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Graphene for Preconcentration of Trace Amounts of Ni in Water and Paraffin-Embedded Tissues from Liver Loggerhead Turtles Specimens Prior to flame Atomic Absorption Spectrometry

Volume 30, Number 1

Hanie Arbabi Rashid1, Ali Moghimi1*

Department of Chemistry, Varamin(Pishva)  Branch Islamic Azad University, Varamin,   Iran

DOI : http://dx.doi.org/10.13005/ojc/300140

Article Publishing History
Article Received on :
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Article Published : 02 Apr 2014
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ABSTRACT:

A new sensitive and  simple method  was developed  for  the  preconcentration of trace amounts  of Ni  using 1-(2-pyridylazo)-2-naphthol (PAN)  as chelating reagent  prior  to its determination by flame atomic absorption spectrometry. The proposed  method is based on the uti- lization of a column packed with graphene as sorbent. Several effective parameters on the extraction and  complex formation were selected and  optimized.  Under  optimum  conditions,  the calibration graph   was  linear  in  the  concentration  range   of  5.0–240.0 µg L-1    with  a  detection   limit  of 0.36 µg L-1.   The   relative   standard  deviation   for   ten   replicate   measurements    of   20.0  and 100.0 µg L-1  of Ni were 3.45 and 3.18%, respectively. Comparative studies showed that  graphene is superior to other adsorbents  including C18 silica, graphitic  carbon,  and single- and multi-walled carbon  nanotubes for the extraction  of Ni. In the present study, we report the application of preconcentration techniques still continues increasingly for trace metal determinations by flame atomic absorption spectrometry (FAAS) for quantification of Ni in Formalin-fixed paraffin-embedded (FFPE) tissues from Liver loggerhead turtles. The proposed  method  was successfully applied  in the analysis  of  four  real  environmental water  samples.  Good   spiked  recoveries  over  the  range  of 95.8–102.6% were obtained.

KEYWORDS:

Graphene; Solid-phase extraction; Preconcentration;Flame atomic absorption spectrometry; Formalin-fixed paraffin-embedded (FFPE) ; tissues from Liver loggerhead turtles;Ni

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Rashid A. H, Moghimi A. Graphene for Preconcentration of Trace Amounts of Ni in Water and Paraffin-Embedded Tissues from Liver Loggerhead Turtles Specimens Prior to flame Atomic Absorption Spectrometry. Orient J Chem 2014;30(1).

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Rashid A. H, Moghimi A. Graphene for Preconcentration of Trace Amounts of Ni in Water and Paraffin-Embedded Tissues from Liver Loggerhead Turtles Specimens Prior to flame Atomic Absorption Spectrometry. Orient J Chem 2014;30(1). Available from: http://www.orientjchem.org/?p=2428

Introduction

Ni at trace concentrations acts as both a micronutrient and a toxicant in marine and fresh water systems (Izatt et al,1991; Izatt et al,1985; Izatt et al,1995; Blake et al,1996; Arca et al,2001; Ghoulipour et al,2002; Hashemi et al,2001; Shcherbinina et al,1990).This element is needed by plants at only very low levels and is toxic at higher levels. At these levels, Ni can bind to the cell membrane and hinder the transport process through the cell wall. Ni at nearly 40ng mL-1 is required for normal metabolism of many living organisms (Gomes-Gomes 1995; Unger et al, 1979). On the other hand, Ni is an important element in many industries. Thus, the development of new methods for selective separation, concentration and determination of it in sub-micro levels in different industrial, medicinal and environmental samples is of continuing interest. The determination of Ni is usually carried out by flame and graphite furnace atomic absorption spectrometry (AAS) . (Boudreau et al, 1989 ) as well as spectrometric methods (Bruening et al,1991; Mahmoud and Soliman,1997 a) . Solid phase extraction (SPE) methods are the best alternatives for traditional classic methods due to selective removal of trace amounts of metal ions from their matrices. Solid phase extraction determinations can be carried out on different efficient ways. One of the most appropriative performation features of SPE is achieved by using octadecyl silica membrane disks. SPE reduce the use of toxic solvent, disposal costs, and extraction time(Mahmoud et al, 1997 b,45; Mahmoud et al, 1997b).The octadecyl silica membrane disks involves shorter sample processing time and decreased plugging due to the large cross-sectional area of the disk and small pressure drop which allows higher flow-rates; reduced channeling resulting from the use of sorbent with smaller particle size and a greater mechanical stability of the sorbent bed(Tong et al,1990). In our previous attempts, we modified SPE membrane disks with suitable compounds for selective determination of chromium(Dadler et al,1987; Moghimi 2007) and lead(Mahmoud et al,1990).Meanwhile, other investigators have successfully utilized these sorbents for quantitative extraction and monitoring trace amounts of lead(Leyden et al,1976; Moghimi et al,2009; Liu et al,1992), copper (Liu et al,1996; Mishenina et al,1996; Wang et al,1999),  silver( Wanget al,1997; Zhang et al,1982), mercury (Zhouet al,1983; Zargaran et al, 2008), cadmium (Tabarzadi et al, 2010)  , palladium (Shin et al, 2004) , Ni(Moghimi et al,2012) and UO2 (Mahmoudet al,1998 ;Moghimi et al,2006). To ease the retrieval procedure,  the SPE using graphene  as the  absorbent  in  a  column   combined   with  flame  atomic absorption  spectrometry (FAAS)  has  been  demonstrated  by our research group (Wang et al., 2012). We extend its applica- tion to other inorganic analyses. 1-(2-Pyridylazo)-2-naphthol (PAN),  a chelating  agent  which forms  stable  complexes with a number  of metals and  has found  numerous  applications  in trace   element   separation  and   pre-concentration   methods (Narin  and Soylak.,  2003; Shokoufi  et al., 2007), was used to extract  Co  (structure   of  the  Ni-PAN   complex  is shown  in Fig.  1). What  is more,  it possesses a benzene  ring structure. Based  on  this,  the  Ni-PAN  is considered  to  have  formed  a strong p-stacking interaction with graphene when the sample solution   passes  through   the  column  during  which  the  Ni- chelate  is retained.  The  factors  influencing  the  efficiency of SPE  and  FAAS  determination were  systematically  studied. The proposed  method  has been applied  for the determination  of trace amounts  of Ni in water samples with satisfactory  re- sults. It reveals great potential  of graphene  as an excellent sor- bent material in analytical processes for metal ions once again.

 

 

Figure 1 Structural formulae of the Ni-PAN complex. Figure 1 Structural formulae  of the Ni-PAN  complex.

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of trace amounts  of Ni in water samples with satisfactory  re- sults. It reveals great potential  of graphene  as an excellent sor- bent material in analytical processes for metal ions once again.

Methods

Apparatus

A Shimadzu (Kyoto,  Japan) Model AA-6300C atomic absorp- tion  spectrometer  equipped  with  deuterium  background correction  and  a  Ni  hollow-cathode lamp  as  the  radiation source  were  used  for  absorbance measurements   at  a wavelength  of 240.7 nm.  All measurements  were carried  out in an air/acetylene flame. The instrumental parameters were adjusted  according  to  the  manufacturer’s recommendations. A pH3-3C digital pH meter equipped with a combined glass–calomel electrode (Hangzhou Dongxing Instrument Factory,   Hangzhou,  China)   was  used  for  pH  adjustment. The SPE experiments were performed on an Agilent vacuum manifold processing station with a Gast vacuum pump (Tegent Technology  Ltd.  Shanghai,  China).  The empty  SPE columns (3.0 mL) and SPE frits were purchased  from Agilent.

Reagents and materials

Graphite  powder  (50  mesh),  potassium   permanganate (KMnO4), concentrated sulfuric acid (H2SO4),  and sodium ni- trate  (NaNO3) were purchased  from Tianjin Tianda  Chemical Reagent Company  (Tianjin, China). A stock standard solution of Ni at a concentration of 1000 µg mL-1  was purchased from the National Institute  of Standards (Beijing, China).  Working standard solutions were prepared  daily through  serial dilutions of the  stock  solution  with deionized  water  prior  to  analysis. The  chelating  agent,  2.0 g L-1   PAN  solution,  was  prepared by  dissolving  the  appropriate  amount   of  PAN   (Shanghai Chemistry  Reagent  Company,  Shanghai,  China)  in absolute ethanol.  Stock solution  of diverse elements was prepared  from high purity  compounds. Single-walled CNTs  (SWCNTs,  car- bon  purity  >90%, outer  diameter  <2 nm,  length  5–15 µm) and  multi-walled  CNTs  (MWCNTs, carbon   purity  >98%, outer diameter 20–40 nm, length 5–15 µm) were obtained  from the Beijing Chemistry  Reagent  Company  (Beijing, China).

Nitric  acid (0.1 mol L-1) was used to adjust  the pH in the 2–3 range, and ammonium  acetate buffers (0.2 mol L-1) were prepared  by adding  an appropriate amount  of acetic acid to ammonium  acetate  solutions  resulting in solutions  with a pH range of 4.0–5.0. For  a pH range of 6.0–8.0, a phosphate buf- fer solution  (0.2 mol L-1)  was prepared  by adding  an appro- priate amount  of disodium hydrogen phosphate to sodium dihydrogen  phosphate. Ammonium  chloride  buffer  solutions (0.2 mol L-1) were prepared  by adding an appropriate amount of  ammonia   to  ammonium   chloride  solutions,   resulting  in solutions  with a pH range of 9.0–10.0. All reagents  used were of analytical  reagent  grade. Deion- ized water was used in the preparation of all solutions.  All glassware and columns were kept in 10% nitric acid for at least 24 h and subsequently  washed four times with deionized water before application.

Synthesis and characterization  of graphene

Graphene nanoparticles were synthesized according  to our previously reported  study (Wang et al., 2012). The size and morphology  of G was observed  by scanning  electron  micros- copy (SEM) using an S-3000N microscope  and X-ray diffrac- tion (XRD)  measurement  was carried  out  using a Rigaku  D/ max-rB  diffractometer with Cu Ka  radiation. In Fig. 2a, the SEM image shows the graphene  agglomerate,  consisting of al- most  transparent carbon  nanosheets  with  thin  wrinkled  and silk-like structures.  XRD patterns  in Fig. 2b reveal that the graphene  nanosheets’ peak at 2h = 26.2°, which is the charac- teristic peak of graphene  (Rao  et al., 2009).

 

Figure 2 SEM image and XRD pattern.

Figure:2 SEM image and XRD  pattern.



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Column preparation

 Graphene (30.0 mg) was placed in a 3.0 mL SPE column using an upper frit and a lower frit to avoid adsorbent loss. Prior to extraction,  the column was preconditioned with 10.0 mL meth- anol  and  10.0 mL deionized  water,  respectively.  The  column was  then   conditioned   to  the  desired   pH   with  5.0 mL  of 0.2 mol L-1  acetate buffer solution.

Recommended procedure

100.0 mL of the sample solution containing 100.0 µg L-1 of Ni was prepared.  2.5 mL of PAN  (2.0 g L-1) solution  was added and the pH value was adjusted  to 5.0 with acetate buffer solu- tion. The resulting sample solution was passed through  the col- umn at a flow rate of 2.0 mL min-1. After the solution  passed through  it completely,  the column  was rinsed with 5.0 mL of deionised water, and the analytes retained  on the column were eluted with 2.0 mL of 2.0 mol L-1  HNO3 in methanol  at a flow volume, 2.5 mL; eluent type, 2.0 M HNO3 in methanol;  eluent 1; flow rates  of rate  of  2.0 mL min-1.  The  analyte  ions  in  the  eluent  were volume,  2.0 mL;  concentration of Ni,  100.0 µg.L-1 determined  by FAAS.  A blank  was always taken  through  the whole procedure.

Sampling

Tap,  sea, and  river water  samples  used for  the  development of   the   method   were   collected   in   polytetrafluoroethylene (PTFE)  containers  from the Hebei Province. Before the anal- ysis, the organic content  of the water samples was oxidized in the  presence  of 1%  H2O2  and  then  concentrated nitric  acid was  added.  These  water  samples  were  then  filtered  using  a 0.45 lm  pore  size membrane  filter to remove  suspended  par- ticulate matter  and stored  in a refrigerator in the dark  before analysis.

Analysis of sample paraffin-embedded tissues from liver loggerhead turtles

specimens: Selected areas from fresh frozen tissues from liver loggerhead turtles specimens were sliced in three pieces (numbered as 1, 2 and 3) of approximately 10 mm × 5 mm × 2 mm each. Sets of pieces of set 1 (controls), were placed into a vacuum chamber at 50 ºC overnight to dry (until a constant weight was obtained) and the sets 2 and 3 were subjected to the standard 10 % buffered formalin fixation and paraffin embedding31 histological process using a tissue processor (Tissue-Tek VIP, Sakura Finetek USA Inc., Torrance, CA). After the paraffin embedding process, tissues were subsequently excised from the blocks with a titanium knife and deparaffinized in xylene at 55 ºC for 1 h in the tissue processor (the set 2), or with hexane at 20 ºC for 1 week with frequent changes of the solvent in handling-based procedure (the set 3). Xylene was of a grade routinely used for the FFPE process and hexane was of ”Optima” grade (Fisher Scientific). Upon deparaffinization, the tissue samples were dried in a vacuum chamber until constant weight was obtained. Each dried sample (of the sets 1-3) was divided into three portions (5-10 mg each) to be further analyzed as triplicates.

 

 Figure 3 Effect of pH on the absorbance of Ni obtained from SPE- FAAS. Extraction conditions: water sample volume, 100.0 mL; PAN Figure: 3 Effect of pH on the absorbance of Ni obtained from SPE- FAAS. Extraction conditions: water sample volume, 100.0 mL; PAN 

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Results and discussion

Effect of pH

Sample pH had a critical effect on the adsorption of target compounds  by  affecting  the  existing  form  of  target   com- pounds,  the charge species and density on the sorbents  surface (Jiao et al., 2012). A series of experiments  was performed  by adjusting  the pH from 2.0 to 10.0 with nitric acid, ammonium acetate,  phosphate and ammonium  chloride.  The results illus- trated  in Fig. 3 reveals that  the absorbance is nearly constant in the pH range of 5.0–7.0. The progressive decrease in the extraction  of Ni at low pH  is due to the competition  of the hydrogen ion with the analyte for the reaction with PAN. Accordingly, pH 5.0 was selected for subsequent  work and real sample analysis.

Results and discussion

Effect of pH

Sample pH had a critical effect on the adsorption of target compounds  by  affecting  the  existing  form  of  target   com- pounds,  the charge species and density on the sorbents  surface (Jiao et al., 2012). A series of experiments  was performed  by adjusting  the pH from 2.0 to 10.0 with nitric acid, ammonium acetate,  phosphate and ammonium  chloride.  The results illus- trated  in Fig. 3 reveals that  the absorbance is nearly constant in the pH range of 5.0–7.0. The progressive decrease in the extraction  of Ni at low pH  is due to the competition  of the hydrogen ion with the analyte for the reaction with PAN. Accordingly, pH 5.0 was selected for subsequent  work and real sample analysis.

Influence of the amount of PAN

The effect of the amount  of PAN on the absorption was stud- ied using various volumes of the reagent ranging from 0.5 mL to 3.5 mL. The signal of Ni was increased with the increase of PAN  volume  up  to  2.0 mL,  and  then  kept  constant.  Hence, 2.5 mL of 2.0 g L-1  PAN  solution  was chosen to account  for other  extractable  species that  might potentially  interfere  with the assaying of Ni. sample and eluent solution, 2.0 mL min-1

Effect of flow rates of sample and eluent solution

The efficiency of metal preconcentration essentially depends on the flow rate of the sample solution to pass through  the micro- column, whereas the flow of eluent solutions  affects the recov- eries. The time taken  is also a considerable  factor.  Therefore, the effect of the flow rate  of the sample and  eluent  solutions on the recoveries of Ni on graphene was examined in the range of 0.5–5.0 mL min-1. The flow rate  of the sample and  eluent solutions had no obvious influence on the quantitative recover- ies of analytes  at the range of 0.5–4.0 and 0.5–2.0 mL min-1, respectively. A 2.0 mL min-1 flow rate of the sample and eluent solutions  was chosen in subsequent  experiments.

Breakthrough volume

The measurement  of breakthrough volume is important in so- lid phase  extraction  because breakthrough volume represents the  sample  volume  that  can  be preconcentrated without  the loss of analyte during elution of the sample (Mester and Stur- geon, 2003). The breakthrough volume of the sample solution was tested  by dissolving  10.0 µg  of Ni  in different  volumes (25.0–1000.0 mL)  and  the  recommended   procedure  was  fol- lowed. It was observed that Ni was quantitatively recovered when the  sample  volume  was less than  400.0 mL.  When  the sample   volume   exceeded  400.0 mL,   the  recovery   was  de- creased.   The  preconcentration  factor   for  preconcentration and extraction  is calculated  by the ratio  of the highest sample volume for analyte (400.0 mL) and the lowest final eluent vol- ume (2.0 mL). In the present  study the possible preconcentra- tion factor  was 200.

Adsorption capacity

In  order  to  evaluate  the  adsorptive  capacity  of graphene,  a batch   method   was  used.  100.0 mL  of  solution   containing 1.0 mg of metal ion at pH 5.0 was added  to 30.0 mg sorbent. The  mixture  was filtered,  after  shaking  for  10 min.  10.0 mL of the supernatant solution was determined  by FAAS. The capacity of the sorbent  for Ni was found  to be 20.6 mg g-1.

 

Table 1 Effect of type and concentration of eluting agent on recovery of Ni. Table1: Effect of type and concentration of eluting agent on recovery of Ni.
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Eluent type and its volume

In order  to choose the best solvent for desorption  of the ad- sorbed analytes on graphene, many reagent solutions were investigated. The results were given in Table 1. As can be seen, the  recoveries  of  Ni  were  not  so  satisfactory   when  HCl, HNO3,  H2SO4, CH3COOH and NaOH  were used as eluents solely. Good  quantitative recovery for analyte ions could be obtained  with 2.0 mol L-1  HNO3  in methanol.  The effect of eluent volume on the recovery of Ni was also studied by using 2.0 mol L-1  HNO3 in methanol;  it was found that quantitative recoveries could  be obtained  with 2.0–4.0 mL of 2.0 mol L-1

 

 Table 2 Effect of interfering ions on the recovery of 100.0 µg L-1 Ni in water samples using SPE-FAAS. Table 2: Effect of interfering  ions on the recovery of 100.0 µg L-1  Ni in water samples using SPE-FAAS.

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Table 3.  Analytical  results of Ni determination (dissolved fraction)  in certified reference materials  and spiked natural  water samples with the SPE-FAAS  method  (n = 3). 

 

Table 3.  Analytical  results of Ni determination (dissolved fraction)  in certified reference materials  and spiked natural  water samples with the SPE-FAAS  method  (n = 3).
Sample Ni 2+ added (µg) Ni 2+determined(ng.mL-1) ICP-AES
GSBZ 50,030-94 (µg L-1) 0.0 28.53 (2.0) 28.20(2.0)
Tap water(Tehran, 20January, 2014) 0.010.0 1.74(2.0)a11.95(2.6) NDb11.6
Snow water(Tehran , 5 February ,2014) 0.010.0 4.84(2.1)14.96(2.4) ND14.6
Rain water (Tehran, 20 January, 2013) 0.010.0 2.65(2.3)12.46(2.3) ND12.3
Sea Water Tehran , 16 February ,2013) 0.010.0 12.65(2.4)22.96(2.0) 12.423.1
Development of a methodology for the determination of   Ni 2+ in FFPE tissue 0.010.0 N.Db9.95(2.2) N.Db10.05(2.5)
a Values in parentheses are %RSDs based on five individual replicate analysisb Not detected. 

 

5.0  to   240.0 µg L-1    for   Ni.   The   calibration   equation   is A = 3.16 · 10-3C + 0.0042 with  a  correlation coefficient  of 0.9992, where A is the atomic  absorbance of Ni, obtained  by peak height, in the eluent at 240.5 nm and C is its concentra- tion  in the sample  solution  (µg L-1).  The  limits of detection and  quantification defined  as 3SB/m  and  10SB/m  (where SB is standard deviation of the blank and m is the slope of the cal- ibration  graph)  were 0.36 and  1.20 µg L-1,  respectively.  The relative  standard deviation  (RSD)  for  ten  replicate  measure- ments   of  20.0  and   100.0 µg L-1    of  Ni  were  3.45%   and 3.18%, respectively.

Analytical application

The proposed  method was used for the determination of Ni in several water samples. The results, along with the recovery for the spiked samples, are given in Table 3. The recoveries for the addition  of different  concentrations of Ni  to  water  samples were in the range  of 95.8–97.6%.  To verify the accuracy  of the  proposed  procedure,  the  method  was used  to  determine of the content of Ni in the National Standard Reference Mate- rial for Environment Water (GSBZ 50030-94) after the appro- priate  dilution and development of a methodology for the determination of   Ni 2+ in FFPE tissue .  The results for this test are presented  in Table 3. A good agreement between the determined values and the certified values was obtained.

Comparison with other sorbent materials

In this work,  we report  a comparison  between graphene  with several   commonly   used   reserved-phase    sorbent    materials including  C18  silica,  graphitic  carbon,  and  CNTs.  For  this purpose,  the  same amount  (30.0 mg) of different  adsorbents was packed in 3.0 mL SPE columns. The columns were loaded with 100.0 mL of sample solutions  containing  100.0 µg L-1  of Ni. All the work is done under the optimized conditions  of graphene  selected above.  The C18 silica was evacuated  from a Supelclean LC-18 SPE tube (Shanghai  Chuding  Instrument Company,   Shanghai,   China).   The  Ni  in  the  flow-through, washing solution,  and eluate were all determined. As shown  in Table  4, the graphene-packed column  yields the highest recoveries (96.2%)  among  the studied  adsorbents. This  result  definitely  justifies  the  worth  of  graphene  as  an SPE adsorbent. Ni  could be detected  in the flow-through and washing solution  after loading  on a C18 column, indicat- ing that  30.0 mg C18 silica is insufficient  for the retention  of  chelates. To obtain  acceptable  results with C18, more  adsor- bent should  be packed  in the column  to enhance  the adsorp- tion  capacity.  For  instance,  with a C18 column  packed  with 300.0 mg C18 silica, the  recoveries  of  Ni  can  reach  93.5%. However, increasing the adsorbent amount  will add to the cost of analysis and is unfavorable for instrument  miniaturization. Graphitic carbon  performed  even more  poorly  than  C18. It was proposed  that  graphitic  carbon  did not give the expected extraction  efficiency because of its large size and blank volume and less active sites for adsorption (Zhou et al., 2006). So it is noted that adsorption capacity of the adsorbents  was generally in the following order: Graphene >C18 silica >Graphitic car- bon.  For  MWCNTs, the recovery was approximately 78.3%, which  is evidently  inferior  to  that  of  graphene.   Recoveries for  columns  using  SWCNTs   were  higher  than   MWCNTs, but still inferior to graphene.  No Ni was present  in the flow- throughs and washing solutions for MWCNTs and SWCNTs, indicating  that  CNTs  also have good  sorption  capacities  for Ni.  Thus,  the lower recoveries on  CNTs  should  be ascribed to  extremely  stable  adsorption and  incomplete  elution. Increasing the volume of the eluent solvent can improve the recovery, e.g., with 5.0 mL HNO3 as eluent solvent, the recov- ery of Ni on SWCNT  column can reach 92.3%. Nevertheless, increasing the volume of the eluent solvent will reduce the pre- concentration factor. The advantage  of graphene  over C18 and graphitic  carbon mainly  lies in its higher  sorption  capacity.  In addition,  com- pared  with CNTs,  achieving complete  elution  with graphene is more facile. The above experimental results indicated that graphene  is a very promising  adsorbent material.

 

Table 4 Comparison of the performance of graphene with several other adsorbents (C18 silica, graphitic carbon, SWCNTs, and MWCNTs) for the SPE of Ni. Table 4 Comparison of the performance of graphene  with several other  adsorbents  (C18 silica, graphitic  carbon,  SWCNTs,  and MWCNTs) for the SPE of Ni.

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conclusions

In conclusion, the proposed  method reveals the great potential of  graphene   as  an  advantageous  sorbent  material  in  SPE. Using Ni as model analyte, the graphene-packed SPE columns showed reliable and attractive  analytical performance in the analysis  of  environmental water  samples.  Higher  recoveries were  achieved   with  graphene   than   with  other   adsorbents including  C18 silica, graphitic  carbon,  and  CNTs,  owing  to the large surface area and unique chemical structure  of graph- ene. Some other advantages  of graphene  as an SPE adsorbent have also been demonstrated, such as high sorption  capacity, good  reusability,  and  fine reproducibility. Although  the  ob- tained  results of this research  were related  to the Ni determi- nation,   the  system  could  be  a  considerable   potential   guide for the preconcentration and determination of other  metals.

Acknowledgements

The authour wish to thank the Chemistery Department of Varamin(Pishva)  branch Islamic Azad University for financial support.

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