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pmol/uL to g/100g

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  • Gerleene
    replied
    thank you very much, it helped me thinking about the 0.3mg (0.0003g) and from there I used for mg/g:
    Lys mw= 146.2g/mol
    Lys 97.1pmol/uL X 200uL = 19420pmol
    19420pmol X umol/1000000pmol X 146.2ug/umol= 2.84ug
    2.84ug X 1mg/1000ug X 1/0.0003g = 9.46mg/g
    I think that's the correct result for Lysine: 9.46mg/g
    thank you very much, it helped me understand more

    Leave a comment:


  • JohnS
    replied
    Originally posted by Gerleene View Post
    Sorry, I hydrolyzed 15mg of ground sample with 1mL of 6N HCl and took 20uL of hydrolysate and evaporated completely, than I reconstituted with 200uL of ultrapure water; after filtering, was injected into HPLC. I obtained 97.1pmol/uL of Lysine and the mw of lysine is 146.2g/mol. I need to calculate for each of the amino acids to calculate the protein in sample but I just want to use Lysine as an example to find out how I need to calculate each of the amino acids in my sample.
    I am not 100% sure of this, but I think it will help
    You took only 20 無 of the 1000 無 hydrolysate, so only 15 mg x 20無/1000 無 of the original sample = 0.30 mg (or its reacted product) is in the evaporated residue, as you then diluted it in 200 無 of water, you are working with a 0.30mg/200 無 solution or 1.5 ng/無 solution (The issue is any reaction that changed the mass of the material)

    Now working with the lysine result, you got a concentration of 97.1 pmol/無, but you have a total of 200 無, so 19.42 nmol of lysine, BUT the total amount of the 15 mg sample that made it to your 200 無 is 1/50 of the original sample, so in the original sample you had 50 x 19.42 nmol lysine or 971 nmol lysine.

    At any point, you may multiply by molar mass, 971 nmol lysine x 146.2 g/mol141.96 痢 lysine

    We used to have a chemist, Mrs X, who posted here regularly, but she hasn't for some time. I'd like for her to review the above, but it reflects my understanding of similar problems that have been worked here in the past (but I am an EE not a chemist).

    Leave a comment:


  • Gerleene
    replied
    Sorry, I hydrolyzed 15mg of ground sample with 1mL of 6N HCl and took 20uL of hydrolysate and evaporated completely, than I reconstituted with 200uL of ultrapure water; after filtering, was injected into HPLC. I obtained 97.1pmol/uL of Lysine and the mw of lysine is 146.2g/mol. I need to calculate for each of the amino acids to calculate the protein in sample but I just want to use Lysine as an example to find out how I need to calculate each of the amino acids in my sample.

    Leave a comment:


  • JohnS
    replied
    Originally posted by Gerleene View Post
    Please help,
    I hydrolyzed 15mg of sample, took 20uL of it, which evaporated and eventually reconstituted into 200uL of water and injected into HPLC, the result is giving me 97.1pmol/uL (based on my calibration curve) of Lysine, how do I convert it either to g/100g (%) or mg/g?
    I have an idea but want to make sure I'm doing it correctly.
    thank you very much!
    I believe we are missing two critical pieces of data:
    1) "I hydrolyzed 15mg of sample" On what volume of water (or solvent)? We need the concentration
    2) "97.1pmol/uL" What is the substance? We need the molar mass to convert between moles and grams.

    Leave a comment:


  • Gerleene
    started a topic pmol/uL to g/100g

    pmol/uL to g/100g

    Please help,
    I hydrolyzed 15mg of sample, took 20uL of it, which evaporated and eventually reconstituted into 200uL of water and injected into HPLC, the result is giving me 97.1pmol/uL (based on my calibration curve) of Lysine, how do I convert it either to g/100g (%) or mg/g?
    I have an idea but want to make sure I'm doing it correctly.
    thank you very much!
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