Development of Isocratic RP-HPLC Method for Separation and Quantification of L-Citrulline and L-Arginine in Watermelons

• Main Authors: Abdul Razak, H.R (Author), Adenan, M.I (Author), Md Saad, W.M (Author), Ridwan, R. (Author)
• Format: Article
• Language: English
• Published: Hindawi Limited 2018
• Subjects: Acid content; Arginine; Citrulline; Citrullus lanatus; Detection wavelengths; Freeze dried samples; Juice extracts; Mobile phasis; Positive ions; RP-HPLC method
• Online Access: View Fulltext in Publisher; View in Scopus
• ISBN: 16878760 (ISSN)
• DOI: 10.1155/2018/4798530

Watermelons (Citrullus lanatus) are known to have sufficient amino acid content. In this study, watermelons grown and consumed in Malaysia were investigated for their amino acid content, L-citrulline and L-arginine, by the isocratic RP-HPLC method. Flesh and rind watermelons were juiced, and freeze-dried samples were used for separation and quantification of L-citrulline and L-arginine. Three different mobile phases, 0.7% H3P04, 0.1% H3P04, and 0.7% H3P04: ACN (90: 10), were tested on two different columns using Zorbax Eclipse XDB-C18 and Gemini C18 with a flow rate of 0.5 mL/min and a detection wavelength at 195 nm. Efficient separation with reproducible resolution of L-citrulline and L-arginine was achieved using 0.1% H3P04 on the Gemini C18 column. The method was validated and good linearity of L-citrulline and L-arginine was obtained with R2 = 0.9956, y=0.1664x+2.4142 and R2=0.9912, y=0.4100x+3.4850, respectively. L-citrulline content showed the highest concentration in red watermelon of flesh and rind juice extract (43.81 mg/g and 45.02 mg/g), whereas L-arginine concentration was lower than L-citrulline, ranging from 3.39 to 11.14 mg/g. The isocratic RP-HPLC method with 0.1% H3P04 on the Gemini C18 column proved to be efficient for separation and quantification of L-citrulline and L-arginine in watermelons. © 2018 Rasdin Ridwan et al.