Determination of Cyanide in Cattle Whole Blood by Microdiffusion Spectrophotometric Method

Abstract

Cyanide is a chemical substance found in plants, pesticides, rodenticides and salts used in the industrial process such as stainless, refining precious metals (gold and silver). Cyanogenic glycoside, one of the chemical forms of cyanides, is naturally presented in many plants including cassava, sorghum and mimosa. Consuming toxic forage is the main cause of acute cyanide poisoning in livestock. In this study, we developed microdiffusion spectrophotometric method to validate the quantitative determination of cyanide in cattle whole blood. Microdiffusion extraction method was performed and the time required to achieve full recovery in the extraction was studied. The optimal time then was used to validate the quantitative determination of cyanide using UV-Vis spectrophotometer at 587 nm wavelength. It was found that the time required to achieve full recovery in the microdiffusion extraction was considerably 2 hours. The established method gave a linearity in a concentration ranging from 0.2 to 4.0 µg/ml. (r=0.997). The limit of detection (LOD) was 0.2 µg/ml while the limit of quantitation (LOQ) was 0.5 µg/ml (102 – 109%Recovery, 2.56 %RSD). The accuracy was evaluated using fortified sample blanks (0.5, 1.0 and 3.0 µg/ml) was 105.16, 97.24 and 92.43 µg/ml, respectively which ranged from 90-108% (standard at 80-120%) and the precision was evaluated by %RSD ranging from 1.73-2.56 (standard at <10) and HorRat ranging from 0.16-0.26 (standard at <2) which all are acceptable.  The method was then used for the determination of cyanide in 48 whole blood samples of cassava pulp-fed dairy cattle. The results revealed that the concentrations of cyanide ranged from 0.24 to 0.54 µg/ml, which were in the same range of normal expectation in blood of most animal species. In conclusion, the microdiffusion spectrophotometric method developed in this study provided accuracy and precision as well as proved to be easy and reliable and it should be suitable for use in blood of other species.