Need help with IH calculations
I'm in an advanced IH class and I am having difficulties with understanding all the formula numbers for figuring out minimum sampling times does anyone have an easy cheat sheet or excel template?
Comments (13)
There's no one answer to that question as it'll depend on the method, limit of quantification, and concentration in the air.
Can you give an example of the question you're trying to answer?
-Manganese Fumes NIOSH 7302 5 mg/m3 (OSHA Ceiling)
1. Which sampling media will you be using?
2. What flow rate will you use?
3. Calculate the minimum sampling time you will require to be able to detect concentrations at the OELs listed in the table. Show your work in calculating the sampling times.
4. Will you collect personal or area samples? Explain why.
5. Are there any compounds listed in the method that might interfere with your sample?
My answers so far.
1. I will be using a mixed cellulose ester membrane (MCE) filter at 37-mm diameter, 0.8-µm pore size) sampling media with a flow rate of 1 to 4 L/min
2. 1-4 L/min
3. 5x54.98=274.9/24.45=11.24
X=11.24
Limit of detection=.09/1000=.00009
11.24/.00009=.00101 *1000=1.01
1.01/4=13.37min
4.Personal sampling pump, 1 to 4 L/min, with flexible connecting tubing
5.Spectral interferences are the primary interferences encountered in ICP-AES analysis. These are minimized by judicious wavelength selection, inter-element correction factors and background correction