Monovalent and Divalent Cation Standards (3) (Dipicolinic Acid + Crown Ether Eluent)

The problems in the anaysis using IC YK-421 is that the analysis of very small amount of NH₄⁺ in a sample which contains large amount of Na⁺ is difficult. Addition of 1.5mM 18-Crown 6-ether in 5mM Tartaric acid + 1mM Dipicolinic acid + 1.5g/L Boric acid eluent can solve the problem. Addition of crown 6-ether can adjust the elution volume of the cations. Especially, the elution volume of K⁺ is largely affected by the additon and elute after Mg²⁺.

Sample :
1. Li⁺
2. Na⁺
3. NH₄⁺
4. Ca²⁺
5. Mg²⁺
6. K⁺

 Column : Shodex IC YK-421 (4.6mmID*125mm)
 Eluent : 5mM Tartaric acid + 1mM Dipicolinic acid
 + 1.5g/L Boric acid + 1.5mM 18-Crown 6-ether aq.
 Flow rate : 1.0mL/min
 Detector : Shodex CD
 Column temp. : 40°C