|
|
Guidance:
Using Tough Dirty and Complex Samples and/or Mobile Phases
Maintenance
of HPLC/UPLC -
Optical Detection
- Sonication of all stainless-Steel
filters in the system:
- 10% acetic acid in 45:45 water:Methanol followed by methanol then water (5 min each)
- In worse cases use 10% nitric acid in
water.
It
is
better to just replace the reservoir filters
- Use "wash" vials: injection of full loop volume after each set of tough samples:
VARIOUS OPTIONS:
1. 20% acetic acid in water (for salts)
2. 5% NH4OH (for salts)
3. IPA (for lypophilic compounds)
4. Acetone (for polymeric residues)
5. DMSO:H2O (for bio-residues)
6. 1 mM EDTA (for metallic residues or chelating agents such as amino acids).
- Purge injector in the end of every sample set using water/MeOH/MeCN mixtures according to the method
- Wash the detector cell (using union or column's bypass) with the appropriate wash solution
-
Water (for salts)
-
Methanol or isopropanol (for oily residues)
-
10% acetic acid in water (for salts)
-
0.1 mM EDTA (for chelating agents)
Routine
maintenance of HPLC-MS or ELSD
- Reservoir filters sonication of bottle A (H2O with FA) once a month
- In-line filter in the pump, sonication once a month
- Water for LC-MS should be clean of residues (check supplier)
Preventative measures:
- Use "wash" vials for injection of full loop volume after each set of tough samples:
OPTIONS:
1. 20% acetic acid in water (for salts)
2. 5% NH4OH (for salts)
3. IPA (for lypophilic compounds)
4. Acetone (for polymeric residues)
5. DMSO:H2O (for bio-residues)
6. 1 mM EDTA (for metallic residues or chelating agents such as catalysts).
- Purge injector in the end of every sample set: (Masslynx: Use an inlet method with purge injector in the shutdown method)
Follow-up
- Inject 100ul 50:50 MeCN:H2O after every tough sample to wash contamination
- Inject blank (sample’s solvent) after every concentrated sample
|
|
