As per USP guideline <1664>, assessment of leachables for parenteral formulations associated with primary packaging/delivery system is being mandatory. Leachables are foreign organic and inorganic chemical entities that are present in a packaged drug product because they have leached from either direct or indirect contact of formulation under normal conditions of storage and use or during accelerated drug product stability studies. Leachables can potentially affect drug product efficacy, safety and quality hence the quantitative determination of leachables impurities in parenteral formulation is essential. UPLC-HRMS (QToF) is used for detection and quantitation of organic non-volatile leachables at ppb level. Full scan method with scan range from 100 m/z to 1500 m/z was developed at 50% AET level with concentration of 0.075 ppm. This research paper presents the development and verification of screening method for determination of non-volatile organic leachables from complex matrix containing castor oil as excipient in parenteral formulation.