Saturated detector - atomic absorption spectrophotometer, graphite furnace mode,

Hello Pereira,

Do you get the overrange error on your blank as well as standards? Have you checked the cookbook in the method for what concentration will give 0.2 abs at 10uL inject?  Make sure you compare the value to the wavelength you are running and it should give you an idea of how high you can go.  I recommend trying to keep your high standard to around 0.8Abs max, you start losing linearity above that.  Beer-Lambert law breaks down above 1 Abs.

Does it do this for all elements or only one?  If only one, it could be a lamp issue.

Have you checked your lamp gain in Optimize?  The burner adjuster position is much different for the flame burner and the GFAA workhead.  If the workhead is not properly aligned and you are blocking all or most of the light you Absorbance will be very high.  Below is a pdf with typical lamp gains.  These are for a flame AA with nothing blocking light, from the title of this post you have a Flame/Furnace instrument. First remove the workhead and check lamp alignment and gain.  Once optimized and you are close to or better than the typical lamp gain for your element, put the workhead back in and you should only lose about 35% of signal.  So if you stay on optimize and rescale to get the signal close to 1, then install the workhead, it should only go down to about 0.65.  Rescaling at this point will bring the signal up but also increase the gain a little.  Make note of what it is for future runs.  If this was a zeeman instrument, pull the workhead forward and optimize the lamp to give the best gain, it will be higher than those listed in the document as there is a polarizer in the beam that reduces light.  Again, when you move the workhead back into position there should only be about a 35% drop in signal.

If you use a multielement lamp make sure you are using the recommended current on the lamp label.  Default current in the methods are for single element lamps.

Let us know if this helps.