• Cartridge holder, prefilter and connecting tube
  • Ion pair reagents
  • Labeling reagents

Cartridge holder, prefilter and connecting tube

>> For UHPLC (COSMOCORE) fittings and adapters, please see this page.

COSMOSIL Direct Cartridge Holder

direct cartridge holder

The Direct Cartridge Holder can be used instead of our older Guard Cartridge Holder. As it screws directly into the column, no connecting tube is required for connection to analytical column.

All guard cartridges are compatible with both the Direct Cartridge Holder and the older Guard Cartridge Holder, as long as the I.D. is the same.

I.D. Product No. PKG size
4.6 mm 19989-71 1 PKG

COSMOSIL Guard Cartridge Holder

guard cartridge holder

A Guard Cartridge Holder (or the above Direct Cartridge Holder) is required to use guard cartridges.

I.D. Product No. PKG size
2.0 mm 11884-71 1 PKG

COSMOSIL Column Prefilter


COSMOSIL Column Prefilter uses smaller pores (1 µm) than the column frit (2 µm).

Product No. PKG size
39361-19 1 PKG

Spare Filter for Prefilter

spare filter
Product No. PKG size
39539-09 2 PKG

COSMOSIL Column Connecting Tube

connecting tube

For connecting COSMOSIL columns.

I.D. Product No. PKG size
0.1 mm 12570-41 1 PKG
0.25 mm 37843-69 1 PKG

Ion pair reagents

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

ion pair flow chart

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

Labeling reagents

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

Labeling reagent for chiral separation of amino acids

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

L-FDVDA structure

L-FDVDA reaction

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.

chiral separations of L-FDVDA-labeled amino acids

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

comparison of detection sensitivity with LC-MS

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


  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.