Preventive Maintenance
Liner and/or insert care
Liner and/or insert care
Regardless of the inlet system, inlet inserts and/or liners must be kept clean for optimum performance, particularly their interiors from which contamination may enter the column and/or interact with sample components.
Note: Excessive contamination anywhere on an insert or liner should be avoided, particularly its interior.
Ideally, clean replacement liners and/or inserts should be available for quick exchange when necessary.
Liners and/or inserts are treated differently, depending upon whether they are of glass or metal.
Glass inserts
CIf a split insert (for a split/splitless, or split•only, capillary inlet system) is to be cleaned, remove its packing.
CBecause contamination is often in the form of carbonaceous materials (insoluble in organic solvents), immersion in concentrated chromic acid (for up to 24 hours) is recommended as the first cleaning step.
WARNING Concentrated chromic acid is highly toxic and corrosive. Observe proper safety precautions.
CAfter chromic acid, inserts are rinsed in distilled H1O, CH2OH (methanol) and (CH2)1CO (acetone), and then dried thoroughly in an oven at 105^C.
CAfter washing and drying, a small brush or suitable wire may be used to dislodge solids from interior surfaces, followed by using compressed, filtered, dry air or N1 to blow any loose material out of the insert.
CFinally, the glass surface should be deactivated using any recommended procedure.
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