Determination of Insulin Concentration in Camel Milk Using Ultra Violet –Visible Absorption Spectroscopy

ABSTRACT: Camel milk contains sufficient levels of insulin and does not form the coagulum in the stomach preventing degradation of insulin and act as an effective vehicle to take the milk insulin unchanged to the intestine. In present study direct spectroscopy and standard addition method, well-known methods in analytical chemistry were used for determining insulin concentration in camel milk. The concentration of insulin was determined by UV absorption measurement at wavelength of 276 nm. The linear range for calibration curve in direct spectroscopy was 2 to 8 units/liter insulin solution indicating good agreement with Beer-Lambert law. The camel milk was centrifuged and upper clear solution was separated. According to calibration curve, insulin concentration was determined by direct spectroscopy. In standard addition method, upper clear solution and sufficient amount of distilled water were mixed with insulin standard solution to prepare solutions for Uv-Vis spectroscopy. The insulin levels in upper clear solution were determined; 17.91± 0.40 and 18.65 ± 0.38 units/ liter, using standard addition method and direct spectroscopy, respectively. Both methods are capable of being used in determining insulin concentration in camel milk. However, it is suggested to use standard addition method for measuring insulin concentration due to decreasing matrix error during determination