RSpak KC-811 is an ion exclusion chromatography column for organic acid analysis. The packing material consists of styrene-divinylbenzene copolymer modified with strongly acidic sulfo groups. By using a diluted strong-acidic aqueous solution as an eluent, organic acids exist in equilibrium of dissociated and undissociated states. In ion exclusion chromatography mode, undissociated organic acids are retained by hydrophobic interaction with the packing material. Meanwhile, dissociated organic acids are retained less as they are electrostatically repelled by the functional groups. Thus, differences in pKa and polarity of organic acids make them separated from each other in the ion exclusion chromatography. Strong acids commonly used are phosphoric acid, perchloric acid and p-toluenesulfonic acid. This application introduces analyses of organic acids using 0.1 % phosphoric acid, 5-mM p-toluenesulfonic acid and 5-mM perchloric acid as an eluent. The same resolution level can be obtained under any of the eluent conditions. However, in the case of 0.1 % phosphoric acid with RI detector, quantification of citric acid may not be accurate since the system peak overlaps with its peak. On the other hand, p-toluenesulfonic acid is not a suitable eluent for organic acid analysis when used with a UV detector, as p-toluenesulfonic acid has high UV absorbance. For organic acid analysis, the post-column reaction method is another option. We recommend selecting an appropriate acidic eluent for each detection method.
Sample: 5 μL
- 1.Citric acid 1.3 %
- 2.Tartaric acid 1.3 %
- 3.Malonic acid 1.3 %
- 4.Succinic acid 2.0 %
- 5.Lactic acid 2.5 %
- 6.Formic acid 3.0 %
- 7.Acetic acid 3.0 %

- Column
- :Shodex RSpak KC-811 (8.0 mm I.D. x 300 mm)
- Eluent
- :(a) 0.1 % H3PO4 aq.
(b) 5 mM p-Toluenesulfonic acid aq.
(c) 5 mM HClO4 aq. - Flow rate
- :1.0 mL/min
- Detector
- :RI
- Column temp.
- :40 ℃
Sample Name Index
Operation Manual / Certificate of Analysis
Operation Manuals and Certificate of Analysis / Inspection Certificate for the following products can be downloaded here.
Product Name Index
Applications
- Effects of Flow Rate (KC-811)
- Effects of Injection Volume (KC-811)
- Effects of Sample Load (KC-811)
- Effects of Column Temperature (KC-811)
- Effects of Concentration of Eluent on Elution Volume (KC-811)
- Effects of Column Temperature on Elution Volume (1) (KC-811)
- Effects of Column Temperature on Elution Volume (2) (KC-811)
- Effects of Acetonitrile in Eluent (1) (KC-811)
- Effects of Acetonitrile in Eluent (2) (KC-811)
- Effects of Reversed Phase Column on Elution Volume (KC-811 + DE-613)
- Elution Volume of Aromatic Organic Acids (NN-814)
- Elution Volume of Organic Acids (NN-814)
- Elution Volume of Organic Acids (DE-413)
- Comparison of Analysis of Organic Acids with 4 Kinds of Detectors (Standards) (KC-811)
- Comparison of Analysis of Organic Acids with 4 Kinds of Detectors (Soy Sauce) (KC-811)
- Organic Acid Standards (1) (KC-811)
- Organic Acid Standards (2) (KC-811)
- Organic Acid Standards (3) (KC-811)
- Organic Acid Standards (4) (DE-413)
- Organic Acid Standards (5) (DE-213)
- Citric Acid in Phosphoric Acid (DE-613 + KC-811)
- Analysis of Organic Acids in Beer (KC-811)
- Analysis of Organic Acids and Vitamin C in Fruit Juice (KC-811)
- Reverse Phase Analysis of Gluconic Acids (DE-613)
- Analysis of Organic Acids in Sake (Japanese Rice Wine) (KC-811)
- Analysis of Organic Acids in White Wine (KC-811)
- Analysis of Oxalic Acid Using Ion Exclusion Mode (KC-811)
- Organic Acid in Phosphoric Acid (DE-613 + KC-811)
- Analysis of Organic Acids in Soy Sauces (KC-811)
- Organic Acids in Vinegar (KC-811)
- Separation of Succinic Acid and Fumaric Acid (KC-811)
- Analysis of Organic Acids (Eluent Conteinig Cyclodextrin) (KC-811)
- Camphor and Benzoic Acid (NN-814)
- Di-carboxylic Acids (DE-413)
- Analysis of Organic Acids in Soybean Paste (KC-811)
- Analysis of Organic Acids in Soy Sauce For Noodles (KC-811)
- Organic Acids Analysis in Black-vinegar (KC-811)
- LC/MS Analysis of Organic Acids (DE-213)
- Simultaneous Analysis of Saccharides, Organic Acids and Amino Acids with LC/MS (VG-50 2D)
- Simultaneous Analysis of Hydrophilic Substances in Energy Drink with LC/MS (VG-50 2D)
- Organic Acids (KC-811)
- LC/MS Analysis of Pipecolic Acid (NH2P-40 2D)
- Elution Volume of Organic Acids (NI-424)
- Analysis of Formic Acid in Povidone According to Pharmacopeia Method (KC-811)
- Analysis of Related Compounds of Alanine and Aspartic Acid According to USP-NF Method (SH1011)
- Analysis of Acetic Acid in Vinegar Drinks (KC-811)
- Citric Acid Analysis in Functional Beverage (KC-811)
- Organic Acid Determination Test for Glycerin Fatty Acid Esters According to Japan’s Specifications and Standards for Food Additives (SH1011) (SH1011)