General guidelines

When performing an HPLC analysis, follow these general recommendations.

• Use high-quality (HPLC- or MS-grade) solvents, buffers, and additives.
• Use high-quality (HPLC- or MS-grade) water.
• Always use solvent filters on tubing in solvent bottles.
• Filter buffers with a 0.45-µm filter membrane.
• Keep concentrated stock solutions to use when preparing working solutions, and, to maximize shelf life, refrigerate them when not using them.
• Do not add fresh buffer to old (a practice known as "topping off"). Doing so can promote microbial growth.
• Keep all solvent lines primed.
• Flush buffers from the system when they are not in use, taking care to avoid using solvents that can precipitate or otherwise react.
• Use 10%-20% organic solvent in water as a storage solvent if you expect the system to remain idle longer than 24 hours.
• Keep the seal wash line primed.
• Monitor the level in the waste vessel to ensure that it can accommodate all the expected waste.

For information about preventing and eliminating contamination, see Controlling Contamination in LC/MS Systems (715001307) on the Waters website (www.waters.com).

Contents

• Carryover