Purchase mobileappIcon Download our Mobile App
Call Us at 011-40705070  or  
Click to Call
Select your Board & Class
  • Select Board
  • Select Class

I 've chosen the topic, "STUDY O PRESENCE OF INSECTICIDES AND PESTICIDES IN FRUITS AND VEGETABLES" as my investigatory project for chemistry. Could you tell me what i should do for it? pls??

Asked by abinav66(student), on 3/9/11





2. AIM









I place my sincere thanks to my chemistry teacher ********* for her guidance and advices to complete my work successfully. I also thank our principal ********  for providing me all the facilities to finish the project on time.

I also take this opportunity to place on record my deep gratitude to LORD ALMIGHTY for the countless blessings showered on me while doing the work and to complete it.

Last but not least I thank my parents and classmates  for their encouragement and support in my humble venture.



Farmers often use insecticides, also known as pesticides, to keep insects from damaging or eating their crops. In the past decade there has been a tremendous increase in the yields of various crops to meet the demand of overgrowing population, achieved by using pesticides and insecticides. These are chemicals that are sprayed over crop to protect it from pests.  For example, DDT, BHC, zinc phosphide, Mercuric chloride,  dinitrophenol, etc. All pesticides are poisonous chemicals and are used in small quantities with care. Pesticides are proven to be effective against variety of insects, weeds and fungi and are respectively called insecticides, herbicides and fungicides. Most of the pesticides are non-biodegradable and remain penetrated as such into plants, fruits and vegetables . From plants they transfer to animals , birds and human beings which eat these polluted fruits and vegetables. Inside the body they get accumulated and cause serious health problems. These days preference is given to biodegradable insecticides like malathion. The presence of Insecticides residues in even raw samples of wheat, fish, meat , butter etc. have aroused the concern of agricultural administrators, scientists and health officials all over the world to put a check over the use of insecticides and to search for non insecticidal means of pest control.


The Environmental Protection Agency establishes maximum insecticide residue levels in our food, and the Food and Drug Administration and the Department of Agriculture send inspectors to monitor insecticides on the nation 's crops. While growers are required to use only government-approved insecticides in a safe and consistent manner, there can still be residues even after you scrub and rinse the produce. An insecticide test kit allows you to detect the presence of insecticides in fruits and vegetables to get an idea of what you are consuming.



To study the presence of insecticides or pesticides (nitrogen containing) in various fruits and vegetables.



Samples of various fruits and vegetables ,Mortar and pestle , beakers, funnel , glass rod , filter paper china dish , water bath, tripod stand, fusion tube, knife, test tube.


Alcohol, sodium metal, ferric chloride( FeCl 3 ) , ferrous sulphate crystals(FeSO 4 ) ,  dil. Hydrochloric acid (HCl) and distilled water.


The method I used is the brief explanation of Isecticedes, their effects on our daily life and a simple way to test its presence in fruits and vegs.


This is a brief of what you will write as the conclusion



Write  the first paragraph of  ‘Insecticides’  in Wikipedia

A pesticide, according to the Environmental Protection Agency, is “any substance or mixture of substances intended for: preventing,  destroying, repelling, or mitigating any pest.” The EPA continues their definition by adding: “Though often misunderstood to refer only to insecticides, the term pesticide also applies to herbicides, fungicides, and various other substances used to control pests.”


Write the classifications of insecticides on the same page of Wikipedia



Health Effects

Health effects of insecticide on humans depends on the type of insecticide used. DDT was a popular insecticide from the 1940 's that inflicted widespread harm on birds. This insecticide has also been linked to the rise in Parkinson 's Disease. This insecticide has been banned, but some farms continue to use it.

The insecticide dichlorvos can cause skin problems when it has prolonged contact with the skin. This insecticide acts as an irritant and can cause dermatitis. The ester phosphates found in dichlorvos can also be toxic after prolonged exposure. This type of toxicity can lead to nervous system disorders.

Two other insecticides that cause health problems are lindane and methoxychlor. Excessive consumption of lindane is known to cause liver and kidney disorders. Excessive consumption of methoxycholor has been linked to reproductive disorders.


When used properly, insecticide can be very helpful to plants by preventing insects from feeding on these plants. However, excessive use of some insecticides can be phytotoxic to plants and can stunt growth.


Insecticides are designed to reduce the number of insects that can feed on the plants. Some insecticide is designed to kill insects, while other forms of insecticide destroy the insect 's ability to reproduce or prevent the insect from growing. Unfortunately, many of the harmful insects develop resistances to insecticides.


Insecticide often ends up in areas where it is not intended, since insecticide is often delivered from crop dusters and wind can push the insecticide spray in undesirable directions. Insecticide does not immediately leave the area where it is sprayed. Over time, insecticide accumulates and can merge with other chemicals to form more harmful chemicals. These chemicals can end up in the water supply and can cause adverse health effects to humans. However, some forms of insecticide do not harm other species.


With some forms of insecticide, it is difficult to control which animals are harmed. Small mammals, birds and helpful insects are sometimes killed by insecticide, and larger wildlife and fish can also be adversely effected. In addition to the harmful effects of direct contact, insecticide can end up in the food of humans.





·  Take different types of fruits and vegetables and cut them into small pieces separately.

·  Transfer the cut pieces of various fruits and vegetables into separate dishes for each of it separately and crush them using Mortar and pestle to yield their extract.

·  Take each of crushed fruits and vegetables in different beakers and add 100 ml of alcohol to each of these.

·  Stir well and filter the content with a filter paper.

·   Collect the filtrate in separate china dishes and evaporate the alcohol by heating the china dish one by one over a water bath

·  Let the residue dry in the oven.

·  Heat a small piece of sodium in a fusion tube till it melts.

·  Add one of the above residues from the china dish to this fusion tube and heat it till red hot.

·  Drop the hot fusion tube in a china dish containing about 10 ml of distilled water.

·  Break the tube and boil the contents of the china dish for about 5 minutes .

·  Cool and filter the solution with a filter paper and collect the filtrate .

·  To it add 1 ml of freshly prepared ferrous sulphate(FeSO 4 )  solution and warm the contents.

·  Then add 2-3 drops of ferric chloride (FeCl 3 )  solution and acidify it with dilute hydrochloric acid (HCl).

·  If a blue or green precipitate or colouration is obtained it indicates the presence of nitrogen containing insecticides.

·  Repeat the test for nitrogen for residues obtained from other fruits and vegetables and record the observation.




Name of the fruit or


Test for the presence

Of nitrogen

(positive or negative)

Presence of insecticide

Or pesticide residues





















Write a conclusion on :

Just boasting that such projects help students a lot in bla..bla..bla..


1.  Modern’s abc of practical chemistry-XII

1.  Comprehensive practical chemistry – XII

1.  NCERT chemistry  -XII

2.  www.ehow.com

3.  www.icbse.com





Posted by Visakh Vijayan(student), on 31/5/12
Ask a QuestionHave a doubt? Ask our expert and get quick answers.
Show me more questions