why does Zinc 66 have very high count reading in the blank

Zinc is a very common lab contaminant - trace amounts are in gloves, vials, pipette tips, peripump tubing, Kim wipes etc so clean prep and materials become essential.

For low level zinc analysis a good starting point is to prewash all sample vials. I like to fill any prep vials with 1-2% HNO3, let them sit for a day or two, rinse well and fill with DI water and then cap. When ready to use empty the water and use.

Make sure your pipette tips are specific to trace metals analysis. You can also prewash pipette tips too if you find just doing the vials isn’t enough. 

Also make sure you are using ultra trace acid.

Zinc is a very common lab contaminant - trace amounts are in gloves, vials, pipette tips, peripump tubing, Kim wipes etc so clean prep and materials become essential.

For low level zinc analysis a good starting point is to prewash all sample vials. I like to fill any prep vials with 1-2% HNO3, let them sit for a day or two, rinse well and fill with DI water and then cap. When ready to use empty the water and use.

Make sure your pipette tips are specific to trace metals analysis. You can also prewash pipette tips too if you find just doing the vials isn’t enough. 

Also make sure you are using ultra trace acid.

Hi Cheltajc, 

Thank you for telling us this information. They are quite helpful. I will do this before proceeding the next step. 

Best regards, 

Di Xu