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COSMOSIL Direct Cartridge Holder

COSMOSIL Guard Cartridge Holder

COSMOSIL Column Prefilter

Spare Filter for Prefilter

COSMOSIL Column 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

Problem	Solution
Good peak separations but retention time is too long or too short.	Too long: increase organic solvent concentration by 10%. Too short: decrease organic solvent concentration by 10%.
Good retention time, but peaks are not sharply separated.	Use ion pair with longer alkyl chain, or the same ion pair using double the concentration.
No difference in separation when using ion pair, or no change occurs when trying the above solution.	For basic compounds, decrease pH. For acidic compounds, increase pH.
Retention time of the sample compound is too long.	Use ion pair of shorter alkyl chain or same ion pair of half concentration.

Ordering information

for Basic samples

Product Name	Grade	Storage	Product No.	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 No.	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) RT: Room temperature, A: Cool and dark, R: Refrigerator, F: Freeze

Ordering information

Product Name	Grade	Storage	Product No.	PKG size
Dansyl Chloride	SP	RT	10427-91	1 g
p-Bromophenacyl Bromide (PBPB)	GR	R	05802-92	25 g
3,5-Dinitrobenzoyl Chloride (DNBC)	SP	A	13530-44	5 g
N-(9-Acridinyl)maleimide (NAM)	SP	R	00842-64	50 mg
NBD Chloride	SP	R	24113-61	1 g
o-Phthalaldehyde (OPA)	SP	R	27824-61	1 g
			27824-74	5 g
			27824-32	25 g

(Storage) RT: Room temperature, A: Cool and dark, R: Refrigerator, F: Freeze

L-FDVDA (1-Fluoro-2,4-dinitrophenyl-5-L-valine-N,N-dimethylethylenediamine-amide)

This product is a red to red-yellow crystal or powder that dissolves in acetone. It is a labeling reagent for amino groups and includes a chiral carbon, enabling the separation of labeled amino acids with a C₁₈ or other achiral column (fig. 1). As the reagent itself is more easily ionizable compared to conventional products, higher sensitivity with LC-MS can be achieved (fig. 2), and it is suitable for analyzing trace amounts of peptides.

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Fig. 1: Chiral separations of L-FDVDA-labeled amino acids

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Fig. 2: Comparison of detection sensitivity using LC-MS

Data provided by Dr. Takefumi Kuranaga, Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University

References

1. Kuranaga, T.; Minote, M.; Morimoto, R.; Pan, C.; Ogawa, H.; Kakeya, H. ACS Chem. Biol. 2020, 15, p. 2499.
2. Pan, C.; Kuranaga, T.; Cao, X.; Suzuki, T.; Dohmae, N.; Shinzato, N.; Onaka, H.; Kakeya H. J. Org. Chem. 2021, 86, p. 1843.
3. Morimoto, R.; Matsumoto, T.; Minote, M.; Yanagisawa, M.; Yamada, R.; Kuranaga, T.; Kakeya, H. Chem. Pharm. Bull. 2021, 69, p. 265
4. Jiang, Y.; Matsumoto, T.; Kuranaga, T.; Lu, S.; Wang, W.; Onaka, H.; Kakeya, H. J. Antibiot. 2021, 74, p. 307.
5. Pan, C.; Kuranaga, T.; Kakeya, H. J. Nat. Med. 2021, 75, p. 339.

Ordering information

Product Name	Grade	Storage	Product No.	PKG size
1-Fluoro-2,4-dinitrophenyl-5-L-valine-N,N-dimethylethylenediamine-amide	SP	R	20363-24	50 mg

(Storage) RT: Room temperature, A: Cool and dark, R: Refrigerator, F: Freeze

Kyoto University has applied for a patent for this product, and Nacalai Tesque manufactures and sells it under license.