A DETERMINATION OF SODIUM BY FLAME AES

1 The sample is vaporised in an air-propane flame and the sodium compounds are atomised. The sodium atoms thus formed emit radiation of which the intensity is measured at a wavelength of 589.0 nm. 

1 This procedure yields a standard curve that is linear up to approximately 15 mgfl Na. 

2 The detection limit is approximately 1.0 mg/L in the digest The determination limit is approximately 3.0 mg/L (6.0-21 mmol/kg in the dried plant material). 

1 To prevent ionisation interferences, cesium is added to act as an ionisation buffer. 

1 The reproducibility of determinations by this procedure should give, at reasonable control and thorough sample preparation, a coefficient of variation within 10 %. 

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