Read 3 Standard

GOOD MANUFACTURING PRACTICE (cGMP)
1

Hello. I have a doubt. I used atomic absorption.

I read 3 times 3 standard.

One of the readings in blank (for temporary instrument error)

Can I use the other reading for calculation or I have repeat all over again?

Thanks

2

It is normal to zero absorbance on the blank. You will have to have 3 standards at 3 concentrations (not just 2) since the curve is Lagrangian and not linear. Be sure your sample is in the range.

3

Ok the result of Absorbance is:

  1. 0.100

  2. 0.101

  3. 0.103
    Mean 0.102

  4. 0.202

  5. 0.001 (!)

  6. 0.203
    Mean 0.202

  7. 0.303

  8. 0.300

  9. 0.300
    Mean 0.301

It is permissible?

The result of Sample is: 0.101

4

Not really. It depends on the sample. If it is a pharmaceutical you must perform a ‘laboratory investigation report and a root cause analysis’. I presume the standard was not added to the container. Then reanalyze the sample.

For an environmental sample follow EPA procedures. (It’s been a long time for me).