Question

Could someone please help me figure out how to do the bottom portion of this question? (% transmittance)

You measure the %T values for a series of Six BUN Standard solutions. You need to convert the values to absorbance to determine its relationship to the solution concentration. You process your patient's BUN sample and determine its % Transmittance to be 38.5. What is the concentration of BUN in your patient's sample? Is this reading high, low or normal? high low normal

Answer 1

For the botton part of the question do the following:

• First convert transmittance 38.5 to absorbance.The formula is A = 2- log₁₀ %T
• Substituting the value of transmittance , we get absorbance value as 0.4145
• Plot a graph for the standard solution 1 to 6 taking concentration of BUN [BUN] (M) in x axis and absorbance in Y axis.Take in an increasing order of [BUN] (M) (from sample 6 to 1)
• This will give you a standard curve.
• From this curve ,corresponding to 0.4145 absorbance , find out the concentration of BUN.This will give you the patient BUN concentration.
• The normal BUN value should be 1.8 to 7.1 mmol / litre.
• Convert the patient's BUN in M (moles/litre) to mmol/litre and then compare with the normal value to find out if the reading is high , low or normal.

1.2 0.8 Absorbance 0.6 0.41 patient absorbance 0.4 0.2 patient [BUN Concentration of BUN (in M)