• Buy HPLC grade solvents, including H₂O.
• Record lot no.
• Sparge all solvents, particularly water
• Check H₂O for Organic contaminants.
• Pump 100ml of H₂O through RP-18 column; then use MeOH gradient, UV-254.
• Compare peak areas
• Filter all buffers. (use 0.5 mm filters).
• Add 100 ppm of sodium azide to aqueous buffers .

• Sample clean-up
• Filter and centrifuge
• Solvent Extraction
• SPE (Solid Phase Extraction)
• Use a sample solvent equal to or weaker in solvent strength than the mobile phase. 
• Avoids precipitation
• Improves resolution
• Use a dilute solution if possible (1% or less in 20 or 50 μl loop).

• For increased pump life, keep system pressure  below 2000 psi. 
• Biggest enemy of pump is strong buffer.
• Always wash out buffer thoroughly before shutting down.
• Use dilute buffers (0.01 M or weaker).
• Wash, sonicate (if necessary replace)pump seals every 6 months. Otherwise store in 50:50 MeOH : Water, replace every year.
• Always purge the pump first when beginning with a new solvent system;
• Dedicate a pump for use with solvent systems that are either polar or nonpolar.
• Salt deposits at connections indicate leaks.
• Never run a pump when it is dry.  The pistons and seals must first be wetted by priming the pump.
• Methanol is the best choice for priming because it “wets” surfaces easily.
• Air,dirt and buffers are your pump’s biggest enemies.

• Purchase from major reliable manufacturer.
• Test column characteristics.
• A. Inert mix for channels ( toluene)        
• B. Efficiency, use toluene-plate height should be 21/2 ´ (or less) the particle diameter.  If not return column.
• C. Inject basic compounds( pyridine) to test for acidic sites.
• D. Pore diameter, should be 3 times the solute diameter. (70-120 Å).
• Minimize pressure surges and mechanical shocks.
• Use column temperatures < 60˚C.
• For overnight and storage, purge out salts and buffers.  Store in acetronitrile/water.
• Store column (GPC, GFC, IEC) in recommended solvent.
• To prevent sample adsorption :
• Use guard columns.
• Sample clean-up (filter, SPE, SFE).
• Frequent column purge with strong solvent. Use hot water if buffers were used.
• Regenerate column (reverse flush new columns).
• To prevent chemical attack on columns :
• Choose separation conditions more carefully
  (pH, Temp., Solvents)
• Measure pH of sample (neutralize if necessary).

Symptoms of a dying column

• Pressure increase.
• Tailing/Splitting peaks.
• Loss in plate number.
• Decrease in retention.

• Pump pressure increases /Severe Tailing/Double peaks
• Replace inlet frit.– filter cloudy samples
• use in-line filters.
• Check for precipitation at column head. Wash with hot water or strong solvent, 20 column volumes.

• Electrical problems - call manufacturer.
• Old (burned out) lamp- replace.
• Measure sensitivity regularly with standards, replace lamp before it burns out.
• Leaks, air bubbles - sharp spikes.
• Dirty cell window - low sensitivity (wash cell with 5% HNO₃ for 20 minutes, flush with lots of H₂O).
• Do not clean columns through detector.