Potassium Hexacyanoferrate III — Ethylenediamine Reagent

Dipping solution Mix 20 ml methanol and 5 ml ethylenediamine and then add 5 ml of a solution of 0.5 g potassium hexacyanoferrate(III) in 100 ml water. 

On oxidation by potassium hexacyanoferrate(III) adrenaline is converted into adrenochrome which then condenses with ethylenediamine  

The chromatograms are dried thoroughly in a stream of warm air, immersed in the reagent solution for 1 s, dried in the air and heated in the drying cupboard at 65 C for 30 min. 

Fluorescent zones, which are suitable for quantitation [2], are visible in long-wavelength UV light (2 400 nm). 

Note The dipping solution may also be used as a spray solution [2]. Catecholamines are only separable on silica gel layers as their triacetyl derivatives but they can be separated underivatized on cellulose layers [4]. 

---