Optimization and Validation of Analytical Method for Determination of Some Organic Disinfectants in Some Agricultural Products

Abstract

In the present study, simple and reliable method for the analysis of some quaternary ammonium compounds (QACs) was developed, optimized and validated to meet the requirements of some agricultural products (green beans, orange and olive) safety. QACs in samples were extracted with acetonitrile and identified by liquid chromatography tandem mass spectrometry (LC-MS/MS) with gradient mobile phase (10 mM ammonium formate solution in methanol/water (1:9)) and pH 4±0.1. The method was validated with average recovery ranged from 78 to 117% and coefficient of variation (CV %) less than 10 %. The performance of the proposed method was checked with two samples from the Food Analysis Performance Assessment Scheme (FAPAS) as an external quality control; the Z-score (Z) was found within acceptable range │Z│≤ 2. The measurement uncertainty is expressed as expanded uncertainty and in terms of relative standard deviation (at 95% confidence level) is ±19%. This method is suitable for laboratories engaged daily in routine analysis of a large number of samples.

Keywords: QACs; LC-MS/MS; validation. Contact person: E-mail address: Khalil62@yahoo.com, Telephone number: +201015473835