Development and validation of an effective and sensitive technique for nitrate determination in fruits and vegetables...

This study aims to develop an effective and sensitive HPLC (High Performance Liquid Chromatography) method to determine the nitrate concentration in fruits and vegetables (F & V) using a C₁₈ column (ZORBAX Eclipse XDB-C₁₈, 80Å, 250 × 4.6 mm, 5 μm (Agilent Technologies)) maintained at 40 ⁰ C, a mobile phase made up of methanol and buffer (pentane sulfonic acid sodium salt solution), and a Photo Diode Array Detector (PDA) at 225 nm. The developed method is validated in terms of selectivity, linearity, accuracy, precision, suitability, the limit of detection (LOD), and the limit of quantification (LOQ) according to the European Union Decision 2002/657/EC. The result revealed that a ratio of 30: 70 of the organic modifier methanol and buffer with pH 2.8 shows the highest efficiency. The calibration curve shows linearity with a correlation coefficient (r) of 0.9985. The LOD and LOQ were found to be 2.26 mg/kg and 7.46 mg/kg. The recovery was in the range of 98.96-100.21%. Moreover, the greenness assessment scores of different approaches (eco-scale score of 76, AGREE score of 0.71, and few red shades in GAPI portray) were at a very excellent level. Thus, our developed method is fully validated and can determine the nitrate content in F & V.