I am having calibration issues for AAS 55B for analysing Au. 242.8 nm is used.
The standards are: Au only 1,2,4,10 and 20 ppm in 10% HCl and 5% HNO3.
We have two AAS instrument. For AAS - 1, 10 ppm is consistently lower than what used to be, absorbance is 0.380-0.390. We use the same set of the standards and read on the other AAS (2), 10 ppm was read 5-7% higher than the 1st AAS instrument, absorbance is 0.405-0.415 , but the rest of the standards have got similar reading.
Could some one help me?