Possible Cause Solution
| Absorption or adsorption of proteins | Change HPLC mode to reduce nonspecific interactions; add protein-solubilizing agent, strong acid or base (with polymeric columns only), or detergent such as SDS to mobile phase. |
| Adsorption on column packing | Increase mobile phase strength to minimize adsorption; for basic compounds add competing base or use base-deactivated packing |
| Adsorption on tubing and other hardware components | Use inert (PEEK), glass-lined, or titanium tubing and flow-path components |
| Chemisorption on column packing | Ensure no reactive groups are present; use polymeric packing; change column type and mode |
| Hydrophobic interactions between stationary | Use short-chain reversed-phase packing; use 300-A pore diameter packing; use hydrophilic packing or ton-exchange media; use hydrophobic interaction chromatography |
| Less than 99% yield for basic compounds irreversible adsorption on active sites | Use endcapped, base-deactivated, sterically protected, high coverage, or polymeric reversed-phase |
| Less than 90% yield for acidic compounds - irreversible adsorption on active sites | Use endcapped or polymeric packing; acidify mobile phase |