Rapid ultraviolet spectrophotometric and liquid chromatographic methods for the determination of natamycin in lactoserum matrix

Two rapid and simple methods were developed for the determination of natamy cin in lactoserum matrix by ultraviolet (UV) spectrophotometry and liquid c hromatography (LC) with diode-array detection. The methods involve protein precipitation with methanol, followed by centrifugation, No cleanup is nece ssary. The applicable concentrations of natamycin in lactoserum range from 2 to 500 mg/L for samples analyzed by both methods. The detection and quant itation limits are 0.07 and 0.23 mg/L, respectively, for the UV spectrophot ometric method and 0.1 and 0.32 mg/L respectively, for the LC method. The m ethods were applied satisfactorily to the determination of natamycin in var ious commercial lactosera, Both methods were validated independently by sta ndard additions and Youden methodologies, which verified their accuracy. On ce the 2 proposed methods were validated independently, the validation of o ne method was carried out with the other.