Discussion Category: Atomic Absorption
Aluminum
Dear friends
I want to measure AL level in serum by graphie furnace. My calibration curve for AL standard is very good, but when i inject diluted serum into graphite, it seems that repeatablity of method is poor. For example for first injection, reported value is 55 ppb and for another injection is 88 and for another injection is 28, in the other hand, i have some major flactuation in reading value. Please help me. What can i do solve this problem.
Regards,
Hadi Parsian
Reply byCheck next:
-Are other readings of Al consistent? If not, it is probably that autosampler got misaligned or cuvette is worn.
-If not, is your sample pH close to standard's pH value? The size of the drop can vary then. (should be above pH2)
-Is your sample properly digested? Might be it stayed a bit colloid, or has precipitation, hence not homogenous.
-Is atomization temperature high enough. oxides (which do form here) are pretty sturdy so Al needs a lot of heat to ionize. That's why you use nitrous oxide in flame mode.
Best of luck.