Question

Calculate the volumes of stock solution and diluent required to produce the following working standards, given that the total volume of each working standards is 3.2mL and the stock solution has a concentration of 16mmol/L Tube number Volume of stock solution (mL) Volume of diluent (mL) Concentration of working standard (mmol/L) Total volume 3.2mL 3.2mL 3.2mL 3.2mL 3.2mL 3.2mL 3.2mL 3.2mL 3.2mL

Please only calculate for Tube #1.

Answer 1

Calculation for the volume of stock required for each working standard can be done using this model-

Volume of diluent (mL)= (Concentration of working standard (mmol/L) x Total volume (mL))/ Concentration of stock solution

Tube number	Volume of stock solution (mL)	Volume of diluent (mL)	Concentration of working standard (mmol/L)	Total volume
1	0	3.2	0	3.2 mL
2	0.4	2.8	2	3.2 mL
3	0.8	2.4	4	3.2 mL
4	1.2	2	6	3.2 mL
5	1.6	1.6	8	3.2 mL
6	2	1.2	10	3.2 mL
7	2.4	0.8	12	3.2 mL
8	2.8	0.4	14	3.2 mL
9	3.2	0	16	3.2 mL