B DETERMINATION OF POTASSIUM BY ICP-OES

1 Solutions with potassium compounds are nebulised into an argon plasma, where all components are vaporised. Potassium compounds are dissociated and excited, and then emit radiation of which the intensity is measured at a wavelength of 766.491 nm. 

1 This procedure yields a standard cun/e that is linear up to at least 20 mg/L K. 

2 The detection limit is approximately 0.05 mg/L in the digest. The determination limit is approximately 0.14 mg/L (0.4 respectively 1.2 mmol/kg in the dried plant material). 

1 The reproducibility of determinations by this procedure should give, at reasonable control and thorough sample preparation, a coefficient of variation within 5 %. 

1 Inductively coupled plasma optical emission spectrometer. 

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