General Information on Packed Columns = Column Cleaning Procedure

Column Cleaning Procedure

When a column is deteriorated by the foreign substances remaining in the column or adsorbed by the packing material, the substances might be washed out by the procedure described below. However, sometimes the procedure is not suffcient to regenarate the column and, in such case, it is necessary to replace the column with a new one. And, even if the column can be regenarated, the column performance may be not so good as before. After cleaning the column, be sure to replace the in-column solvent to the normal solvent. The use of a guard column at the up-stream of the main column is recommended to prevent the main column from the deterioration by the foreign substances. When a guard column is used, first, the guard column will be deteriorated by the foreign substances and it is possible to prevent the main column from the deterioration by replacing the guard column regularly.
When cleaning a guard column, be sure to disconnect the main column before the cleaning. If a guard column and a main column are connected in series and the cleaning procedure is performed, foreign substances in the guard column may move to the main column and, as the consequence, the main column may be deteriorated.

Category	Column name		Coulmn cleaning procedure
Normal & Reversed Phase (Polymer- based)	Asahipak	NH2P	Reverse the column on chromatograph and flow 5mL of H₂O, 60mL of 0.1M HClO₄ aq., 5mL of H₂O, 60mL of 0.1M NaOH aqueous solution and then 5mL of H₂O at the flow rate of 0.5mL/min.
	Asahipak	ODP C8P, C4P	Flow 50mL of dioxiane, CH₃CN or methanol.
	RSpak	RP18, DS
	RSpak	DE, GOLF CARB
	RSpak	DM	Flow 50mL of methanol, CH₃CN or H₂O.
	RSpak	DC	Flow 50mL of CH₃CN, or 5mM NaOH aqueous solution. Or, inject 20 to 50 micro-L of 0.5M NaOH aqueous solution.
	RSpak	NN	Inject 20 to 50 micro-L of 2N nitric acid aqueous solution two or three times.
Normal & Reversed Phase (Silica- based)	ODSpak	F	Flow 50mL of dioxiane, THF, CH₃CN or methanol.
	Silica	C18M, C18P	Flow 50mL of dioxiane, THF, CH₃CN or methanol.
	Silicapak	E	Flow 50mL each of n-hexane, dichloroehtane, methanol, dichloroethane and n-hexane.
	SIlica	5SIL
	Silica	5C8, 5C4 5TMS, 5CN	Flow 50mL of dioxane, CH₃CN or methanol.
	Silica	5NH	There is no appropriate washing method.
	Silica	5NPE
	Silica	5PYE
Ion excahnge	AXpak	WA	Inject 1 to 2 mL of 0.1M NaOH aqueous solution or 30% acetic acid aqueous solution. Connect the column in the reverse way and flow the eluent at 0.5mL/min.
	CXpak	P
	IEC	QA, DEAE SP, CM
	IEC	DEAE-420N SP-420N	Inject 500 micro-L of 0.1M NaOH aqueous solution, 50% formic acid aqueous solution, 20% CH₃CN aqueous solution or 20% dimethyl sulfoxide aqueous solution several times. Flow the eluent at 0.3 to 0.5mL/min.
	Asahipak	ES-502N	Flow aqueous solution of high salt concentartion or 10mM NaOH aqueous solution for ionic adsorption and 50mM buffer solution containing 50% CH₃CN or methanol for hydrophobic adsorption.
	Asahipak	ES-502C	Flow aqueous solution of high salt concentartion or 0.1N acetic acid aqueous solution for ionic adsorption and 50mM buffer solution containing 50% CH₃CN aqueous solution or methanol for hydrophobic adsorption.
Hydrophobic chromato graphy	HIC	PH	Reverse the column on the HPLC system, flow the eluent at 0.5mL/min and inject 1 to 2 mL of 0.1M NaOH or 30% acetic acid aqueous solution several times.
Affinity chromato graphy	AFpak	31 kinds	Reverse the column on the HPLC system, flow an appropriate eluent at 0.5mL/min.
Sugar analysis	SUGAR	SH	Flow 50mL of 25mM H₂SO₄ aqueous solution at 50deg-C, 0.5mL/min.
	SUGAR	SC	( for SC1011, 1821) Flow 50mL of 0.1M Ca(NO₃)₂ aqueous solution at 50deg-C, 0.5mL/min. (for SC1211) After replacing in-column solvent completely with H₂O, flow 30mL of 0.1M Ca(NO₃)₂ aqueous solution at 50deg-C, 0.5mL/min. Then, replace the in-column solvent completely with H₂O and gradually increase the organic solvent concentration to the concentration to be used.
	SUGAR	SP	Flow 50mL of 0.2M Pb(NO₃)₂ at 50deg-C, 0.5mL/min.
	SUGAR	SZ	After replacing in-column solvent completely with H₂O, flow 30mL of 0.1M Zn(NO₃)₂ aqueous solution at 50deg-C, 0.5mL/min. Then, replace the in-column solvent completely with H₂O and gradually increase the organic solvent concentration to the concentration to be used.
	SUGAR	KS	Flow 10mM NaOH aqueous solution at 0.5mL/min. After flowing the solvent, replace the in-column solvent completely with H₂O. (Sometimes, injection of 40micro-L of 0.1M NaOH aqueous solution is will be sufficient.)
	USPpak	MN	Flow 50mL of 0.1M Ca(NO₃)₂ aqueous solution at 50deg-C, 0.5mL/min.
Organic acid analysis	RSpak	KC	flow 50mL of 25mM H₂SO₄ aqueous solution at 50deg-C, 0.5mL/min.
Chiral separation	ORpak	CDA, CDB CDC	There is no appropreate cleaning method.
Chiral separation	ORpak	CDBS, CRX	There is no appropreate cleaning method.
GFC (aqueous GPC)	OHpak	SB	Reverse the column on the HPLC system, flow the eluent at 80% of ordinary flow rate. This is effective for the foreign substances remaining in the column, however not effective for the substances adsorbed to the packing material.
	PROTEIN	KW-800
		KW400-4F
Multimode	Asahipak	GS
Multisolvent GPC	Asahipak	GF
Organic GPC	GPC	KF, K, KD, LF HFIP, HT UT, AT
Ion chromato graphy	IC	I-524A	--Pollution by accumulation of metals-- 30minutes: 0.01M tartaric acid (pH3 to 4, adjust with 0.1M NaOH), 1.0mL/min --Pollution by proteins-- 150 minutes: 20% acetic acid aq., 0.2mL/min 150 minutes: water, 0.2mL/min --Pollution by organics-- 150 minutes: 20% acetonitrile/water, 0.2mL/min 150 minutes: water, 0.2mL/min
	IC	NI-424	Flow the mixture of eluent/methanol=90/10 at 0.6mL/min for two hours.
	IC	SI-90	--Pollution by low valency hydrophilic ions-- 1. 15 minutes: deionized water 2. 60 minutes: 10 times concentrated eluent 3. 15 minutes: deionized water 4. 60 minutes: eluent --Pollution by high valency hydrophobic ions-- 1. 15 minutes : deionized water 2. 10 minutes: 5% acetonitrile aqueous solution 3. 60 minutes: 100% acetonitrile 4. 30 minutes: deionized water 5. 60 minutes: eluent
	IC	SI-50	--Pollution by low valency hydrophilic ions-- (flow rate 0.3mL/min) 1. 25 minutes : deionized water 2. 100 minutes : 10 times concentrated eluent 3. 25 minutes : deionized water 4. 100 minutes : eluent --Pollution by high valency hydrophobic ions-- (flow rate 0.3mL/min) 1. 25 minutes : deionized water 2. 20 minutes : 5% acetonitrile aqueous solution 3. 100 minutes : 100% acetonitrile 4. 50 minutes : deionized water 5. 100 minutes : eluent
	IC	T	Flow 1M NaOH aqueous solution at 0.5mL/min for two hours.
	IC	R	Flow 1M NaOH aqueous solution at 0.5mL/min for two hours.
	IC	Y	Inject 100micro-L of 1M HNO₃ aqueous solution several times.
	IC	YK	Flow 50mL of 50mM tartaric acid aqueous solution or 50mM tartaric acid aqueous solution/CH₃CN=50/50 at 0.3mL/min.
LC/MS, rapid analysis of medicines	Asahipak	ODP	Flow 50mL of dioxane, CH₃CN or ethanol.
	MSpak	GF, GS	Reverse the column on the HPLC system, flow the eluent at 80% of ordinary flow rate. This is effective for the foreign substances remaining in the column, however not effective for the substances adsorbed to the packing material.
	MSpak	SP	Flow the eluent at 0.3 to 0.5mL/min and inject 500micro-L of 0.1M NaOH aqueous solution, 50% formic acid aqueous solution, 20% CH₃CN aqueous solution or 20% dimethylsulfoxide aqueous solution several times.
GPC clean-up	CLNpak	EV	Reverse the column on the HPLC system, flow the eluent at 80% of ordinary flow rate. This is effective for the foreign substances remaining in the column, however not effective for the substances adsorbed to the packing material.
GPC clean-up	CLNpak	PAE