Development of isocratic RP-HPLC method for separation and quantification of L-citrulline and L-arginine in watermelons

• Main Authors: Ridwan, Rasdin, Abdul Razak, Hairil Rashmizal, Adenan, Mohd Ilham, Md Saad, Wan Mazlina
• Format: Article
• Language: English
• Published: Hindawi 2018
• Online Access: http://psasir.upm.edu.my/id/eprint/72263/1/Development%20of%20Isocratic%20RP-HPLC.pdf; http://psasir.upm.edu.my/id/eprint/72263/; https://www.hindawi.com/journals/ijac/2018/4798530/
• Institution: Universiti Putra Malaysia

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 = 0.9956, and , , 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.