Quick Detection of Adulteration in Fertilizers

The role of the Fertilizers are very important in the Indian Agriculture. India is the second biggest consumer of fertilizer in the world next only to China. Steadily its use has been increased from 7 million tonnes from 1950-61 to estimated more than 30 million tonnes during 2016-17. The fertilizers are comprised of Urea, DAP, MOP, NPK complexes, SSP, Zinc Sulphate, Copper Sulphate.

With the increase in consumption and its sale price, the problems of quality control have also increased. The Governments whether state or central are making efforts to control the quality of fertilizers.

The demand and the sale price attract the dealers to get quick money by way of adulteration, misbranding, production and sale of non standard fertilizers to the farmers. Resulting the farmers are not getting the standard fertilizers.

In order to check the quality of the fertilizers, the Central Fertilizer Quality  Control & Training Institute (CFQCTI), Faridabad has developed a Quick Fertilizer Testing Kit. Now it is easy to detect adulteration. The farmers as well as dealers can use this Kit to check the adulteration in fertilizers.

To detect adulteration in the Urea, take 1 gm fertilizer in test tube and add 5 ml distilled water to dissolve the material. Add 5-6 drops of Silver Nitrate Solution. The formation of white precipitate indicates that material is adulterated. The non formation of any precipitate indicates that Urea is pure. Similarly for DAP and MOP take 1 gm fertilizer,  add 5 ml distilled water and shake well. Then add 1 ml Nitric Acid and again shake. If it is dissolved and forms semi transparent solution then DAP is pure and if any insoluble material remains, then it is adulterated. Likewise with the use of filter paper, take 1 ml silver nitrate in the filtrate. If the formation of yellow precipitate is also dissolved in 5-6 drops of nitric acid it confirms the presence of phosphate in the material. By mixing small quantity of lime in sample and rubbing, the smell of pungent Ammonia gas indicates the presence of Nitrogen.

By adding 5-6 drops of Cobalt Nitrite  reagent  in the filtrate and formation of yellow precipitate indicates the presence of potassium in the fertilizers. The non formation of the precipitate indicates that the material is spurious.

Sodium Hydroxide (concentrated) to be added and by heating the tube from the side then put moist red litmus paper on the mouth of the tube. Observe the change of the red litmus paper to blue which confirms the presence of Nitrogen and no change indicates the absence of the nitrogen and the fertilizer may be considered suspected. On adding 2 ml of Ferric Chloride-Ammonium acetate reagent and formation of yellow precipitate, which gets dissolved in 5-6 drops of concentrate Nitric Acid confirms presence of phosphate. Non formation of yellow precipitate indicates absence of Phosphate and the sample is suspected. These are for testing the NPK Complexes.

These are quick testing kit and there are limitations also. It is only for qualitative test. Samples failing in the quick test are likely to fail in the detailed laboratory analysis.

For more information and details may contact the Director. The e-mail is: cfqcti@nic.in or phone 0129-2414712/2418484