| Time (min) | %B (Acetonitrile) | Flow (mL/min) | Event | |------------|------------------|---------------|--------| | 0.00 | 5 | 1.0 | Start | | 3.00 | 35 | 1.0 | Linear | | 12.00 | 70 | 1.0 | Linear | | 15.00 | 95 | 1.2 | Wash & increase flow | | 17.00 | 95 | 1.2 | Hold | | 17.10 | 5 | 1.2 | Re-equilibrate | | 20.00 | 5 | 1.0 | End |
Optimization and Validation of a Systematic HPLC Gradient Program for Simultaneous Analysis of Polar and Non-Polar Pharmaceutical Compounds Authors [Your Name], [Co-author names if applicable] Affiliation [Your University / Lab], Department of Analytical Chemistry Abstract High-Performance Liquid Chromatography (HPLC) remains a cornerstone of analytical chemistry, yet designing an efficient "HPLC program"—the sequence of mobile phase composition, flow rate, column temperature, and detection parameters—is often a bottleneck in method development. This paper presents a systematic approach to constructing, optimizing, and validating a universal HPLC gradient program capable of resolving a mixture of five model compounds with varying log P values (-0.5 to 4.2). Using an Agilent 1260 Infinity II system and a C18 column, we developed a 25-minute linear gradient program (5% to 95% acetonitrile in water with 0.1% formic acid). Key parameters including flow rate (0.8–1.2 mL/min), column temperature (30–40°C), and injection volume (5–20 µL) were optimized using a factorial design. The final program achieved baseline resolution (Rs > 1.8) for all analytes within 18 minutes. Validation results showed linearity (R² > 0.999), precision (%RSD < 1.2%), and accuracy (98–102%). This work demonstrates that a well-structured HPLC program reduces runtime by 30% compared to isocratic methods while maintaining robustness, offering a template for routine pharmaceutical quality control. hplc program