Quantification of L-ornithine L-aspartate in health supplement by HPLC in combination with o-phthalaldehyde derivative technique

Dietary supplements containing L-ornithine L-aspartate (LOLA) are on the rise. Thus, a simple, reliable method of analysis for determining LOLA has been developed, which helps to control product quality. In this study, a method for determining LOLA in dietary supplements by HPLC in combination with o-phtalaldehyde derivatives (OPA) was developed and validated. The study optimized conditions for extraction of LOLA from the matrix, then derived with OPA and chromatographic separation on column C18. The detection limits and quantitative limits of the method were conducted on low-content real samples, with LOD and LOQ values achieved at 6.0 and 20.0 μg/g, respectively. The method has good recovery (98 – 106%) and repeatability (1.32 – 3.50%) that meet the method performance requirements according to AOAC. The validated method has been applied to analyze LOLA content in dietary supplements at the National Institute for Food Control.