What are some tips for making up my mobile phase? - WKB71854

ENVIRONMENT

• Mobile phase preparation

ANSWER

• Be sure to always make the mobile phase up the same way each time using the same technique (gravimetric, volumetric, or online mixing).
• If preparing a mixed mobile phase, be consistent in how you mix the organic with water and/or buffers. Slight variations in preparation can be critical.
• Be sure to use fresh HPLC- or LCMS-grade water, and keep the exposure of open source containers to ambient room conditions to a minimum. Exposure can lead to microbial growth, even in the case of LCMS-grade water.
• Avoid large metal containers for solvents. Use USP Type 1 borosilicate glass, EP Type 1 glass, or ASTM E-438 Type 1 Class A borosilicate glass.  
• Check for particulate material. It is best to pass the mobile phase through a 0.45-µm or 0.2-µm filter or centrifuge, especially if mobile phase is prepared in the lab.

ADDITIONAL INFORMATION