For the disassembly of Shimadzu HPLC injection needles for pre-maintenance cleaning or faulty part replacement, here are the general guidelines (specific steps should refer to Shimadzu's official operation manual):

1. Pre-cleaning flush: First, flush the injection needle with ultrapure water to remove water-soluble impurities, then use a small amount of methanol or isopropanol to rinse to avoid water residue and potential rusting.
2. Inspection: Check the needle for visible contaminants, whether the plunger slides smoothly, and for sample accumulation or tip wear.
3. Replacement consideration: If the needle cannot be effectively cleaned, the plunger is difficult to slide, or there is obvious wear/damage, replace the needle according to the manufacturer's recommendations.

If you need professional assistance with injection needle disassembly, cleaning, replacement, or overall HPLC maintenance and repair, Jiangxi Bio provides comprehensive solutions including instrument repair, maintenance, lease, and supply of parts/consumables for brands like Thermofisher, Waters, Agilent, and others (covering Shimadzu HPLC-related needs). Our services also include chromatography application consulting to support your experimental work.