[Ketones]

I'm trying to detect the Zinc in samples. We use Zinc Sulfate to make our water soluble products. When we test the product via AA, Zinc does not show up when the sample is dissolved in water.  We know the Zinc is in the product, because if we test our sample when we add EDTA and some HCl(instead of dissolving the sample in water), the Zn is detectable. Zinc Sulfate is water soluble. So how come the AA can not detect the Zinc Sulfate when dissolved in water, but it can detect it when it's dissolved in EDTA/HCl? We do not have this issue when we use Zinc Chelate powder for water soluble products.

[Hunter2]

Add some HCl to the Probe. Not only water. ZnSO4 is difficult to vapourize.