HPLC (High-Performance Liquid Chromatography) Analysis

Scope

HPLC analysis covers the separation, identification, and quantification of compounds in solution using a high-pressure liquid chromatography system, with the column chemistry, mobile phase, and detection method selected to suit the analytes and the analytical objective.

Key aspects of the technique include:

• Separation modes – reversed-phase (RP-HPLC, most common), ion-exchange (IEC), size-exclusion (SEC/GPC), normal-phase, and ion-pairing, each suited to specific compound classes
• Detection methods – UV/Vis absorbance, photodiode array (PDA), fluorescence, refractive index (RI), and mass spectrometry (HPLC-MS/MS) for identification and high-sensitivity quantification
• Quantification – peak area compared against calibration standards gives accurate quantitative results for individual components; external and internal standard methods
• Qualitative identification – retention time matching and spectral (PDA, MS) confirmation of compound identity
• Applications range – from major constituent assay (e.g., active ingredient content) to trace-level impurity and contaminant detection
• UHPLC – ultra-high-performance LC using sub-2 µm particles for faster analysis with equivalent or better resolution

Applications

• Raw material and chemical identity/purity – confirming the identity and purity of chemical raw materials, reagents, and intermediates
• Polymer additives and stabilizers – quantifying UV stabilizers, antioxidants, plasticizers, and other additives in polymers and plastics
• Food and beverage analysis – quantifying vitamins, preservatives, sweeteners, contaminants, and nutritional components
• Environmental contaminants – measuring organic pollutants, pesticides, herbicides, and pharmaceutical residues in water and environmental samples
• Cosmetics and personal care – quantifying active ingredients and preservatives
• Stability testing – tracking degradation of compounds over time under accelerated or real-time storage conditions
• Bioseparations – purification and analysis of proteins, peptides, and nucleic acids by appropriate HPLC modes

Benefits

• High resolution, sensitivity, and accuracy – HPLC separates closely related compounds and quantifies them with high precision, essential for purity and trace-level work
• Versatile across compound classes – by changing column chemistry, mobile phase, and detection, the same fundamental technique addresses a very wide range of analytes and matrices
• Quantitative with calibration – peak-area quantification against calibration standards gives accurate concentration results, not just presence/absence
• Definitive identification with MS – coupling to mass spectrometry (HPLC-MS) adds molecular mass and fragmentation data, providing confident structural identification of unknowns and impurities
• Handles non-volatile compounds – HPLC analyzes compounds that cannot be volatilized for GC, covering the large fraction of compounds that GC cannot reach