Flame-emission spectrophotometry FES

In flame-emission spectrophotometry, also frequently referred to for short as flame photometry , the sample under investigation is converted to atomic vapour by applying thermal energy (a flame). As energy continues to 

Following this period, the excited atoms, in which the outer electrons had 

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Sodium may be determined by atomic absorption spectrophotometry (AAS), flame emission spectrophotometry (FES), electrochemically with an Na -ISE, or spectrophoto-metrically. Of these methods, ISE methods are by far the most common. Excellent accuracy and coefficients of variation of less than 1.5% are readily achieved with modern equipment, reliable calibrators, and a good quality assurance program. Because sodium and potassium are routinely assayed together, methods for their analysis are described together later in this chapter. 

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