Question

In Atomic Absorption Spectrophotometry (AAS) Lab, we ask to make a standard to determine the linear range of the Mg calibration.
"First make up a 100.0 ppm Mg solution. Then from the 100 ppm solution make up 25 mLs of 0.5, 1, 2, 5, 10 and 20 ppm Mg standards, then dilute it in a volumetric flask that contain 5 mL of 2% HNO3 solution and the rest with DW"
I have to use a micropipette (uL) to prepare the standard. How do I prepare the standards of ppm using (uL) micropipette??

Answer 1

we have 100 ppm Mg solution.

from above standared solution we have to prepare 0.5,1,2,5,10 and 20 ppm in 25 ml volumetric flask.

1) 0.5 ppm solution :

C1V1 = C2V2 , FROM dilution principle,

100xX = 0.5X25

X = 12.5 /100 = 0.125 ml of above standared soltion take it in flask and make up with HNO3 and D.W

2)

1 ppm solution :

C1V1 = C2V2 , FROM dilution principle,

100xX = 1X25

X = 25/100 = 0.25 ml of above standared soltion take it in flask and make up with HNO3 and D.W

3)

2 ppm solution :

C1V1 = C2V2 , FROM dilution principle,

100xX = 2X25

X = 50 /100 = 0.5 ml of above standared soltion take it in flask and make up with HNO3 and D.W

4)

5 ppm solution :

C1V1 = C2V2 , FROM dilution principle,

100xX = 5X25

X = 125 /100 = 1.25 ml of above standared soltion take it in flask and make up with HNO3 and D.W

5)

10 ppm solution :

C1V1 = C2V2 , FROM dilution principle,

100xX = 10X25

X = 250 /100 = 2.5 ml of above standared soltion take it in flask and make up with HNO3 and D.W

6)

20 ppm solution :

C1V1 = C2V2 , FROM dilution principle,

100xX = 20X25

X = 500 /100 = 5 ml of above standared soltion take it in flask and make up with HNO3 and D.W