Dear all and Rudy especially,

I have a problem in analysing Gold content reliably in a citrate bath - using an AAS and a Gold lamp at 242.8 nm - the reading variance is 10%. The basic absorbance is at the absurd level of 5 ppm and the max  absorbance is at 6 ppm. i.e basic is say 0.250 and max at 6ppm is .490. (The AAS manufacturer is not attuned to base rdg should be less or equal to lower end resolution concept) Finally the variance in reading is like 0.5 ppm. Plotting a curve after suppression etc with all these variations I am as close to +/- 15%. Gravimetric is too long. Does anyone know better - say 2- 3% accuracy??
 
Further we use a KAuCn2 as std. the corresponding readings for the complex bath - at equivalent Gold - say 1 ppm / 3 ppm etc. are lesser at 90% absorbance - ( even with 5% HCL) 

Grateful
Anil Kher

  
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