Brief instructions on maintaining your Metrohm ion chromatograph

This leaflet describes the basic conditions for troublefree operation of your Metrohm ion chromatograph. The most important maintenance steps are listed in the form of a guide, which answers the following questions:

• What components need to be maintained?

• What maintenance steps are required for this?

• How often should maintenance be carried out?

A detailed description of maintenance can be found in the instrument manual, where the various steps are explained in detail and illustrated with detailed drawings.



General

• Short capillaries equate to a small dead volume

• Eluent flow after high pressure pump: only PEEK capillaries with an inner diameter of 0.25 mm should be used

•	Use	ultrapure	water	(resistance	>	18.2	MΩ*	cm	25	°C)	and	p.a.	chemicals	to prepare reagents

•	Filter	samples	(0.45	μm)

• Ensure samples are fed in without any air bubbles

•	If	the	system	is	not	used	(>	2	weeks),	the	column	should	be	removed	and	the system rinsed with 20% methanol

Eluent

• Should be free of particles, algae and bacteria

• Degassing; no air bubbles in the aspiration tube and eluent

• The aspiration filter should be exchanged every 3 months or when it becomes yellow

• When changing the eluent, measures must be taken to prevent precipitations IC pump

•		Carry	out	maintenance	on	pistons,	seals	and	check	valves	at	least	once	a	year Inline filters

• Should be replaced every 3 months or when there is a high backpressure and/or when	exchanging	the	eluent.	Check	eluent	flow	twice	a	year.

Pulsation absorber

• A faulty pulsation absorber can cause long, flat waves in the baseline and must then be replaced

Injection valve

• If there are problems with precision, check the installation of the sample loop

•	Open	and	clean	a	valve	if	it	is	blocked	by	particles	(service	technician) Separation column

•		Comply	with	flow	direction

• Use precolumn and replace it regularly. Typically 3-4 precolumns are recommended per lifetime of an analytical column.

• To increase column lifetime: check the quality of chemicals, ultrapure water and use	sample	preparation	(e.g.,	Inline	Dialysis)



Suppressor

• PTFE capillaries are very soft; pressure screws should not be overtightened; shorten crushed capillaries with the help of a capillary cutter

• Do not switch the suppressor rotor in the dry state

• If the conductivity is too high, check the flow of the regenerant and rinsing solution CO suppressor

2

•		CO 	adsorber	cartrige	CW	must	be	used 2

•	CO adsorber material must be replaced when the indicator colors the adsorption 2

material	violet	(3/4	of	the	cartridge),	however	at	least	once	a	year IC conductivity detector

• In the event of any blockage ➔ shorten the inlet capillary by a few millimeters; back-flush with the help of the high pressure pump; take care: pressure must be < 5 MPa Dual-channel peristaltic pump

•		Pump	tubing	should	be	replaced	regularly	−	at	least	every	2	months

•	Contact	pressure	level	should	not	be	too	high:	increase	contact	pressure	step	by	step until flow is visible, then increase contact pressure by a further 2 ratchet increments

• Use long-life pump tubing: 6.1826.3X0 or 6.1826.420

• Use inline filters and replace them every 3 months or when there is a high backpressure Backpressure without column

with 1 mL/min flow rate:

Nonsuppressed	IC	system:		 <	1.0	MPa IC	system	with

chemical suppression:

< 1.5 MPa

IC	system	with

sequential suppression:

< 2.5 MPa

www.metrohm.com



Herisau

CH-9100

AG,

Metrohm

by

Switzerland	in

printed

ASW,

8

2015-0

change

Ecknauer+Schoch

EN –

by

135

Subject to

Layout

8.000.5