echemi logo
Product
  • Product
  • Supplier
  • Inquiry
    Home > Chemicals Industry > Chemical Technology > Determination of melengestrol acetate, chlorgestrol acetate and megestrol acetate residues in milk and milk powder

    Determination of melengestrol acetate, chlorgestrol acetate and megestrol acetate residues in milk and milk powder

    • Last Update: 2021-09-20
    • Source: Internet
    • Author: User
    Search more information of high quality chemicals, good prices and reliable suppliers, visit www.echemi.com

    8.
    2.
    2.
    5 Sample preparation

    (1) Sample preparation

    Take 500g of sample, stir and mix well, put it into a clean container as a sample, seal it, and mark it with a mark
    .


    If the prepared sample is not measured immediately, store the test sample at 4°C


    (2) Sample weighing

    a.
    Milk sample Weigh 10g (accurate to 0.
    01g) milk sample and place it in a 50mL polypropylene centrifuge tube with a stopper
    .

    b.
    Milk powder sample Weigh 1g sample (accurate to 0.
    01g), place it in a 50mL polypropylene centrifuge tube with stopper, then add 8 times the mass of water to dissolve and mix
    .

    (3) Sample extraction

    Add 1.
    0mL ammonia and mix well
    .


    Was added 10mL 95% ethanol was added 10mL after mixing with ethyl acetate , shaken for 1min, then was added 10mL of petroleum ether , shaking the same 1min, to / centrifugation min 4000r 5min, draw the upper extract containing 15g through anhydrous sodium sulfate to Filter the glass column into a 50 mL polypropylene centrifuge tube with a stopper


    Add 5 mL of acetonitrile and keep it in a 60°C water bath for 3 minutes to melt the fat
    .


    Vortex for 1 min, centrifuge at 4000 r/min at -5°C for 7 min, draw the supernatant into a 15 mL stoppered polypropylene centrifuge tube, add 5 mL of acetonitrile to the precipitate and repeat the extraction once, and combine the supernatants


    (4) Saponification

    Add 4mL n-hexane, 1mL sodium hydroxide solution and 0.
    5mL magnesium chloride solution to the acetonitrile extract in sequence , mix quickly on a liquid mixer for 10s, keep in a 60℃ water bath for 15min, and at -5℃ at 4000r/min Centrifuge for 5 min, and transfer the supernatant to a 15 mL centrifuge tube
    .


    Add 4 mL of n-hexane to the precipitate, mix well, heat in a water bath at 60°C for 15 minutes, centrifuge at 4000r/min at -5°C for 5 minutes, and combine the supernatants


    (4) Saponification

    Add 4mL n-hexane, 1mL sodium hydroxide solution and 0.
    5mL magnesium chloride solution to the acetonitrile extract in sequence, mix quickly on a liquid mixer for 10s, keep in a 60℃ water bath for 15min, and at -5℃ at 4000r/min Centrifuge for 5 min, and transfer the supernatant to a 15 mL centrifuge tube
    .


    Add 4 mL of n-hexane to the precipitate, mix well, heat in a water bath at 60°C for 15 minutes, centrifuge at -5°C at 4000 r/min for 5 minutes, and combine the supernatants


    (5) Purification

    The above sample solution was transferred to the cyanopropyl solid phase extraction column, the glass test tube was rinsed twice with 2 mL of n-hexane, and the washing liquid was also transferred to the solid phase extraction column
    .


    After the sample solution flows out, wash the solid phase extraction column with 5 mL n-hexane and 6 mL ethyl acetate + n-hexane solution (1+19, v/v) in sequence.


     

     

    This article is an English version of an article which is originally in the Chinese language on echemi.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to service@echemi.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

    Related Articles

    Contact Us

    The source of this page with content of products and services is from Internet, which doesn't represent ECHEMI's opinion. If you have any queries, please write to service@echemi.com. It will be replied within 5 days.

    Moreover, if you find any instances of plagiarism from the page, please send email to service@echemi.com with relevant evidence.