Anal. Method Environ. Chem. J. 3 (4) (2020) 40-51

Research Article, Issue 3

Analytical Methods in Environmental Chemistry Journal

Journal home page: www.amecj.com/ir

AMECJ

Solid phase microextraction for organochlorine pesticides

in water samples using MWCNTs-doped polypyrrole coated



electron capture detector

Hamideh Assadollahzadeh

a,*

and

Ebrahim Noroozian

Department of Chemistry, Kerman Branch, Islamic Azad University, Kerman, Iran, P. O. Box 7635131167.

Department of Chemistry, Shahid Bahonar University of Kerman, P.O. Box 133-76175, Kerman, Iran

ABSTRACT

The analysis of organochlorine pesticides (OCPs) residues has

received an increasing attention in the last decades. The solid-phase

microextration (SPME) is a convenient and fast analytical method,

          

semivolatile organic compounds in aqueous samples. In this study,









temperature, ionic strength, desorption time, and desorption

temperature were studied. Under optimized conditions, the detection





, the inter-

day and intra-day relative standard deviations for various OCPs using







. The proposed method

was successfully applied to the analysis of ground water samples with



Keywords:

Organochlorine pesticides,



Polypyrrole composite,

Solid phase microextraction,

Gas chromatography

ARTICLE INFO:









*Corresponding author: 

E-mail: 



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1. Introduction



      

widely used worldwide in order to increase crops

output and enhance quality of products. But most of



in use after evidence of their toxicity and persistence

in the environment . For determination of trace

pesticides/OCPs in complex matrices which contain

      



and high performance analytical instruments. Sample



of the most important steps in analytical processes.

The main conventional methods of sample

     

and solid-phase extraction (SPE) 





of a large amount of expensive and toxic solvents

that can damage the environment. This method

is also time-consuming, tedious, and very often

requires solvent evaporation prior to introduction



of the sample into the analytical instrument. Solid-

phase     , such

as plugging of cartridges, solvent consumption for

       

dispersive

, single-

    

,

   

    have

     

and reduce solvent consumption, etc. However,

solid-phase microextration (SPME) developed

     is a practical

solvent-free alternative for the extraction of organic

compounds. This method is easily automated, it

    meaningfully

decreases the analysis time. In this method, analytes

       



is then introduced into a chromatographic system

for separation and measurement. SPME integrates

sampling, extraction, concentration and sample

introduction into a single solvent-free step. Various



Currently, the improvement in the applications

of SPME is focused on the development of novel



coatings are include polyaniline , polythiophene

, polypyrrole 

(MOFs)     

, metal and metal oxide  , molecularly

imprinted polymer (MIP)   

. 





of phthalate esters from water . In the present

   

composite polymer in direct immersion SPME/GC-

        

water.

2. Experimental

2.1. Chemicals

The twelve organochlorine pesticides namely

    





      



     

    

       

     

    

(Berlin, Germany, http://www.plasmachem.com)

        

      

   Ortho Organizers 

   

      



  

of the mixture of OCPs was prepared in acetone.

     

       

       





respectively. Other reagents used were of highest



all experiments.

2.2. Apparatus

The SPME device was home made. It consisted of

a 

    





piece of the stainless steel wire passing through the





coated with MWCNTs/PPy coating. Electrochemical

polymerization of pyrrole was carried out with a

Behpajuh potentiostat/galvanostat, model BHP





electrode used in the electrochemical process were

 For stirring and

heating the samples during the SPME procedure, a



was used.





Anal. Method Environ. Chem. J. 3 (4) (2020) 40-51

The chromatographic analysis of OCPs was

      

chromatograph (Kyoto, Japan, http://www.

Shimadzu.com), equipped with a split-splitless

BP-



       



min



    



, respectively. The column

         













      

       

GC-MS instrument (Kyoto, Japan, http://www.

Shimadzu.com) equipped with quadrupole analyzer

and electron impact ion-source (EI) was used for

       





2.3. Preparation of composite coating

MWCNTs 

acid. The resultant MWCNTs-COOH was collected



neutralized and was dried at room temperature. The

composite coating of MWCNTs and polypyrrole

was synthesized electrochemically via in-situ



acid oxidized-MWCNTs and the pyrrole monomer.

The deposition was carried out at room temperature.

Stainless steel wire, platinum electrode  

      

and reference electrodes, respectively. The coating

procedure was as follow. The oxidized-MWCNTs

        



min. The composite polymer coating was directly

        



         

       

paper and then washed in acetone while sonicating.

Thermal conditioning of the coated





a helium atmosphere. This removes the volatile

       



2.4. SPME procedure

   



      



       



       



         

     

         

    



vial laced on the magnetic stirrer.

       

the needle, removed from the sample vial and

immediately introduced into the GC injector port for

thermal desorption.

3. Results and discussion

3.1. SPME optimization

In this study, the effect of various parameters on the



and temperature, salting out effect, pH, extraction

time and extraction temperature were studied on a

one-at-a-time strategy. Stirring the sample during

the extraction is also an important parameter. This is

to generate a continuously fresh layer of the sample



      



layer and thus improves the speed of extraction.

Therefore, all the experiments were performed



3.1.1.Desorption time and desorption temperature

Study of desorption processes can provide useful

      

     

carried out in the GC injection port at temperatures

     Figure 1 shows that at

       



        

      







         



         

         



         

the desorption step. Therefore all desorptions were

Fig. 1.









Fig. 2.











Anal. Method Environ. Chem. J. 3 (4) (2020) 40-51

(Fig. 2).

3.1.2. Extraction time

      

involving partitioning of the analytes from the

        

 



        

        





each)



shown in Figure 3. 

areas sharply increase with increases in the extraction

       

     





3.1.3. Extraction temperature

Extraction temperature is a very important

Fig. 3















  







 Figure 4

      









     

    

       

chosen as the optimum extraction temperature for



3.1.4. Ionic strength

Ionic strength can vary the mechanism of mass

transfer of analytes in SPME, depending on the

structure, analyte properties and matrix . In

      

solutes in water decreases in the presence of salts.

Thus, it is expected that the addition of salts should



Fig. 4.





extraction

no sample pH and salt was adjusted or added.



Anal. Method Environ. Chem. J. 3 (4) (2020) 40-51

reason, the effect of this parameter on extraction



carried out from solutions in the presence of NaCl

Figure 5 shows that for most

 improvement in the extraction

       

  

higher NaCl concentrations.

      composite coating is a

       

the surface of pores. It seems that large amounts of

NaCl in the sample solution occupies the surface of

the coating material and have a negative effect on the





without adding any salt to sample solutions.

Fig. 5.





each; 



 no sample pH adjusted.

3.1.5. pH optimization

Further investigations were carried out on pH value

of sample solution. The effect of sample pH on

      







     

solution. Therefore, extraction of OCPs was carried

out using the original solution.

3.2. Method Validation

      

       

were evaluated for the method developed in

       

extracting a series of aqueous solutions of the

 

  



      

  



        



     

      





of determination (r



    

      

     

analyses from mixed aqueous solutions containing







    

         

      











(Table 1). To evaluate the accuracy

of the method, a water sample was collected from



SPME and GC analysis without any pretreatment.

No pesticide was detected in this sample using



  





of each OCP. The percent recoveries



(Table 1).    





       

(Table 2).

Table 1. of OCPs residues in water: 







Compound

LOD





)

Recovery (%)





)

Coeff. Det

RSD%













Intra-day



Inter-day



      

Heptachlor      

     8.8 

Endosulfan I      

      

      

      

Endosulfan II      

      

      

Methoxychlor      



Anal. Method Environ. Chem. J. 3 (4) (2020) 40-51

Table 2. 

 MWCNTs-

Compound References

    







 

     



     

Heptachlor      - 

     - 

Endrin      - 

     - 

  -  -  - -

 -  -  - -

      - 

8.8     - 

      - 

 8    - 

       

      

Endosulfan II       

      

  -  - - - -

 -  - - - -

      - 

     - 

Endosulfan I       

      

Methoxychlor  -  - - - 

 -  - - - 

: Full scan MS



: MS/MS







)





3.3. Real samples

To apply the proposed method in real analysis,

four water samples were collected and stored in





without any pre-treatment. The results found are

shown in Table 3. None of the organochlorine

pesticides were detected in the samples collected

from the campus of Shahid Bahonar University





contaminated. The analysis of real samples

  MWCNTs-PPy for determination



Table 3. The OCPs MWCNTs-PPy  SPME-GC procedure

Location

Noogh Saadi Zarand SBUC

Compound





)

    

Heptachlor    

    

    

    

    

Endosulfan I    

    

    

Methoxychlor    

Endosulfan II 8   



4. Conclusions

The determination of organochlorine compounds

from water samples was successfully performed

    





     

a wide range.       





some of these in the environment. The proposed

     

range, low detection limit and good recovery for

the various OCPs studied.

5. Acknowledgement



     

Shahid Bahonar University of Kerman, Iran

6. References

       

   

toxic effects on living organisms and their

fate in the environment, Interdiscip.Toxicol.,



      



for the preconcentration and determination of



Anal. Method Environ. Chem. J. 3 (4) (2020) 40-51



gas chromatography with mass spectrometry,



       

persistent organochlorine pesticides and





       

   

protected micro-solid-phase extraction of

organochlorine pesticides in environmental

     



 



solid phase extraction for the determination

     

gas chromatography electron capture





 

        

determination of organochlorine pesticides

   

extraction coupled with on-line solid-

phase extraction of high performance liquid

    



        

Recent developments of dispersive liquid

liquid microextraction technique, Chinese J.



     

     



 







     

     

   





       

    



   

low thermal mass gas chromatography-mass





      

     

the extraction of organics from water matrix

samples and their rapid transfer to capillary

      



       



microextraction of organochlorine pesticides

       



       



    

doped polythiophene coating for analysis of

       



 



   

of NiTi wires coated with polypyrrole for the

determination of haloanisoles in water and



    

Polyphosphate-doped polypyrrole coated on



   



    

     

  

    

    



  

     

   

onto a stainless steel wire for direct-

immersion solid-phase microextraction of



    





     

    

   

solid-phase microextraction coatings for

determining organochlorine pesticides in

aqueous environmental samples, J. Sep. Sci.,



      

    

    



      

Highly sensitive and selective hyphenated

technique (molecularly imprinted polymer

solid-phase microextraction-molecularly

imprinted polymer sensor) for ultra trace

analysis of aspartic acid enantiomers, J.



           

     



microextraction of organochlorine pesticides





    

   



     

microextraction of phenols from water



     

Maghsoudi, Solid phase microextraction

      



polypyrrole composite on a stainless steel



     

    



      

   

   

    





     

phase microextraction gas chromatography-

(tandem) mass spectrometry as a tool for

pesticide residue analysis in water sample

at high sensitivity and selectivity with

   

