Imagine that your initial absorbable reading for “low salt” fraction was too high, so you diluted your sample 4 times. When you measure the absorbable using 100 ul of the diluted sample , the absorbance is 0.6. What is the concentration of the original undiluted sample (mg/ml)
To find the concentration of the original undiluted sample, you can use the dilution formula:
C1V1 = C2V2
where:
C1 = concentration of the original undiluted sample
V1 = volume of the original undiluted sample used for dilution
C2 = concentration of the diluted sample
V2 = volume of the diluted sample
In this case, the dilution factor is 4, meaning the diluted sample is 4 times less concentrated than the original sample.
Given:
C2 = 0.6 (absorbance)
V2 = 100 ul (volume of the diluted sample)
Dilution factor = 4
Now, let's calculate the concentration of the original undiluted sample (C1):
C1 * V1 = C2 * V2
C1 * V1 = 0.6 * 100
Since the dilution factor is 4, the volume of the original undiluted sample used for dilution (V1) can be calculated by dividing the volume of the diluted sample (V2) by the dilution factor:
V1 = V2 / Dilution factor
V1 = 100 / 4
V1 = 25 ul
Now, substitute the values back into the equation:
C1 * 25 = 0.6 * 100
C1 * 25 = 60
C1 = 60 / 25
C1 ≈ 2.4 mg/ml
Therefore, the concentration of the original undiluted sample is approximately 2.4 mg/ml.
To determine the concentration of the original undiluted sample, we can use the dilution formula:
C1V1 = C2V2
Where:
C1 = concentration of the original undiluted sample
V1 = volume of the original undiluted sample
C2 = concentration of the diluted sample
V2 = volume of the diluted sample
We know that the diluted sample was diluted 4 times, so C2 = C1/4 and V2 = 100 ul.
Plugging in the values:
C1 * V1 = (C1/4) * 100 ul
Simplifying the equation:
V1 = (C1/4) * 100 ul / C1
Simplifying further:
V1 = 25 ul
Now, we need to determine the concentration (C1) of the original undiluted sample. We know that the absorbance of the diluted sample (A2) is 0.6.
The relationship between absorbance, concentration, and path length is given by Beer's Law:
A = ε * c * l
Where:
A = absorbance
ε = molar absorptivity (a constant for a given substance)
c = concentration
l = path length (typically 1 cm)
Assuming that the path length is 1 cm, we can rearrange the equation to solve for concentration:
c = A / (ε * l)
Let's assume ε and l are both constants.
Therefore, c2 = A2 / c1
Multiplying both sides by c1:
c1 * c2 = A2
Substituting the values:
c1 * 0.6 = A2
Now, we can solve for c1 (the concentration of the original undiluted sample):
c1 = A2 / 0.6
Substituting the given absorbance value:
c1 = 0.6 / 0.6 = 1
Therefore, the concentration of the original undiluted sample is 1 mg/ml.
To determine the concentration of the original undiluted sample, you can use the dilution equation. The equation states that the initial concentration multiplied by the initial volume is equal to the final concentration multiplied by the final volume.
Given that you initially diluted the sample by a factor of 4, this means that the final volume is 4 times greater than the initial volume. You used 100 µl of the diluted sample for measurement, so the final volume is 4 times that, which is 400 µl.
Let's assume the concentration of the undiluted sample is C. Using the dilution equation, we can write:
C (initial concentration) * V1 (initial volume) = Cf (final concentration) * Vf (final volume)
Since the final volume is 400 µl and the absorbance is 0.6, we can rewrite the equation as:
C * V1 = 0.6 * 400 µl
Now, you need to rearrange the equation to solve for C (initial concentration):
C = (0.6 * 400 µl) / V1
However, we need to convert µl to ml for the units to match. There are 1000 µl in 1 ml, so the equation becomes:
C = (0.6 * 0.4 ml) / V1
Now, we know that the sample was diluted 4 times, so V1 (initial volume) is equal to 100 µl (the volume of the diluted sample) multiplied by 4:
V1 = 100 µl * 4 = 400 µl
Substituting this value into the equation, we get:
C = (0.6 * 0.4 ml) / 400 µl
Now, we can simplify the equation:
C = 0.24 ml / 400 µl
To convert ml to mg, you need to know the density or molecular weight of the solute. Without that information, it is not possible to determine the concentration in mg/ml based on the provided data.