NACALAI TESQUE, INC.

• Ion pair reagent
• Labeling reagent
• Cartridge Holder, Prefilter and Connecting tube

The use of ion pair reagents as mobile phase additives extends the applicability of reversed phase HPLC. Ionic or highly polar compounds are difficult to analyze by reversed phase using only organic solvent and buffer solution because of the short retention time. Ion pair reagents are strong hydrophobic ions which form neutral ion pairs with oppositely charged samples molecules, making the efficient ODS columns amenable to separate ionic or highly polar samples.

Nacalai offers a broad range of ion pair reagents for pharmaceutical compounds and other highly polar materials.

When using ion pair regents, ample time should be allowed for establishing equilibrium and for cleaning the column. When using ion pair regents with an alkyl chain of C₁₀ or shorter, it typically takes 20 minutes for establishing equilibrium and 30 minutes for cleaning. It may take more than 1 hour to clean the column when using ion pair reagents with an alkyl chain longer than C₁₀. Therefore, it is highly recommended to prepare a column for exclusive use with ion pair reagents.

General use of ion pair reagents in the mobile phase

Table. Retention time and separation adjustment

Troubles	Solutions
1. Good peak separations but retention time is too long or too short.	1. Too long : increase organic solvent concentration by 10%. Too short : decrease organic solvent concentration by 10%.
2. Good retention time bur peaks are not sharply separated.	2. Use ion pair of longer alkyl chain or the same ion pair but double the concentration.
3. No difference in separations between using ion pair and not using, or no change appears trying solution No.2.	3. For basic compounds analysis, decrease pH value. For acidic compounds analysis, increase pH value.
4. Retention time of the interested compound is too long.	4. Use ion pair of shorter alkyl chain or same ion pair of half concentration.

Ordering information

for Basic samples

Product name	Grade	Storage	Product number	PKG size
Sodium1-Butanesulfonate	SP	RT	31331-94	5 g
Sodium1-Butanesulfonate (0.5M solution)	SP	RT	31332-84	5 x 10 ml
Sodium1-Pentanesulfonate	SP	RT	31730-64	5 g
			31730-22	25 g
Sodium1-Hexanesulfonate	SP	RT	31529-24	5 g
			31529-82	25 g
Sodium1-Hexanesulfonate (0.5M solution)	SP	RT	31532-64	10 ml
			31532-06	5 x 10 ml
Sodium1-Heptanesulfonate	SP	RT	31528-34	5 g
			31528-92	25 g
Sodium1-Octanesulfonate	SP	RT	31729-04	5 g
			31729-62	25 g
Sodium1-Octanesulfonate (0.5M solution)	SP	RT	31733-34	10 ml
			31733-76	5 x 10 ml
Sodium1-Nonanesulfonate	SP	RT	31626-44	5 g
Sodium1-Decanesulfonate	SP	RT	31429-34	5 g
Sodium1-Undecanesulfonate	SP	RT	32030-04	5 g
Sodium1-Dodecanesulfonate	SP	RT	31426-64	5 g
Sodium Lauryl Sulfate	SP	RT	31623-32	25 g

for Acid samples

Product name	Grade	Storage	Product number	PKG size
Tetra-n-butylammonium Bromide	SP	R	32824-72	25 g
Tetra-n-butylammonium Chloride	EP	R	32935-64	5 g
			32935-22	25 g
Tetra-n-butylammonium Hydrogensulfate	GR	RT	32924-62	25 g
Tetra-n-butylammonium Iodide	SP	R	32905-54	5 g
			32905-12	25 g
Tetra-n-butylammonium Perchlorate	SP	R	32906-44	5 g
			32906-02	25 g
Tetra-n-butylammonium Phosphate	SP	R	32929-54	5 g
Tetra-n-butylammonium Phosphate (0.5M solution)	SP	RT	32926-26	10 ml
			32926-84	5 x 10 ml

(storage) A : Cool and dark, RT : Room temperature, R : Refrigerator