Assessment of Amitraz Residue in Milk Samples in Uasin Gishu and Nandi Districts


  • B. L. Musavi School of Science, Department of Chemistry and Biochemistry, Chepkoilel University College, P. O. Box 1125, Eldoret, Kenya.
  • S. T. Lutta School of Science, Department of Chemistry and Biochemistry Chepkoilel University College, P. O. Box 1125, Eldoret, Kenya.
  • M. O. Okoth School of Science, Department of Chemistry and Biochemistry Chepkoilel University College, P. O. Box 1125, Eldoret, Kenya.


Amitraz residue, milk, farmer’s, Uasin Gishu, Nandi


Analysis of amitraz residue in milk samples, in Uasin Gishu and Nandi countiess has been done. The samples were randomly obtained from cows’ farmers using amitraz as a spray and also milk vendors around Eldoret town. Levels of amitraz residue were compared with MRL and ADI levels given as 0.05ppm by WHO, FAO and EPA. GC/MS was used for qualitative analysis. GC/ECD was also used for quantitative analysis. Derivatization of the extractable of amitraz residue from spiked standards and milk samples was done with heptafluorobutyric anhydride, to enhance electron capture for greater sensitivity with ECD. Before spraying amitraz residue was low. After spraying there was a sharp increase, then sharp decrease followed by gradual decreases in concentration of amitraz residue. The average concentration of amitraz residue from milk samples ranged from 0.02 - 0.05 ppm with milk having amitraz residue falling below 0.22ppm. It was found out that 39.58% had an average of amitraz concentration below MRL. About 10.42% of samples had the range of 0.06-022 ppm, which is above the MRL, while about 8.33% had 0.05ppm MRL. The effect of optimising and derivatization gave good extraction conditions, which were 2 hours reflux times, 60 minutes water bath periods and 50oC water bath temperatures. Detection limit using 3x s.d blank method was found to be 0.016 ppm which is below the MRL. The percentage recoveries of amitraz residue were above 80% the accepted value showing how effective extraction was. The butter fat content was found to fall in the range of 2.00 - 5.17% with most milk having butter fat content falling in the range of 2.50- 3.50%. A correlation between butter fat content and amitraz concentration was found to be 0.957 thus positive. The final result had an implication on the usage of amitraz product and its toxicity effect on the consumers. Hence risk mitigation had to be taken in account.


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How to Cite

Musavi, B. L., Lutta, S. T., & Okoth, M. O. (2012). Assessment of Amitraz Residue in Milk Samples in Uasin Gishu and Nandi Districts. East African Journal of Pure and Applied Sciences, 2(1), Pg 73–103. Retrieved from