly prepared murexide indicator was added, followed by 10ml of 1M ammonium chloride
solution. Thereafter, concentrated ammonia solution was added drop wise until the pH was about 7 (until the
solution changes to yellow). The solution was titrated using a standard solution of 0.01M EDTA until the end
point was approached and then, the solution was rendered strongly alkaline with about 10ml of concentrated
ammonia solution and the titration continued until the colour changed from yellow to bluish-violet. The EDTA
solution was added drop wise near the end point since nickel complexes react rather slowly with EDTA. 20ml
of 1M NH4Cl was prepared by dissolving appropriate amount of AR NH4Cl in ultra-pure water (Vogel, 1961;
Mendham, 2000).
International Journal of Development and Sustainability Vol. 8 No. 9 (2019): 627-637
ISDS www.isdsnet.com 631
2.2.5. Preparation of 1% tris-buffer and 1.0% perchloric acid solution
1% tris – buffer solution was prepared by dissolving 1.0g of tris-buffer in minimum quantity of ultra-pure
water followed by dilution to 100ml using AR ethanol. 1.0% perchloric acid solution was prepared by adding
1.0ml of perchloric acid to 100ml of AR ethanol (Vogel, 1961; Mendham, 2000).
2.3. Procedures
2.3.1. Effect of pH variation
The titration of nickel (II) was carried out by performing titration at various pH using 1.0% tris-buffer solution
and 1.0% perchloric acid solution. For each of the hydroxytriazene, the optimum pH range was determined
where the colour change at the end point was sharp and most perceptible
2.3.2. Effect of temperature
The effect of temperature was studied by titration of Nickel (II) in the temperature range of 25-600C. The
optimum temperature where the end point was perceptible and sharp for hydroxytriazene was noted.
2.3.3. Optimum concentration range of Nickel (II)
The optimum concentration range for each indicator was determined by titrating 0.001M to 0.01M Ni2+
solution against equimolar solution of EDTA so as to ascertain the minimum concentration of Nickel(II) which
can be determined using hydroxytriazene as indicator.
2.3.4. Interference studies
Interference of 34 diverse ions in various amounts has been studied for Complexometric determination of
nickel (II) with each hydroxytriazene as indicators. For this, titrations of nickel (II) solution containing
2.9355mgs were performed against equimolar EDTA solutions under optimum conditions using
hydroxytriazene as indicator. The same titration was repeated in presence of equivalent amounts of the
interfering species. The ions which did not interfere at equivalent amount were studied for their interference
at five fold excess. Further tenfold excess of these species for those ions only which did not interfere up to five
fold excess. No interference studies were performed beyond tenfold excess. For the preparation of sodium,
potassium and ammonium salts of respective anions used. For the preparation of cation solutions respective
chloride, nitrate salts were used.
2.3.5. Titration procedure
A 10ml of nickel (II) solution was diluted to 30ml with ethanol-water mixture. The corresponding pH was
adjusted with 1.0% tris-buffer solution and 1.0% perchloric acid solution. 5-6 drops of hydroxytriazene were
added which resulted in instantaneous development of greenish-yellow [(reagent number (i) and (ii) or yellow
International Journal of Development and Sustainability Vol. 8 No. 9 (2019): 627-637
632 ISDS www.isdsnet.com
(reagent number (iii), (iv) and (v)]. The solution was very slowly titrated at room temperature with equimolar
solution of EDTA. Close to the end point, one or two drops of indicator were further added to this solution to
enhance the perceptibility of the end point. The end point where colour sharply changed to colourless was
recorded as the end point in all the cases. These results were compared with the results obtained using
murexide as indicator.
3. Results and discussion
Results of the effects of concentration under optimum condition are shown in table 1.
Table 1. Determination of Nickel (II) at different concentrations
Concentration
of
Nickel(II)ions:
Concentration
of EDTA
1.0x10-
3M
1.0x10-
3M
5.0x10-
3M
5.0x10-
3M
3.0x10-
3M
3.0x10-
3M
S/no
Indicator
Colour
change at
the end
point
pH
range
Temperatur
e range oC
Titre value in ml
(i)
3-Hydroxy-3-0-Tolyl-1-
0-
carboxyphenyltriazene
Greenish
yellow to
colourless
9.3-9.7
25.0-60.0
10.0
10.0
10.0
(ii)
3-Hydroxy-3-m-Tolyl-1-
0-carboxy-
phenyltriazene
Greenish
yellow to
colourless
9.0-9.5
25.0-60.0
10.0
10.0
9.7
(iii)
3-hydroxy-3-m-tolyl-1-
p-sulphanato (sodium
salt) phenyltriazene
Yellow to
colourless
9.0-9.5
25.0-60.0
10.0
10.0
9.9
(iv)
3-Hydroxy-3-o-Tolyl-1-
m-
hydroxyphenyltriazene
Yellow to
colourless
8.50-
9.0
25.0-50.0
10.0
10.0
8.8
(v)
3-Hydroxy-3-phenyl-1-
m-
hydroxyphenyltriazene
Yellow to
colourless
8.0-8.5
25.0-50.0
10.0
10.0
9.3
Titration of Nickel (II) solution=10.0ml
Titer value for n=3 obtained using murexide as indicator=10.0ml
The colour change at the end point of reagent (i) and (ii) was greenish-yellow to colourless while for
reagents (iii) and (iv), and reagent (v) was yellow to colourless. The change in colour for reagents (i), (ii) and
(iv) was very sharp whereas for reagents (iii) and (v) the change in colour at the end point was found to be
sharp. The pH range of titration for reagent (i), (ii), (iii), (iv), and (v) were 9.3-9.7, 9.0-9.5, 8.5-9.0, 8.0-8.5
International Journal of Development and Sustainability Vol. 8 No. 9 (2019): 627-637
ISDS www.isdsnet.com 633
respectively. The results revealed that Nickel (II) can be determined with high accuracy in the temperature
range of 20-600C for reagents (i), (ii) and (iii) while for reagents (iv) and (v) requires a temperature range of
25-500C above which colour with indicator faded and therefore clarity at end point diminished.
The minimum concentration of Nickel (II) in the solution which could be determined using each of these
hydroxytriazenes as indicators are summarized in table 1. The results show that Nickel (II) can be determined
accurately using these hydroxytriazenes up to concentrations as low as 3.0x10-3M. In case of reagents (i) and
(iii), concentration range could be even lowered to 1.0x10-3M for the determination of Nickel (II) while for the
remaining three hydroxytriazene end points were not very clear below 3.0 x10-3M. A close examination of the
data presented in table 1, it can be deduced that reagents (i) and (iii) can be used as indicators for
Complexometric determination of Nickel (II) at low concentration hence they have advantages over other the
three hydroxytriazenes used in the present investigation. Further, wide temperatures range, fairly reasonable
pH range and very sharp end point are some of the characteristic features of these hydroxytriazenes as
indicators. The pH range when reagent (iii) is used as indicator is slightly greater than that of reagent (i),
making it to have an extra advantage.
3.1. Effect of foreign ions
The effect of various cations and anions in the determination of Nickel (II) was studied in order to establish
the suitability of the proposed method for quantitative determination of Nickel (II) in nickel alloy. These were
performed by adding different amounts of diverse ions to a solution containing 2.9355mgs of Nickel (II) and
then determined quantitatively using hydroxytriazene as indicator. The tolerance levels of the various foreign
ions studied are show in table 2.
Table 2. Effect of diverse ions in Nickel (II) determination
Diverse
ions
Indicator (i)
Indicator (ii)
Indicator (iii)
Indicator (iv)
Indicator (v)
pH range
9.3-9.7
pH range
9.0-9.5
pH range
9.5-9.0
pH range
98.5-9.0
pH range
8.0-8.5
Mole ratio
Diverse ion:
Nickel(II)
Mole ratio
Diverse ion:
Nickel(II)
Mole ratio
Diverse ion:
Nickel(II)
Mole ratio
Diverse ion:
Nickel(II)
Mole ratio
Diverse ion:
Nickel(II)
Cl-
10
10
10
10
10
Br-
10
10
10
10
10
CH3COO-
10
10
10
10
10
CO32-
10
10
10
10
10
PO43-
10
10
10
10
10
SO42-
10
10
10
10
10
C2042-
10
10
10
10
10
International Journal of Development and Sustainability Vol. 8 No. 9 (2019): 627-637
634 ISDS www.isdsnet.com
I-
10
10
10
10
10
S2032
10
10
10
10
10
NO2-
10
10
10
10
10
SO32-
10
10
10
10
10
S2-
10
10
10
10
10
HPO42--
10
10
10
10
10
F-
10
10
10
10
10
NO3-
10
10
10
10
10
WO42-
10
10
10
10
10
MO70246-
10
10
10
10
10
NH4+
10
10
10
10
10
Na+
10
10
10
10
10
K+
10
10
10
10
10
U6+
1
1
1
1
1
Mn2+
10
10
10
10
10
Ba2+
5
5
5
5
5
Pb2+
-
-
-
-
-
Hg2+
-
-
-
-
-
Sn2+
-
-
-
-
-
Th4+
-
-
-
-
-
Cd2+
-
-
-
-
-
Mg2+
5
5
5
5
5
Ca2+
5
5
5
5
5
Zr4+
1
1
1
1
1
CO2+
-
-
-
-
-
Cu2+
-
-
-
-
-
Zn2+
-
-
-
-
-
- Indicates the ion interfered
Concentration of nickel (II) ions 5.0x10-3M
Concentration of EDTA 5.0x10-3M
Temperature of titration 25-30oC
Titration volume of Nickel (II) ions 10ml
An error of less than or equal to +/- 0.1ml in the recovery was considered to be tolerable. The results in this
table suggest that, the pattern of interference for all hydroxytriazenes was identical. The results further
indicates that ions such as Cl-, Br-, CH3COO-, CO32-, PO43-, SO42-, C2O42-, S2O32-, NO2-, SO32-, S2-, HPO42-, F-, NO3-, WO42-
, MO7O246-, I-, NH4+, Na+, K+ do not show any interference in the determination of nickel(II) even when they were
present in tenfold excess. Ba2+, Mg2+, Ca2+, were tolerated up to five fold excess. However, Mn2+, Pb2+, Hg2+, Sn2+,
Th4+, Cd2+, Co2+, Cu2+, Zn2+, interfered even at equivalent amount. Some of these interference can be avoided by
using appropriate secondary masking agent like guanidine, sodium oxalate, citric acid, fluoride and cysteine
for Hg2+, Pd2+, Mn2+, (sN4+ and Fe3+) and Cu2+ respectively. The interference due to Fe3+, Al3+ and Cr3+
can be eliminated by use of citrate and tartrate. The results of interference demonstrate that the method can
be employed in Complexometric determination of nickel (II) in various nickel alloys using appropriate
secondary masking agent.
International Journal of Development and Sustainability Vol. 8 No. 9 (2019): 627-637
ISDS www.isdsnet.com 635
3.2. Determination of Nickel (II) in synthetic alloy using 3-hydroxy-3-m-tolyl-1-p-sulphanato
(sodium salt) phenyltriazene
Various synthetic mixtures of nickel (II) with manganese, iron, copper, chromium or aluminium were prepared
according to their compositions. The amount of Nickel (II) in the mixture was determined complexometrically
by help of appropriate masking agent using reagent (iii) as indicator. The results of these analyses are
summarized in table 3 below.
Table 3. Determination of Nickel (II) in synthetic mixture of metal ions (n=3)
mixture
Ni present %
Ni found %
Relative error
Ni+Mn+Fe+Cu
66.50
66.67
+0.26
Ni+Mn+Fe+Cu+Cr
76.00
76.31
+0.41
Ni+Mn+Fe+Cu+Cr+Al
60.50
60.79
+0.48
Ni+Mn+Fe+Cu+Cr
36.00
36.28
+0.78
The results of table 3 show that the maximum relative error of the method was 0.78%. The tabulated for six
degree of freedom (N1+N2-2) at the 95% confidence level was 2.447 and tabulated value was found to be
0.0217. From this it can be deduced that, there is no statistical difference between these results and therefore
the proposed method can be used to provide reliable results.
4. Conclusion
Five new metallochromic indicators for direct Complexometric determination of Nickel (II) have been
introduced. The results obtained by these five hydroxytriazenes are comparable to murexide as indicator. The
interference studies clearly revealed that, direct Complexometric determination of Nickel (II) can be carried
out in the presence of a large number of anions and cations using these five hydroxytriazenes with fair
accuracy. Easy preparation, better yield, wide temperature range, fairly reasonable pH range and very sharp
end point are some of the advantages of these five hydroxytriazenes over other metallochromic indicators. The
proposed method can be utilized for the determination of Nickel (II) in its alloys with help of the secondary
masking agent. 3-hydroxy-3-m-tolyl-1-o-carboxyphenyltriazene and 3-hydroxy-3-m-tolyl-1-p-sulphanato
(sodium salt) phenyltriazene can find applications in those alloys which consist of low amount of nickel. The
proposed method does not require heating, readjustment of pH or demasking agent. The proposed method is
simple, rapid and reasonable selective and attribute to the method being attractive to a wide range of
applications.
Acknowledgement
The author wishes to thank the management of Chuka University for allowing me to utilize University facilities.
More thanks also go to the technical staff in chemistry laboratory for their technical support.
International Journal of Development and Sustainability Vol. 8 No. 9 (2019): 627-637
636 ISDS www.isdsnet.com
References
Abraham, J. and Narayana, B. (1999), “Indirect complexometric determination of nickel (II) using 1, 10-
phenanthroline and copper (II) using cysteamine hydrochloride as a releasing agent”, Indian Journal of
Chemistry. Vol. 38A, pp. 628-630.
Alan, G.S. (1992), Inorganic Chemistry, 3rd Edition, Longman Scientific and Technical, pp. 660.
Albert, F.C. and Geoffrey W. (1980), Advanced Inorganic Chemistry. A Comprehensive Text, 4th Edition, John
Wiley and Sons Inc. New York, pp. 798.
Arthur, I.V. (1961), A Textbook of Quantitative Inorganic Analysis Including Elementary Instrumental Analysis,
3rd Edition. Longman Group Limited, London, pp. 415-456.
Gary, D.C., Purnendu K.D. and Kelvin A.S. (2014), Analytical Chemistry, 7th Edition, Wiley and Sons, United States
of America, pp 322-341.
Jingying, Z. (2016), Complexometric Titrations: New Reagents and Concepts to Overcome Old Limitations,
Analyst, Vol. 141 No. 14, pp. 4252-4261.
John, H. (1990), Comprehensive Chemistry, 3rd Edition, Macmillan Educational Ltd, pp. 558.
Karpet, M.V., Myslyvchenko, O.M., Makarenko, O.S., Gorban, V.F., Krapivka, M.O. and Degula, A.I. (2015), “Effect
of nickel on the structure and phase composition of the VCrMnFeCoNi high-entropy alloy”, Journal of Super
Hard Materials: Vol. 37 No. 3, pp 182-188.
Krishna, K.P., Deepika K.G., Sanjay K., Neelam N., Goswami, A.K. and Purohit, D.N. (2001), “Complexometric
determination of chromium (III) from binary and ternary mixture using 3-hydroxy-3-phenyl-1-M-
nitrophenyltriazene as metallochromic indicator”, Asian Journal of Chemistry, Vol.13 No. 1, pp. 299-304.
Mathew, C., Jesse, D., Smith, B.V.D. and Marcus, L.Y. (2017), “Effect of Ni-content on the transformation
temperatures in Niti-20 at % Zr high temperature”, Shape Memory Alloys, Metals, Vol. 7 No. 511, pp. 1-15.
Mendham, J., Denney, R.C., Barnes, J.D. and Thomas, M.J.K. (2000), Vogel’s: Textbook of Quantitative Chemical
Analysis, 6th Edition, Prentice Hall, Pearson Education Limited, England. pp. 371-393.
Nigam, S., Patel, S.K., Mahapatra, S.S., Sharma, N. And Ghosh, K.S. (2015), “Nickel coating on high strength, low
alloy steel by pulse current deposition”, 4th National Conference on Processing and Characterization Material
IOP Conference Serie: Material Science and Engineering Vol. 75 No. 012024, pp. 1-10.
Ochieng, O. (2018), “Utility of 3-hydroxy-3-m-tolyl-1-p-methoxyphenyltriazene as chromogenic reagent for
spectrophotometric determination of nickel in environmental samples”, IOSR Journal of Environmental Science,
Toxicology and Food Technology (IOSR-JESTFT): Vol.12 No.6, pp. 68-76.
Ombaka, O., Musundi, S.W., Gitonga, L.K., Kibara, D. and Oliver, A.N. (2013), “Rapid, economical and selective
complexometric determination of iron (iii) in its synthetic alloys using 3-hydroxy-3-phenyl-1-(2, 4, 6-
tribromophenyl)triazene”, International Journal of Scientific and Engineering Research, Vol. 4 No. 9, pp 140-
145.
International Journal of Development and Sustainability Vol. 8 No. 9 (2019): 627-637
ISDS www.isdsnet.com 637
Radev, D. (2012), “Nickel-containing alloys for medical application obtained by methods for
mechanochemistry and powder metallurgy”, International Scholarly Research Network ISRN Metallurgy, Vol.
2012 No. 464089, pp. 1-6.
Samuel, J.R. (1968), Nickel and Its Alloys. United States Department of Commerce: National Bureau of Standards,
pp. 63-134.
