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# Calculating PPM

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### #1 chandch

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Posted 11 December 2012 - 10:33 AM

Hi all
I am trying to calculate 1 ppm, 100 pmm for cis-3- hexenyl acetate solution (98%). FW is 142.2 and density is 0.897. Can anybody help me how to calculate ppm.

Thank you

Edited by chandch, 11 December 2012 - 10:52 AM.

### #2 pito

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Posted 11 December 2012 - 10:35 AM

chandch, on 11 December 2012 - 10:33 AM, said:

Hi all
I am trying to calculate 1 ppm, 100 pmm for hexenyl acetate solution (98%). Can anybody help me how to calculate ppm.

Thank you
Do you know what ppm means?

and you mean 100ppm right, not 100pmm?
If you don't know it, then ask it! Better to ask and look foolish to some then not ask and stay stupid.

### #3 chandch

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Posted 11 December 2012 - 10:37 AM

Hi

### #4 pito

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Posted 11 December 2012 - 11:05 AM

chandch, on 11 December 2012 - 10:37 AM, said:

Hi

well, if you know what it means,then why cant you calculate it?

100 ppm means 100 parts per million , so 100parts of your subtance in a total of 1 million parts, meaning:
100 parts your substance + 999 900 parts solution.

I am assuming its a powder form?
Meaning it is mass in liquid.

If we use water (then 1kg=+-1l)
We can say (in general):

ppm = 1g/m3 = 1mg/L

If you thus make 1 liter you need 1mg of 100% cis-3- hexenyl acetate solution, but yours is 98%, so you would need a bit more (1,02mg).
If you don't know it, then ask it! Better to ask and look foolish to some then not ask and stay stupid.

### #5 chandch

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Posted 11 December 2012 - 11:20 AM

Hi. It's in liquid form. The FW is 142.2 and relative density is 0.897 g/cm3 which is 897 kg/m3. So do I need to take 10 µl cis-3-hexenyl acetate and 990 µl solvent to make 100 ppm

Thank you

Edited by chandch, 11 December 2012 - 11:21 AM.

### #6 bob1

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Posted 11 December 2012 - 11:25 AM

chandch, on 11 December 2012 - 11:20 AM, said:

So do I need to take 10 µl cis-3-hexenyl acetate and 990 µl solvent to make 100 ppm
No - that's 1 part per 100 (10 in 1000)... you need to add some zeros on the end of the solvent.

### #7 pito

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Posted 11 December 2012 - 11:36 AM

chandch, on 11 December 2012 - 11:20 AM, said:

Hi. It's in liquid form. The FW is 142.2 and relative density is 0.897 g/cm3 which is 897 kg/m3. So do I need to take 10 µl cis-3-hexenyl acetate and 990 µl solvent to make 100 ppm

Thank you
oh my bad, did not see that.

0.897 g/cm3
and
1 mL = 1 cm3

so 0,897grams per ml.
And you need 1,02mgrams..
So how many ml do you need?

Edited by pito, 11 December 2012 - 12:34 PM.

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### #8 chandch

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Posted 11 December 2012 - 11:49 AM

Is it 1.13 ml? But How can I calculate 10 and 100 ppm from my original liquid,. Could you please explain.

Thank you

Edited by chandch, 11 December 2012 - 11:50 AM.

### #9 pito

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Posted 11 December 2012 - 12:01 PM

chandch, on 11 December 2012 - 11:49 AM, said:

Is it 1.13 ml? But How can I calculate 10 and 100 ppm from my original liquid,. Could you please explain.

Thank you

?
Well I just explained how to calculate the 100ppm
see:
If we use water (then 1kg=+-1l)
We can say (in general):

ppm = 1g/m3 = 1mg/L

If you thus make 1 liter you need 1mg of 100% cis-3- hexenyl acetate solution, but yours is 98%, so you would need a bit more (1,02mg).

and the previous post.

So if you know how to make 100ppm, you should be able to make 10ppm too..
If you don't know it, then ask it! Better to ask and look foolish to some then not ask and stay stupid.

### #10 chandch

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Posted 11 December 2012 - 12:12 PM

For example, so my liquid is 0.897 g/cm3 is 0.897 g/ml. So I need 100 ppm. If I take 1.02 ml and put in 998.98 ml solvent which is 100 ppm. Am I right? or If I take 0.51 ml and 499.49 ml solvent, so it is 100 ppm. am I right?

### #11 pito

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Posted 11 December 2012 - 12:39 PM

chandch, on 11 December 2012 - 12:12 PM, said:

For example, so my liquid is 0.897 g/cm3 is 0.897 g/ml. So I need 100 ppm. If I take 1.02 ml and put in 998.98 ml solvent which is 100 ppm. Am I right? or If I take 0.51 ml and 499.49 ml solvent, so it is 100 ppm. am I right?

If you take 1,02ml, you have= 1,02ml x 0,897 g/ml = 0,914 grams (its a bit less then 1, you need to recalculate it.. (I rounded the numbers))
I just noticed a mistake, you need 1 mgrams not 1gram!

So 1 gram is 1000 ppm more then 1mg.

So if you take 1 gram (1,02ml) and add this in 998,98ml , totaling 1 gram in 1000ml or 1gram in 1 liter, you have 1000ppm = 1000g/m3 = 1000mg/L (remember that: ppm = 1g/m3 = 1mg/L)

So to have 1000pm, you dont need 1 gram, but 0,1 gram.

I hope there are not mistakes this time.

But its pretty simple in the end:

1 ppm means 1 part per million, and you know that 1 ppm = 1g/m3 = 1mg/L (or 1ppm = 1mg/kg = 1μg/g)
So you should be able to figure it out yourself now.
If you don't know it, then ask it! Better to ask and look foolish to some then not ask and stay stupid.

### #12 chandch

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Posted 12 December 2012 - 12:31 AM

Thank you.

### #13 pito

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Posted 12 December 2012 - 10:00 AM

chandch, on 12 December 2012 - 12:31 AM, said:

Thank you.

Just make sure you understand the logic behind it.
There is no point in memorising formulas.

An re-calculate it, its possible I might an error somewhere.
If you don't know it, then ask it! Better to ask and look foolish to some then not ask and stay stupid.

### #14 prabhubct

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Posted 12 December 2012 - 11:08 AM

1mg/106 mg (PPM)

Does density of solutions needs consideration? some solutions have less volume/kg other higher.

Edited by prabhubct, 12 December 2012 - 11:09 AM.

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### #15 pito

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Posted 12 December 2012 - 11:38 AM

prabhubct, on 12 December 2012 - 11:08 AM, said:

1mg/106 mg (PPM)

Does density of solutions needs consideration? some solutions have less volume/kg other higher.
Yes it matters.

If you work with a solution and not a powder for example, it matters.

Its the "substance/powder" that matters, not the fluid in wich it is dissolved.
If you don't know it, then ask it! Better to ask and look foolish to some then not ask and stay stupid.