I have taken around 100 mg of sample for digestion and final volume was 50 ml. But the acid concentration was too high in the sample so I had to dilute it again. I have taken 1 ml from the 50 ml solution and diluted it again to 50 ml. What will be my final dilution factor?
Hi! The spectrometer gives you the result of measuring the concentration of a given element in a given sample solution. This solution is the result of preparing a known mass of a weighed sample (test portion), transferred to a solution of a specific volume and optionally additionally diluted.
And you should calculate correctly and without any mistakes the concentration of the entire "sample" in the solution used for measurement on the spectrometer, as if it were a perfectly soluble substance.
In your example, a 100 mg weight goes into a 50 mL solution. So the concentration of the "sample" is 100 mg/50 mL, or 2000 mg/L.
The initial solution was diluted an additional 50 times (1 mL to 50 mL), so the concentration of the "sample" in the solution used for spectrometric measurement was 2000/50 times lower, i.e. 40 mg/L.
And now, if the result of measuring the concentration of a given element is, for example, 10 microgram/L, i.e. 0.01 mg/L, then the content of a given element in a given sample is 0.01 mg in 40 mg, i.e. 0.01/40, i.e. 0 .00025, or 0.025%.
Calculate the concentration of "samples" in the solutions subjected to spectrometric measurements, instead of calculating any multipliers, because your analyzes concern the content of elements in the samples, which are initially in the solid state, not in the solution state. This method of conversion protects against mistakes that could occur when calculating multipliers.
ZJ
To calculate the final dilution factor, multiply the dilution factors at each step:
Initial dilution:
100 mg sample diluted to 50 mL
Dilution factor = 50 mL / 0.1 mL = 500
Second dilution:
1 mL of 50 mL solution diluted to 50 mL
Dilution factor = 50 mL / 1 mL = 50
Final dilution factor = 500 * 50x = 25,000
So the final dilution factor is 25,000 after diluting 100 mg of sample to 50 mL and then taking 1 mL of that and diluting it again to 50 mL.
The formula to calculate the dilution factor for ICP-MS analysis is:
DF = Vf / Vs
Where:
DF is the dilution factor
Vf is the final volume after dilution
Vs is the initial sample volume or weight
For example, if 100 mg of sample is diluted to 50 mL, the dilution factor would be:
DF = 50 mL / 0.1 mL = 500
If that 50 mL solution is then further diluted by taking 1 mL and diluting it to 50 mL, the overall dilution factor would be:
DF = (50 mL / 1 mL) . (50 mL / 0.1 mL) = 50 * 500 = 25,000
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